thought i saw smoke
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Posts: 46,084
well i hooked up a 5volt supply to my pak8 output port....oops.
was disabled, won't be using it anyway...chip still works.
these things happen. Anyway, here's the news:
pak's on another protoboard, still requires common ground between
that and stamp, chatter persists.
My ground reads 0.01V while nothing is running, (all channels
disabled, stamp paused for 5 seconds), it then enables the servos, at
which point i see a spike on ground to 0.1V.
I thought the filtered regulators would suffice, by the way, i am
filtering the regulators from their output to ground, before i had it
across the inputs, which is better? I assum the way it is now as
before ground was a constant 0.06V, would that observation be correct?
If a seperate battery pack doesn't cure the chatter..i'm fresh out of
ideas. I will try that next, only makes sense with what i've
seen ..and been told. Assuming this will cure the chatter, here's my
new problem:
I'm using high discharge SCR remote control car batteries, made the
pack myself. My reasoning for doing this is the robot must be
optimised and that will require alot of testing/changing
variables/more testing..these cells can be charged several times in a
short period of time with no damage, and it only takes four minutes
for a complete charge, allowing for alot of testing. Anyway, the maze
is small and i don't have the space for a second battery pack to
power the servos. Servos are also plastic gears and it's alot of
added weight. Is there any way this could be solved allowing me to
keep just one battery pack to run it all?
was disabled, won't be using it anyway...chip still works.
these things happen. Anyway, here's the news:
pak's on another protoboard, still requires common ground between
that and stamp, chatter persists.
My ground reads 0.01V while nothing is running, (all channels
disabled, stamp paused for 5 seconds), it then enables the servos, at
which point i see a spike on ground to 0.1V.
I thought the filtered regulators would suffice, by the way, i am
filtering the regulators from their output to ground, before i had it
across the inputs, which is better? I assum the way it is now as
before ground was a constant 0.06V, would that observation be correct?
If a seperate battery pack doesn't cure the chatter..i'm fresh out of
ideas. I will try that next, only makes sense with what i've
seen ..and been told. Assuming this will cure the chatter, here's my
new problem:
I'm using high discharge SCR remote control car batteries, made the
pack myself. My reasoning for doing this is the robot must be
optimised and that will require alot of testing/changing
variables/more testing..these cells can be charged several times in a
short period of time with no damage, and it only takes four minutes
for a complete charge, allowing for alot of testing. Anyway, the maze
is small and i don't have the space for a second battery pack to
power the servos. Servos are also plastic gears and it's alot of
added weight. Is there any way this could be solved allowing me to
keep just one battery pack to run it all?
Comments
batteries, and i also found a ground loop, took care
of that.
Still seems to chatter somewhat, shouldn't a schmitt
trigger not operate as straight on or off? it seems to
mirror the detectors output for the most part. I
expected to see 0V to a quick transition of 5V. I took
loading into effect but..there must be something I had
missed. the best i had it working last night by
playing with resistor values...finally had it
switching as i though it should have..touching an VOM
probe to the detectors output loaded it right down and
it would stop working. Anyway it still chatters
somewhat, any hysteresis recommendations for the type
of detecor i'm using?
______________________________________________________________________
Web-hosting solutions for home and business! http://website.yahoo.ca
noise feedback from the motors or the PAK, I'd guess the detector is
oscillating. If it is swinging from 0 to 5V the Schmitt trigger won't
magically clear that up. A low pass filter might clear it up, but that
seems like cheating.
Al Williams
AWC
* Easy RS-232 Prototyping
http://www.al-williams.com/awce/rs1.htm
>
Original Message
> From: c bielek [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=G9bKxEgeZxieCnDDrF5xN8pKjUp10bjNjptrGSqU3Awo6COCL7MrHmDeOxCcgynJhxchoINz9fY]cbielek@y...[/url
> Sent: Wednesday, January 23, 2002 8:02 AM
> To: basicstamps@yahoogroups.com
> Subject: Re: [noparse][[/noparse]basicstamps] thought i saw smoke
>
>
>
> It does seem to work a little bit better with two
> batteries, and i also found a ground loop, took care
> of that.
>
> Still seems to chatter somewhat, shouldn't a schmitt
> trigger not operate as straight on or off? it seems to
> mirror the detectors output for the most part. I
> expected to see 0V to a quick transition of 5V. I took loading into
> effect but..there must be something I had missed. the best i had it
> working last night by playing with resistor values...finally had it
> switching as i though it should have..touching an VOM
> probe to the detectors output loaded it right down and
> it would stop working. Anyway it still chatters
> somewhat, any hysteresis recommendations for the type
> of detecor i'm using?
>
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