RC Flight Data Recorder Help
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I would like to make a Flight Recorder for my R/C helicopter. We have had
quite a few guys crash from "lockouts" and cant figure out what happened.
Is this possible to do? Here is what I would like it to do:
1. Record all inputs to the servos and make info available to download to
PC and analyze later on
2. Record Radio glitches
3. Track battery power and show if it peaks, slumps or goes dead.
It would be nice to see this information over a time line so you can
analyze it later ans see that a spike in battery caused a glitch, etc. Is
this possible, and can anyone help me with resources on getting started?
Thanks,
Matt Johnson
quite a few guys crash from "lockouts" and cant figure out what happened.
Is this possible to do? Here is what I would like it to do:
1. Record all inputs to the servos and make info available to download to
PC and analyze later on
2. Record Radio glitches
3. Track battery power and show if it peaks, slumps or goes dead.
It would be nice to see this information over a time line so you can
analyze it later ans see that a spike in battery caused a glitch, etc. Is
this possible, and can anyone help me with resources on getting started?
Thanks,
Matt Johnson
Comments
suddenly and for so short a duration, that the stamp chip would likely miss
it. Next, would be memory requirements as to how many samples per second you
want to store, and then how much memory you need to hold that data. Then you
would multiply that by the number of channels for the things you want to
monitor. That would give you an idea as to how much memory you need.
The problem is EEprom or Flash RAM may be too slow to receive this much data
as you do need it to be non volatile as well?
In RC, the transmitter sends a series of pulses, one for each channel in
sequence, pauses for a tiny bit and repeats the process. The width of the
pulse tells the server how much to move left or right. Usually 1.5 ms pulse
is center and 1 ms is full right and 2 ms is full left or vice versa. The
Receiver simply uses a simple circuit to decode the pulses and send them to
their appropriate servo channels. You would need to tap into this main
signal going to the decoder and monitor it. But then what are you wanting to
monitor and how much RAM do you need to do it.
From my calcs, you'd probably need something like 2 to 6 gigabytes of
datastorage to hold several minutes of information, if you want detailed
coverage, so maybe a 2.5 inch HD might work, or lots of flash ram, maybe
using the one wire large capacity chips in series would do. But at the
sampling rates you may still miss glitches, so the microntroller would need
to be really fast, maybe a BS2sx, but probsbly something faster even.
From what you stated in your message, it sounds like radio interference
from some other source. First you need to eliminate the other potential
sources, such as other flyer's turning on their radios on the same
frequency. Switch to FM (for rc choppers you should not be using AM at all).
Get a scanner for RC frequencies, and monitor all the channels your
interested in to see which ones have signals on them (eg, construction site
cranes being operated by radio control, warehouse overhead lift operated by
radio). If you find some, avoid those channels. You may find that someone is
running RC cars or boats down the street on the same channels you are
(instead of car's on one set, and planes on another).
Lockouts usually mean someone turned on their radio on the same channel
someone else is using jamming out the signal in the receiver with
contradicting pulses. I would get a scanner or build a scanner to monitor
the channels I am interested in. Now this would be a better use for a Stamp.
You could maybe get a receiver, and several crystals for the channles your
interested in, setup a crystal switchin circuit, so you can change channels
programatically, and hook into the decode input circuit to monitor the pulse
trains and/or RF signal strength. Then display and or print that out. Using
a printout saves RAm as you don't have to store the info in precious memory
(Stamps don't have a lot of this).
Anyway, that's my two bits worth.
Good luck
Earl
Original Message
From: Matt Johnson [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=iHgXUxakd4C7MhwpSYmu_9dtvLkFovmO2EinXnND-K0OpL50ZaX_RuHGGtXRWxgsp8z9kqUqXA]matt@m...[/url
Sent: Saturday, December 01, 2001 12:22 AM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] RC Flight Data Recorder Help
I would like to make a Flight Recorder for my R/C helicopter. We have had
quite a few guys crash from "lockouts" and cant figure out what happened.
Is this possible to do? Here is what I would like it to do:
1. Record all inputs to the servos and make info available to download to
PC and analyze later on
2. Record Radio glitches
3. Track battery power and show if it peaks, slumps or goes dead.
It would be nice to see this information over a time line so you can
analyze it later ans see that a spike in battery caused a glitch, etc. Is
this possible, and can anyone help me with resources on getting started?
Thanks,
Matt Johnson
To UNSUBSCRIBE, just send mail to:
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generate a huge amount of data. probably the better way to do it would be to
analyze every pulse received by the radio and if a problem is found then log
the data that is bad and maybe when that bad stream of data began.
http://www.inetport.com/~davisele/fc.html
Richard
Original Message
From: "Matt Johnson" <matt@m...>
To: <basicstamps@yahoogroups.com>
Sent: Saturday, December 01, 2001 12:21 AM
Subject: [noparse][[/noparse]basicstamps] RC Flight Data Recorder Help
>
>
> I would like to make a Flight Recorder for my R/C helicopter. We have had
> quite a few guys crash from "lockouts" and cant figure out what happened.
> Is this possible to do? Here is what I would like it to do:
>
> 1. Record all inputs to the servos and make info available to download to
> PC and analyze later on
>
> 2. Record Radio glitches
>
> 3. Track battery power and show if it peaks, slumps or goes dead.
>
> It would be nice to see this information over a time line so you can
> analyze it later ans see that a spike in battery caused a glitch, etc. Is
> this possible, and can anyone help me with resources on getting started?
>
> Thanks,
> Matt Johnson
>
>
>
>
>
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
much HD space. We are flying PCM by the way, not FM or AM. We have had
these lockouts at different fields with no people flying, so I am not sure
about interference. Common lockouts for RC Heli's is metal on metal
vibrating or other airframe type problems. I was thinking of trying to
trap those. We have also thought that maybe it was a battery suddenly
dying or a switch short circuiting because the heli that locked out this
last time had failsafe set to put throttle to idle and when it locked out
it didnt go to idle making us think that maybe it didnt loose frequency
since it didnt go to failsafe... Would it be more possible instead of
logging to just record 'glitches' and show the time of the last glitch or
something like that?
Does anyone have schematics to build a Spectrum analyzer like you were
talking about at the end? that would be nice to have regardless. I think
the RC channels for helis are 75mhz...
- Matt
On Sat, 1 Dec 2001, Earl Bollinger wrote:
> Yes it's doable. But the problem is spikes in voltage (glitches) happen so
> suddenly and for so short a duration, that the stamp chip would likely miss
> it. Next, would be memory requirements as to how many samples per second you
> want to store, and then how much memory you need to hold that data. Then you
> would multiply that by the number of channels for the things you want to
> monitor. That would give you an idea as to how much memory you need.
> The problem is EEprom or Flash RAM may be too slow to receive this much data
> as you do need it to be non volatile as well?
> In RC, the transmitter sends a series of pulses, one for each channel in
> sequence, pauses for a tiny bit and repeats the process. The width of the
> pulse tells the server how much to move left or right. Usually 1.5 ms pulse
> is center and 1 ms is full right and 2 ms is full left or vice versa. The
> Receiver simply uses a simple circuit to decode the pulses and send them to
> their appropriate servo channels. You would need to tap into this main
> signal going to the decoder and monitor it. But then what are you wanting to
> monitor and how much RAM do you need to do it.
> From my calcs, you'd probably need something like 2 to 6 gigabytes of
> datastorage to hold several minutes of information, if you want detailed
> coverage, so maybe a 2.5 inch HD might work, or lots of flash ram, maybe
> using the one wire large capacity chips in series would do. But at the
> sampling rates you may still miss glitches, so the microntroller would need
> to be really fast, maybe a BS2sx, but probsbly something faster even.
> From what you stated in your message, it sounds like radio interference
> from some other source. First you need to eliminate the other potential
> sources, such as other flyer's turning on their radios on the same
> frequency. Switch to FM (for rc choppers you should not be using AM at all).
> Get a scanner for RC frequencies, and monitor all the channels your
> interested in to see which ones have signals on them (eg, construction site
> cranes being operated by radio control, warehouse overhead lift operated by
> radio). If you find some, avoid those channels. You may find that someone is
> running RC cars or boats down the street on the same channels you are
> (instead of car's on one set, and planes on another).
> Lockouts usually mean someone turned on their radio on the same channel
> someone else is using jamming out the signal in the receiver with
> contradicting pulses. I would get a scanner or build a scanner to monitor
> the channels I am interested in. Now this would be a better use for a Stamp.
> You could maybe get a receiver, and several crystals for the channles your
> interested in, setup a crystal switchin circuit, so you can change channels
> programatically, and hook into the decode input circuit to monitor the pulse
> trains and/or RF signal strength. Then display and or print that out. Using
> a printout saves RAm as you don't have to store the info in precious memory
> (Stamps don't have a lot of this).
>
> Anyway, that's my two bits worth.
> Good luck
> Earl
>
>
Original Message
> From: Matt Johnson [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=66suwgxnwCdzTWEGmJoJubEKQIBb3mPn-Rz-ihqM0Wd2gUAXBebIGjqD0r1feHpk9jucyQ]matt@m...[/url
> Sent: Saturday, December 01, 2001 12:22 AM
> To: basicstamps@yahoogroups.com
> Subject: [noparse][[/noparse]basicstamps] RC Flight Data Recorder Help
>
>
>
>
> I would like to make a Flight Recorder for my R/C helicopter. We have had
> quite a few guys crash from "lockouts" and cant figure out what happened.
> Is this possible to do? Here is what I would like it to do:
>
> 1. Record all inputs to the servos and make info available to download to
> PC and analyze later on
>
> 2. Record Radio glitches
>
> 3. Track battery power and show if it peaks, slumps or goes dead.
>
> It would be nice to see this information over a time line so you can
> analyze it later ans see that a spike in battery caused a glitch, etc. Is
> this possible, and can anyone help me with resources on getting started?
>
> Thanks,
> Matt Johnson
>
>
>
>
>
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
> Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and Body
of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>
Nice site! It is neat to see someone who is doing stamp/electronics
projects with RC Helicopters. That night blade project has got to be the
coolest. The link for your 'Flight Data from my on-board computer data
logger' seems to be broken though. I would like to see that. does it do
what I am talking about? I am sure you have already thought out the
scenerio that I proposed.
Also, where is the fly-by-wire project? I didnt see it in your list?
- Matt
On Sat, 1 Dec 2001, Richard Friedrich wrote:
> It would be easy to change my fly-by-wire system . . . But you would
> generate a huge amount of data. probably the better way to do it would be to
> analyze every pulse received by the radio and if a problem is found then log
> the data that is bad and maybe when that bad stream of data began.
>
> http://www.inetport.com/~davisele/fc.html
> Richard
>
>
>
Original Message
> From: "Matt Johnson" <matt@m...>
> To: <basicstamps@yahoogroups.com>
> Sent: Saturday, December 01, 2001 12:21 AM
> Subject: [noparse][[/noparse]basicstamps] RC Flight Data Recorder Help
>
>
> >
> >
> > I would like to make a Flight Recorder for my R/C helicopter. We have had
> > quite a few guys crash from "lockouts" and cant figure out what happened.
> > Is this possible to do? Here is what I would like it to do:
> >
> > 1. Record all inputs to the servos and make info available to download to
> > PC and analyze later on
> >
> > 2. Record Radio glitches
> >
> > 3. Track battery power and show if it peaks, slumps or goes dead.
> >
> > It would be nice to see this information over a time line so you can
> > analyze it later ans see that a spike in battery caused a glitch, etc. Is
> > this possible, and can anyone help me with resources on getting started?
> >
> > Thanks,
> > Matt Johnson
> >
> >
> >
> >
> >
> >
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed. Text in the Subject and
> Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
> >
> >
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and Body
of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>
with all that metal to metal contact going on.
In my experiences, I always use a new on/off switch, I check it out
carefully before I do that even.
The servos are new, and tested carefully as well. I build my own battery
packs, as the store bought ones
tend to be sloppily made as well. I run the receiver off a separate battery
pack from the servos, I put in diodes across each cell, so I a cell
dies/opens the batter pack will still work at reduced volatage, especially
important if you use retracts in a airplane. If a servo stalls it doesn't
kill the receiver. If possible the receiver should be able to operate down
to 3 volts, important if you lose a cell in flight. Watch out for the six
volt packs some receivers and servos act flaky at the higher voltages, but
six volts can be a plus too.
If you have a lock out and crash hard, chunk the flight pack, as the crystal
or the ceramic filters may be cracked, causing intermittent operation, or a
coil may be damaged. I am amazed at the large number of people who try and
reuse radio equipment after a crash, it always leads to more grief. I'd
rather replace stuff than having to replace and straighten all those little
metal parts after a crash. It's a lot of hassle getting the rotor head and
such all working again just right. The radio is cheaper. That leads to
another point, the radio gear could be bad, or caused to go bad. The
transmitter could be defective. I had a transmitter once with a bad joystick
pot flake out if you happened
to move to just the right spot.
Glitch checking is a definite possiblity, but the system has to be
readable after a crash. So you have to make it survivable. I have no scanner
schematic, the last scanner I built, used a Airtronics receiver, and several
crystals for the frequencies I wanted to monitor. I would use the MCU to
swap out Xtals and check each channel for a signal.
I put in LED's to light up if a signal was detected. I used the decoder to
check the servo/channel pulses. Another approach would be to use several
receivers and just check the signal for each one. Receivers are pretty
economical nowadays. Many years ago when I was the QC guy at Proline (if
anyone remembers them), this stuff was really expensive. Servos were
repairable way back then, but today they are all throwaway items. The
scanner's nice as a MCU could output data to a serial port to a lap top
where you could run a VB program to store the data on a HD. You could even
monitor your own transmitter signal to see what it;s doing.
A glitch detector could be a op amp with it's threshold set slightly above
VCC (out of the noise) and you watch for the trigger (maybe a latch to catch
it, if it's really fast). Another op amp can be set to look for VCC going
down as well, in case you have a bad connection or a intermittent short
someplace.
Original Message
From: "Matt Johnson" <matt@m...>
To: <basicstamps@yahoogroups.com>
Sent: Saturday, December 01, 2001 10:59 AM
Subject: RE: [noparse][[/noparse]basicstamps] RC Flight Data Recorder Help
> Thanks Earl, that really helps. I didnt realize that logging would take so
> much HD space. We are flying PCM by the way, not FM or AM. We have had
> these lockouts at different fields with no people flying, so I am not sure
> about interference. Common lockouts for RC Heli's is metal on metal
> vibrating or other airframe type problems. I was thinking of trying to
> trap those. We have also thought that maybe it was a battery suddenly
> dying or a switch short circuiting because the heli that locked out this
> last time had failsafe set to put throttle to idle and when it locked out
> it didnt go to idle making us think that maybe it didnt loose frequency
> since it didnt go to failsafe... Would it be more possible instead of
> logging to just record 'glitches' and show the time of the last glitch or
> something like that?
>
> Does anyone have schematics to build a Spectrum analyzer like you were
> talking about at the end? that would be nice to have regardless. I think
> the RC channels for helis are 75mhz...
>
> - Matt
>
> On Sat, 1 Dec 2001, Earl Bollinger wrote:
>
> > Yes it's doable. But the problem is spikes in voltage (glitches)
happen so
> > suddenly and for so short a duration, that the stamp chip would likely
miss
> > it. Next, would be memory requirements as to how many samples per second
you
> > want to store, and then how much memory you need to hold that data. Then
you
> > would multiply that by the number of channels for the things you want to
> > monitor. That would give you an idea as to how much memory you need.
> > The problem is EEprom or Flash RAM may be too slow to receive this much
data
> > as you do need it to be non volatile as well?
> > In RC, the transmitter sends a series of pulses, one for each channel
in
> > sequence, pauses for a tiny bit and repeats the process. The width of
the
> > pulse tells the server how much to move left or right. Usually 1.5 ms
pulse
> > is center and 1 ms is full right and 2 ms is full left or vice versa.
The
> > Receiver simply uses a simple circuit to decode the pulses and send them
to
> > their appropriate servo channels. You would need to tap into this main
> > signal going to the decoder and monitor it. But then what are you
wanting to
> > monitor and how much RAM do you need to do it.
> > From my calcs, you'd probably need something like 2 to 6 gigabytes of
> > datastorage to hold several minutes of information, if you want detailed
> > coverage, so maybe a 2.5 inch HD might work, or lots of flash ram, maybe
> > using the one wire large capacity chips in series would do. But at the
> > sampling rates you may still miss glitches, so the microntroller would
need
> > to be really fast, maybe a BS2sx, but probsbly something faster even.
> > From what you stated in your message, it sounds like radio
interference
> > from some other source. First you need to eliminate the other potential
> > sources, such as other flyer's turning on their radios on the same
> > frequency. Switch to FM (for rc choppers you should not be using AM at
all).
> > Get a scanner for RC frequencies, and monitor all the channels your
> > interested in to see which ones have signals on them (eg, construction
site
> > cranes being operated by radio control, warehouse overhead lift operated
by
> > radio). If you find some, avoid those channels. You may find that
someone is
> > running RC cars or boats down the street on the same channels you are
> > (instead of car's on one set, and planes on another).
> > Lockouts usually mean someone turned on their radio on the same channel
> > someone else is using jamming out the signal in the receiver with
> > contradicting pulses. I would get a scanner or build a scanner to
monitor
> > the channels I am interested in. Now this would be a better use for a
Stamp.
> > You could maybe get a receiver, and several crystals for the channles
your
> > interested in, setup a crystal switchin circuit, so you can change
channels
> > programatically, and hook into the decode input circuit to monitor the
pulse
> > trains and/or RF signal strength. Then display and or print that out.
Using
> > a printout saves RAm as you don't have to store the info in precious
memory
> > (Stamps don't have a lot of this).
> >
> > Anyway, that's my two bits worth.
> > Good luck
> > Earl
> >
> >
Original Message
> > From: Matt Johnson [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=AygBSrU4Zsckp5KLgua8LNSb-5_vXKizt7BmqgdF3fXZvZ1v2RKPm06lKukPVZp6AhAErA]matt@m...[/url
> > Sent: Saturday, December 01, 2001 12:22 AM
> > To: basicstamps@yahoogroups.com
> > Subject: [noparse][[/noparse]basicstamps] RC Flight Data Recorder Help
> >
> >
> >
> >
> > I would like to make a Flight Recorder for my R/C helicopter. We have
had
> > quite a few guys crash from "lockouts" and cant figure out what
happened.
> > Is this possible to do? Here is what I would like it to do:
> >
> > 1. Record all inputs to the servos and make info available to download
to
> > PC and analyze later on
> >
> > 2. Record Radio glitches
> >
> > 3. Track battery power and show if it peaks, slumps or goes dead.
> >
> > It would be nice to see this information over a time line so you can
> > analyze it later ans see that a spike in battery caused a glitch, etc.
Is
> > this possible, and can anyone help me with resources on getting started?
> >
> > Thanks,
> > Matt Johnson
> >
> >
> >
> >
> >
> >
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed. Text in the Subject
and
> > Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
> >
> >
> >
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed. Text in the Subject
and Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
> >
> >
> >
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
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>
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>
>
and altitude
the fly by wire is part of the uav project
http://www.inetport.com/~davisele/uav.html
have you checked out the bc-6 glitch counter?
richard
Original Message
From: "Matt Johnson" <matt@m...>
To: <basicstamps@yahoogroups.com>
Sent: Saturday, December 01, 2001 11:08 AM
Subject: Re: [noparse][[/noparse]basicstamps] RC Flight Data Recorder Help
> Richard,
>
> Nice site! It is neat to see someone who is doing stamp/electronics
> projects with RC Helicopters. That night blade project has got to be the
> coolest. The link for your 'Flight Data from my on-board computer data
> logger' seems to be broken though. I would like to see that. does it do
> what I am talking about? I am sure you have already thought out the
> scenerio that I proposed.
>
> Also, where is the fly-by-wire project? I didnt see it in your list?
>
> - Matt
>
> On Sat, 1 Dec 2001, Richard Friedrich wrote:
>
> > It would be easy to change my fly-by-wire system . . . But you would
> > generate a huge amount of data. probably the better way to do it would
be to
> > analyze every pulse received by the radio and if a problem is found then
log
> > the data that is bad and maybe when that bad stream of data began.
> >
> > http://www.inetport.com/~davisele/fc.html
> > Richard
> >
> >
> >
Original Message
> > From: "Matt Johnson" <matt@m...>
> > To: <basicstamps@yahoogroups.com>
> > Sent: Saturday, December 01, 2001 12:21 AM
> > Subject: [noparse][[/noparse]basicstamps] RC Flight Data Recorder Help
> >
> >
> > >
> > >
> > > I would like to make a Flight Recorder for my R/C helicopter. We have
had
> > > quite a few guys crash from "lockouts" and cant figure out what
happened.
> > > Is this possible to do? Here is what I would like it to do:
> > >
> > > 1. Record all inputs to the servos and make info available to download
to
> > > PC and analyze later on
> > >
> > > 2. Record Radio glitches
> > >
> > > 3. Track battery power and show if it peaks, slumps or goes dead.
> > >
> > > It would be nice to see this information over a time line so you can
> > > analyze it later ans see that a spike in battery caused a glitch, etc.
Is
> > > this possible, and can anyone help me with resources on getting
started?
> > >
> > > Thanks,
> > > Matt Johnson
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > To UNSUBSCRIBE, just send mail to:
> > > basicstamps-unsubscribe@yahoogroups.com
> > > from the same email address that you subscribed. Text in the Subject
and
> > Body of the message will be ignored.
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
> > >
> > >
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed. Text in the Subject
and Body of the message will be ignored.
> >
> >
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http://docs.yahoo.com/info/terms/
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> >
> >
>
>
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www.rchelicopters.org which has a reviews area. I will check it out.
- Matt
On Sat, 1 Dec 2001, Richard Friedrich wrote:
> the flight data is broken but it was not what you wanted - it was airspeed
> and altitude
>
> the fly by wire is part of the uav project
> http://www.inetport.com/~davisele/uav.html
>
> have you checked out the bc-6 glitch counter?
>
>
> richard
>
>
>
>
Original Message
> From: "Matt Johnson" <matt@m...>
> To: <basicstamps@yahoogroups.com>
> Sent: Saturday, December 01, 2001 11:08 AM
> Subject: Re: [noparse][[/noparse]basicstamps] RC Flight Data Recorder Help
>
>
> > Richard,
> >
> > Nice site! It is neat to see someone who is doing stamp/electronics
> > projects with RC Helicopters. That night blade project has got to be the
> > coolest. The link for your 'Flight Data from my on-board computer data
> > logger' seems to be broken though. I would like to see that. does it do
> > what I am talking about? I am sure you have already thought out the
> > scenerio that I proposed.
> >
> > Also, where is the fly-by-wire project? I didnt see it in your list?
> >
> > - Matt
> >
> > On Sat, 1 Dec 2001, Richard Friedrich wrote:
> >
> > > It would be easy to change my fly-by-wire system . . . But you would
> > > generate a huge amount of data. probably the better way to do it would
> be to
> > > analyze every pulse received by the radio and if a problem is found then
> log
> > > the data that is bad and maybe when that bad stream of data began.
> > >
> > > http://www.inetport.com/~davisele/fc.html
> > > Richard
> > >
> > >
> > >
Original Message
> > > From: "Matt Johnson" <matt@m...>
> > > To: <basicstamps@yahoogroups.com>
> > > Sent: Saturday, December 01, 2001 12:21 AM
> > > Subject: [noparse][[/noparse]basicstamps] RC Flight Data Recorder Help
> > >
> > >
> > > >
> > > >
> > > > I would like to make a Flight Recorder for my R/C helicopter. We have
> had
> > > > quite a few guys crash from "lockouts" and cant figure out what
> happened.
> > > > Is this possible to do? Here is what I would like it to do:
> > > >
> > > > 1. Record all inputs to the servos and make info available to download
> to
> > > > PC and analyze later on
> > > >
> > > > 2. Record Radio glitches
> > > >
> > > > 3. Track battery power and show if it peaks, slumps or goes dead.
> > > >
> > > > It would be nice to see this information over a time line so you can
> > > > analyze it later ans see that a spike in battery caused a glitch, etc.
> Is
> > > > this possible, and can anyone help me with resources on getting
> started?
> > > >
> > > > Thanks,
> > > > Matt Johnson
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > > To UNSUBSCRIBE, just send mail to:
> > > > basicstamps-unsubscribe@yahoogroups.com
> > > > from the same email address that you subscribed. Text in the Subject
> and
> > > Body of the message will be ignored.
> > > >
> > > >
> > > > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
> > > >
> > > >
> > >
> > >
> > > To UNSUBSCRIBE, just send mail to:
> > > basicstamps-unsubscribe@yahoogroups.com
> > > from the same email address that you subscribed. Text in the Subject
> and Body of the message will be ignored.
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
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> > >
> > >
> > >
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
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> Body of the message will be ignored.
> >
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> >
> >
>
>
> To UNSUBSCRIBE, just send mail to:
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>
I am curious how you put a diode across each cell in the battery pack such
that if a cell dies the battery pack continues to operate at a reduced
voltage. If the diode you use is forward biased it will drain current from
the battery cell. If it is reversed biased it will not be conducting any
current. open ckt. Please explain, tnx Steve.
Original Message
From: "Earl Bollinger" <earlwb@w...>
To: <basicstamps@yahoogroups.com>
Sent: Saturday, December 01, 2001 10:28 AM
Subject: Re: [noparse][[/noparse]basicstamps] RC Flight Data Recorder Help
> In my many years of RC'ing, helos were always pretty picky about RF noise,
> with all that metal to metal contact going on.
> In my experiences, I always use a new on/off switch, I check it out
> carefully before I do that even.
> The servos are new, and tested carefully as well. I build my own battery
> packs, as the store bought ones
> tend to be sloppily made as well. I run the receiver off a separate
battery
> pack from the servos, I put in diodes across each cell, so I a cell
> dies/opens the batter pack will still work at reduced volatage, especially
> important if you use retracts in a airplane. If a servo stalls it doesn't
> kill the receiver. If possible the receiver should be able to operate down
> to 3 volts, important if you lose a cell in flight. Watch out for the six
> volt packs some receivers and servos act flaky at the higher voltages, but
> six volts can be a plus too.
> If you have a lock out and crash hard, chunk the flight pack, as the
crystal
> or the ceramic filters may be cracked, causing intermittent operation, or
a
> coil may be damaged. I am amazed at the large number of people who try and
> reuse radio equipment after a crash, it always leads to more grief. I'd
> rather replace stuff than having to replace and straighten all those
little
> metal parts after a crash. It's a lot of hassle getting the rotor head and
> such all working again just right. The radio is cheaper. That leads to
> another point, the radio gear could be bad, or caused to go bad. The
> transmitter could be defective. I had a transmitter once with a bad
joystick
> pot flake out if you happened
> to move to just the right spot.
> Glitch checking is a definite possiblity, but the system has to be
> readable after a crash. So you have to make it survivable. I have no
scanner
> schematic, the last scanner I built, used a Airtronics receiver, and
several
> crystals for the frequencies I wanted to monitor. I would use the MCU to
> swap out Xtals and check each channel for a signal.
> I put in LED's to light up if a signal was detected. I used the decoder to
> check the servo/channel pulses. Another approach would be to use several
> receivers and just check the signal for each one. Receivers are pretty
> economical nowadays. Many years ago when I was the QC guy at Proline (if
> anyone remembers them), this stuff was really expensive. Servos were
> repairable way back then, but today they are all throwaway items. The
> scanner's nice as a MCU could output data to a serial port to a lap top
> where you could run a VB program to store the data on a HD. You could even
> monitor your own transmitter signal to see what it;s doing.
> A glitch detector could be a op amp with it's threshold set slightly
above
> VCC (out of the noise) and you watch for the trigger (maybe a latch to
catch
> it, if it's really fast). Another op amp can be set to look for VCC going
> down as well, in case you have a bad connection or a intermittent short
> someplace.
>
Original Message
> From: "Matt Johnson" <matt@m...>
> To: <basicstamps@yahoogroups.com>
> Sent: Saturday, December 01, 2001 10:59 AM
> Subject: RE: [noparse][[/noparse]basicstamps] RC Flight Data Recorder Help
>
>
> > Thanks Earl, that really helps. I didnt realize that logging would take
so
> > much HD space. We are flying PCM by the way, not FM or AM. We have had
> > these lockouts at different fields with no people flying, so I am not
sure
> > about interference. Common lockouts for RC Heli's is metal on metal
> > vibrating or other airframe type problems. I was thinking of trying to
> > trap those. We have also thought that maybe it was a battery suddenly
> > dying or a switch short circuiting because the heli that locked out this
> > last time had failsafe set to put throttle to idle and when it locked
out
> > it didnt go to idle making us think that maybe it didnt loose frequency
> > since it didnt go to failsafe... Would it be more possible instead of
> > logging to just record 'glitches' and show the time of the last glitch
or
> > something like that?
> >
> > Does anyone have schematics to build a Spectrum analyzer like you were
> > talking about at the end? that would be nice to have regardless. I think
> > the RC channels for helis are 75mhz...
> >
> > - Matt
> >
> > On Sat, 1 Dec 2001, Earl Bollinger wrote:
> >
> > > Yes it's doable. But the problem is spikes in voltage (glitches)
> happen so
> > > suddenly and for so short a duration, that the stamp chip would likely
> miss
> > > it. Next, would be memory requirements as to how many samples per
second
> you
> > > want to store, and then how much memory you need to hold that data.
Then
> you
> > > would multiply that by the number of channels for the things you want
to
> > > monitor. That would give you an idea as to how much memory you need.
> > > The problem is EEprom or Flash RAM may be too slow to receive this
much
> data
> > > as you do need it to be non volatile as well?
> > > In RC, the transmitter sends a series of pulses, one for each
channel
> in
> > > sequence, pauses for a tiny bit and repeats the process. The width of
> the
> > > pulse tells the server how much to move left or right. Usually 1.5 ms
> pulse
> > > is center and 1 ms is full right and 2 ms is full left or vice versa.
> The
> > > Receiver simply uses a simple circuit to decode the pulses and send
them
> to
> > > their appropriate servo channels. You would need to tap into this main
> > > signal going to the decoder and monitor it. But then what are you
> wanting to
> > > monitor and how much RAM do you need to do it.
> > > From my calcs, you'd probably need something like 2 to 6 gigabytes
of
> > > datastorage to hold several minutes of information, if you want
detailed
> > > coverage, so maybe a 2.5 inch HD might work, or lots of flash ram,
maybe
> > > using the one wire large capacity chips in series would do. But at the
> > > sampling rates you may still miss glitches, so the microntroller would
> need
> > > to be really fast, maybe a BS2sx, but probsbly something faster even.
> > > From what you stated in your message, it sounds like radio
> interference
> > > from some other source. First you need to eliminate the other
potential
> > > sources, such as other flyer's turning on their radios on the same
> > > frequency. Switch to FM (for rc choppers you should not be using AM at
> all).
> > > Get a scanner for RC frequencies, and monitor all the channels your
> > > interested in to see which ones have signals on them (eg, construction
> site
> > > cranes being operated by radio control, warehouse overhead lift
operated
> by
> > > radio). If you find some, avoid those channels. You may find that
> someone is
> > > running RC cars or boats down the street on the same channels you are
> > > (instead of car's on one set, and planes on another).
> > > Lockouts usually mean someone turned on their radio on the same
channel
> > > someone else is using jamming out the signal in the receiver with
> > > contradicting pulses. I would get a scanner or build a scanner to
> monitor
> > > the channels I am interested in. Now this would be a better use for a
> Stamp.
> > > You could maybe get a receiver, and several crystals for the channles
> your
> > > interested in, setup a crystal switchin circuit, so you can change
> channels
> > > programatically, and hook into the decode input circuit to monitor the
> pulse
> > > trains and/or RF signal strength. Then display and or print that out.
> Using
> > > a printout saves RAm as you don't have to store the info in precious
> memory
> > > (Stamps don't have a lot of this).
> > >
> > > Anyway, that's my two bits worth.
> > > Good luck
> > > Earl
> > >
> > >
Original Message
> > > From: Matt Johnson [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=aqTXPrMPTBjHvE9AChjXnDuY-wTf1Ez0bSbGI1Y1_UYmrNmpySyyDjfMLa5y-KmL-A6c0A]matt@m...[/url
> > > Sent: Saturday, December 01, 2001 12:22 AM
> > > To: basicstamps@yahoogroups.com
> > > Subject: [noparse][[/noparse]basicstamps] RC Flight Data Recorder Help
> > >
> > >
> > >
> > >
> > > I would like to make a Flight Recorder for my R/C helicopter. We have
> had
> > > quite a few guys crash from "lockouts" and cant figure out what
> happened.
> > > Is this possible to do? Here is what I would like it to do:
> > >
> > > 1. Record all inputs to the servos and make info available to download
> to
> > > PC and analyze later on
> > >
> > > 2. Record Radio glitches
> > >
> > > 3. Track battery power and show if it peaks, slumps or goes dead.
> > >
> > > It would be nice to see this information over a time line so you can
> > > analyze it later ans see that a spike in battery caused a glitch, etc.
> Is
> > > this possible, and can anyone help me with resources on getting
started?
> > >
> > > Thanks,
> > > Matt Johnson
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > To UNSUBSCRIBE, just send mail to:
> > > basicstamps-unsubscribe@yahoogroups.com
> > > from the same email address that you subscribed. Text in the Subject
> and
> > > Body of the message will be ignored.
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
> > >
> > >
> > >
> > >
> > >
> > > To UNSUBSCRIBE, just send mail to:
> > > basicstamps-unsubscribe@yahoogroups.com
> > > from the same email address that you subscribed. Text in the Subject
> and Body of the message will be ignored.
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
> > >
> > >
> > >
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed. Text in the Subject
and
> Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
> >
> >
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
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>
>
>
The Basic circuit has a diode in series with the cell, and another diode
across the cell to the end of the diode.
Sort of like this:
*
*
**********
* *
Cell Diode
* *
diode *
**********
*
*
Thus the series diode blocks the flow back into the cell, and if a cell
opens the outer diode allows
power to still flow through the pack. If a cell shorts, it could block the
flow if it reverses, or still let current through.
Sorry, for taking so long, I had to open up a pack to see the circuit again.
I forgot about the other diode.
Anyway, I hope the asterisks line up vertically.
Original Message
From: "Stephen H Chapman" <chapman@t...>
To: <basicstamps@yahoogroups.com>
Sent: Sunday, December 02, 2001 12:34 AM
Subject: Re: [noparse][[/noparse]basicstamps] RC Flight Data Recorder Help
> Earl,
> I am curious how you put a diode across each cell in the battery pack such
> that if a cell dies the battery pack continues to operate at a reduced
> voltage. If the diode you use is forward biased it will drain current from
> the battery cell. If it is reversed biased it will not be conducting any
> current. open ckt. Please explain, tnx Steve.
>
Original Message
> From: "Earl Bollinger" <earlwb@w...>
> To: <basicstamps@yahoogroups.com>
> Sent: Saturday, December 01, 2001 10:28 AM
> Subject: Re: [noparse][[/noparse]basicstamps] RC Flight Data Recorder Help
>
>
> > In my many years of RC'ing, helos were always pretty picky about RF
noise,
> > with all that metal to metal contact going on.
> > In my experiences, I always use a new on/off switch, I check it out
> > carefully before I do that even.
> > The servos are new, and tested carefully as well. I build my own battery
> > packs, as the store bought ones
> > tend to be sloppily made as well. I run the receiver off a separate
> battery
> > pack from the servos, I put in diodes across each cell, so I a cell
> > dies/opens the batter pack will still work at reduced volatage,
especially
> > important if you use retracts in a airplane. If a servo stalls it
doesn't
> > kill the receiver. If possible the receiver should be able to operate
down
> > to 3 volts, important if you lose a cell in flight. Watch out for the
six
> > volt packs some receivers and servos act flaky at the higher voltages,
but
> > six volts can be a plus too.
> > If you have a lock out and crash hard, chunk the flight pack, as the
> crystal
> > or the ceramic filters may be cracked, causing intermittent operation,
or
> a
> > coil may be damaged. I am amazed at the large number of people who try
and
> > reuse radio equipment after a crash, it always leads to more grief. I'd
> > rather replace stuff than having to replace and straighten all those
> little
> > metal parts after a crash. It's a lot of hassle getting the rotor head
and
> > such all working again just right. The radio is cheaper. That leads to
> > another point, the radio gear could be bad, or caused to go bad. The
> > transmitter could be defective. I had a transmitter once with a bad
> joystick
> > pot flake out if you happened
> > to move to just the right spot.
> > Glitch checking is a definite possiblity, but the system has to be
> > readable after a crash. So you have to make it survivable. I have no
> scanner
> > schematic, the last scanner I built, used a Airtronics receiver, and
> several
> > crystals for the frequencies I wanted to monitor. I would use the MCU to
> > swap out Xtals and check each channel for a signal.
> > I put in LED's to light up if a signal was detected. I used the decoder
to
> > check the servo/channel pulses. Another approach would be to use several
> > receivers and just check the signal for each one. Receivers are pretty
> > economical nowadays. Many years ago when I was the QC guy at Proline (if
> > anyone remembers them), this stuff was really expensive. Servos were
> > repairable way back then, but today they are all throwaway items. The
> > scanner's nice as a MCU could output data to a serial port to a lap top
> > where you could run a VB program to store the data on a HD. You could
even
> > monitor your own transmitter signal to see what it;s doing.
> > A glitch detector could be a op amp with it's threshold set slightly
> above
> > VCC (out of the noise) and you watch for the trigger (maybe a latch to
> catch
> > it, if it's really fast). Another op amp can be set to look for VCC
going
> > down as well, in case you have a bad connection or a intermittent short
> > someplace.
> >
Original Message
> > From: "Matt Johnson" <matt@m...>
> > To: <basicstamps@yahoogroups.com>
> > Sent: Saturday, December 01, 2001 10:59 AM
> > Subject: RE: [noparse][[/noparse]basicstamps] RC Flight Data Recorder Help
> >
> >
> > > Thanks Earl, that really helps. I didnt realize that logging would
take
> so
> > > much HD space. We are flying PCM by the way, not FM or AM. We have had
> > > these lockouts at different fields with no people flying, so I am not
> sure
> > > about interference. Common lockouts for RC Heli's is metal on metal
> > > vibrating or other airframe type problems. I was thinking of trying to
> > > trap those. We have also thought that maybe it was a battery suddenly
> > > dying or a switch short circuiting because the heli that locked out
this
> > > last time had failsafe set to put throttle to idle and when it locked
> out
> > > it didnt go to idle making us think that maybe it didnt loose
frequency
> > > since it didnt go to failsafe... Would it be more possible instead of
> > > logging to just record 'glitches' and show the time of the last glitch
> or
> > > something like that?
> > >
> > > Does anyone have schematics to build a Spectrum analyzer like you were
> > > talking about at the end? that would be nice to have regardless. I
think
> > > the RC channels for helis are 75mhz...
> > >
> > > - Matt
> > >
> > > On Sat, 1 Dec 2001, Earl Bollinger wrote:
> > >
> > > > Yes it's doable. But the problem is spikes in voltage (glitches)
> > happen so
> > > > suddenly and for so short a duration, that the stamp chip would
likely
> > miss
> > > > it. Next, would be memory requirements as to how many samples per
> second
> > you
> > > > want to store, and then how much memory you need to hold that data.
> Then
> > you
> > > > would multiply that by the number of channels for the things you
want
> to
> > > > monitor. That would give you an idea as to how much memory you need.
> > > > The problem is EEprom or Flash RAM may be too slow to receive this
> much
> > data
> > > > as you do need it to be non volatile as well?
> > > > In RC, the transmitter sends a series of pulses, one for each
> channel
> > in
> > > > sequence, pauses for a tiny bit and repeats the process. The width
of
> > the
> > > > pulse tells the server how much to move left or right. Usually 1.5
ms
> > pulse
> > > > is center and 1 ms is full right and 2 ms is full left or vice
versa.
> > The
> > > > Receiver simply uses a simple circuit to decode the pulses and send
> them
> > to
> > > > their appropriate servo channels. You would need to tap into this
main
> > > > signal going to the decoder and monitor it. But then what are you
> > wanting to
> > > > monitor and how much RAM do you need to do it.
> > > > From my calcs, you'd probably need something like 2 to 6 gigabytes
> of
> > > > datastorage to hold several minutes of information, if you want
> detailed
> > > > coverage, so maybe a 2.5 inch HD might work, or lots of flash ram,
> maybe
> > > > using the one wire large capacity chips in series would do. But at
the
> > > > sampling rates you may still miss glitches, so the microntroller
would
> > need
> > > > to be really fast, maybe a BS2sx, but probsbly something faster
even.
> > > > From what you stated in your message, it sounds like radio
> > interference
> > > > from some other source. First you need to eliminate the other
> potential
> > > > sources, such as other flyer's turning on their radios on the same
> > > > frequency. Switch to FM (for rc choppers you should not be using AM
at
> > all).
> > > > Get a scanner for RC frequencies, and monitor all the channels your
> > > > interested in to see which ones have signals on them (eg,
construction
> > site
> > > > cranes being operated by radio control, warehouse overhead lift
> operated
> > by
> > > > radio). If you find some, avoid those channels. You may find that
> > someone is
> > > > running RC cars or boats down the street on the same channels you
are
> > > > (instead of car's on one set, and planes on another).
> > > > Lockouts usually mean someone turned on their radio on the same
> channel
> > > > someone else is using jamming out the signal in the receiver with
> > > > contradicting pulses. I would get a scanner or build a scanner to
> > monitor
> > > > the channels I am interested in. Now this would be a better use for
a
> > Stamp.
> > > > You could maybe get a receiver, and several crystals for the
channles
> > your
> > > > interested in, setup a crystal switchin circuit, so you can change
> > channels
> > > > programatically, and hook into the decode input circuit to monitor
the
> > pulse
> > > > trains and/or RF signal strength. Then display and or print that
out.
> > Using
> > > > a printout saves RAm as you don't have to store the info in precious
> > memory
> > > > (Stamps don't have a lot of this).
> > > >
> > > > Anyway, that's my two bits worth.
> > > > Good luck
> > > > Earl
> > > >
> > > >
Original Message
> > > > From: Matt Johnson [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=-g1cmaXPW62goPjL5NVGp9pD2qmtHEDJuetHUZPZaptixSaZv3nPgTym0NNLfi7bjlzuBFH1hTE]matt@m...[/url
> > > > Sent: Saturday, December 01, 2001 12:22 AM
> > > > To: basicstamps@yahoogroups.com
> > > > Subject: [noparse][[/noparse]basicstamps] RC Flight Data Recorder Help
> > > >
> > > >
> > > >
> > > >
> > > > I would like to make a Flight Recorder for my R/C helicopter. We
have
> > had
> > > > quite a few guys crash from "lockouts" and cant figure out what
> > happened.
> > > > Is this possible to do? Here is what I would like it to do:
> > > >
> > > > 1. Record all inputs to the servos and make info available to
download
> > to
> > > > PC and analyze later on
> > > >
> > > > 2. Record Radio glitches
> > > >
> > > > 3. Track battery power and show if it peaks, slumps or goes dead.
> > > >
> > > > It would be nice to see this information over a time line so you can
> > > > analyze it later ans see that a spike in battery caused a glitch,
etc.
> > Is
> > > > this possible, and can anyone help me with resources on getting
> started?
> > > >
> > > > Thanks,
> > > > Matt Johnson
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
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overwriting previous data and have it end upon a trigger from say an
impact sensor. Then you would have the previous minute or so of data to
view.
Difficult problem to isolate as I have been on the "I don't have it" end
of the transmitter as well.....
Good luck,
--
Dale Harwood [noparse][[/noparse] N4VFF ]
internet> dale@h...
ax.25> n4vff@n4vff.#cha.tn.usa.noam
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