Data Acquisition
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Posts: 46,084
I do not own a Basic Stamp yet, but I am wondering if it can do what
I want before I go to the expense of buying one. I looked back
through the messages here and didn't see anything like this.
I would like to build a data acquisition system for my RC truck. Sort
of a real time dyno. I am looking to monitor the following: battery
voltage, current draw, battery temperature, motor temperature and rpm
in the beginning. Then maybe later add on G forces, servo positions
and who knows what else if the first part would work.
I figure I only need to collect data 4 times a second for 6 minutes.
Figuring 5 sets of data 4 times a second for 6 minutes means 7200
data points. Once done the data could be transferred to a PC of
plotting.
So I guess what I want to know is if this is possible with the BS?
Open to ideas, recommendations and input.
I want before I go to the expense of buying one. I looked back
through the messages here and didn't see anything like this.
I would like to build a data acquisition system for my RC truck. Sort
of a real time dyno. I am looking to monitor the following: battery
voltage, current draw, battery temperature, motor temperature and rpm
in the beginning. Then maybe later add on G forces, servo positions
and who knows what else if the first part would work.
I figure I only need to collect data 4 times a second for 6 minutes.
Figuring 5 sets of data 4 times a second for 6 minutes means 7200
data points. Once done the data could be transferred to a PC of
plotting.
So I guess what I want to know is if this is possible with the BS?
Open to ideas, recommendations and input.
Comments
First, it appears you want to collect a huge number of data all of which have
to be stored in variables. Stamp does not have this room for this many
variables so you have to work around it. With Stamp it is possible to read
the five variables you want, capture the readings in Hyperterminal, then get
more data using the same variables. This way you can get an infinite amount
of data. If you capture the data to Excel, you can graph it with a mouse
click. If you decide to go ahead with the project, stay in touch and I will
show you how to set up a data reading program that uses the same variables
over and over.
Sid
Hummm... I didn't figure that 2700 data points was a lot of data and
that BS didn't have at least that much storage. Using Hyperterm is
not an option because the truck will not be connected to a computer
as it runs around a track. Hummmm.... maybe I'm barking up the wrong
tree here in looking at BS for what I want to do.
for that. The problem is you have to assign avariable name to the five
parameters you want to read. If you read them once and capture the data then
you can re-use the variables. If you don't read and capture then you have to
have a new variable for each parameter each time you read it, and that makes
for a huge number of variables. It appears tht your solution would be to use
an inexpensive RF Link like the TWS/RWS from Rentron, send the data to
another stamp connected to your PC and capture the data that way.
Sid
Sid
Alternatively you could read each parameter, add it to a "sample"
accumulator, then an the end of six mminutes compute the average of all your
readings. That would only take 10 variable. You would have to make sure
that the total sum of any one variable did not exceed 65500 because that is
a 16-bit variable and the largest that Stamp can store in a variable.
Sid
same 5 or 10 var, as long as he writes to eeprom after each read of all.
Original Message
From: <Newzed@a...>
To: <basicstamps@yahoogroups.com>
Sent: December 09, 2001 12:51 PM
Subject: Re: [noparse][[/noparse]basicstamps] Re: Data Acquisition
| For Hank
|
| Alternatively you could read each parameter, add it to a "sample"
| accumulator, then an the end of six mminutes compute the average of all
your
| readings. That would only take 10 variable. You would have to make sure
| that the total sum of any one variable did not exceed 65500 because that
is
| a 16-bit variable and the largest that Stamp can store in a variable.
|
| Sid
|
| To UNSUBSCRIBE, just send mail to:
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| from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
|
|
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|
|
Don't know - he is going to be reading 7200 words of data. Don't think the
Stamp storage is large enough to hold a program to write that many separate
variables to EEPROM.
Sid
OK, I understand better. While it still seems that having that few
varibles is still pretty limiting. The RF option does seems
interesting, I'll have to look at the specs for them.
not need words but bytes
bat voltage one byte
current draw one byte
bat temp one byte
motor temp one byte
rpm one byte
g fource one byte
servo pos one byte
so 7 bytes per reading X 4 readings per second = 28 bytes per second x 60
seconds = 1680 per minute x 6 minutes 10080 bytes total so a 128 kbit eeprom
= 16000 bytes there will be some waited space because of page write you will
need to write 8 bytes per writing to keep the pages even, but you still only
use 11520 kbytes now the speed is another matter you could look up some of
Tracy Allen's timing for commands . I hope this is correct ?
Original Message
From: <Newzed@a...>
To: <basicstamps@yahoogroups.com>
Sent: December 09, 2001 1:31 PM
Subject: Re: [noparse][[/noparse]basicstamps] Re: Data Acquisition
| For Iga
|
| Don't know - he is going to be reading 7200 words of data. Don't think
the
| Stamp storage is large enough to hold a program to write that many
separate
| variables to EEPROM.
|
| Sid
|
| 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/
|
|
Goto www.rentron.com
Using an RF link would let you read and acquire the data for 60 minutes if
your truck would run that long!!
Let me know if I can help. I have and am using the TWS/RWS modules.
Sid
>I want before I go to the expense of buying one. I looked back
>through the messages here and didn't see anything like this.
>
>I would like to build a data acquisition system for my RC truck. Sort
>of a real time dyno. I am looking to monitor the following: battery
>voltage, current draw, battery temperature, motor temperature and rpm
>in the beginning. Then maybe later add on G forces, servo positions
>and who knows what else if the first part would work.
>
>I figure I only need to collect data 4 times a second for 6 minutes.
>Figuring 5 sets of data 4 times a second for 6 minutes means 7200
>data points. Once done the data could be transferred to a PC of
>plotting.
>
>So I guess what I want to know is if this is possible with the BS?
>Open to ideas, recommendations and input.
You could do that with a BS2e or a BS2p, which have 16kbytes of
eeprom for storage of program or data. (The programming is easiest
on a BS2p because of an extra command that it has.) I have a note
on a small data logger using the multibank stamps posted at
http://www.emesystems.com/BS2SX.htm#datalogger
Or you could do it with an ordinary BS2 and use external eeprom to
store the data. If you want a superb tutorial on how to build a BS2
data logger using an external eeprom, you can't beat Scott Edwards'
manual for the (now discontinued) Data Collection Proto Board. Scott
still has the manual on line for free download at:
http://www.seetron.com/pdf/dcpb_mnl.pdf
Newzed's suggestion of a radio link to hypercard would of course give
you immense storage options!
bs2p and use a couple of pages for data storage, then serout the data to
your pc when you have finished. The stamp would be perfect for this. There
are plenty of examples around for shifting data into and out of eeproms.
Regards,
Chris
Original Message
From: Newzed@a... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=yNVx6la3diNrbHGZeDMspLnLo_pv3pi0OHPdsEmzOp_zfn3Bz0AIijt4sJpxDKfzKI0KI8M]Newzed@a...[/url
Sent: Monday, 10 December 2001 4:44 AM
To: basicstamps@yahoogroups.com
Subject: Re: [noparse][[/noparse]basicstamps] Re: Data Acquisition
It isn't the data stoarge that is a problem, Hank - there is plenty of room
for that. The problem is you have to assign avariable name to the five
parameters you want to read. If you read them once and capture the data
then
you can re-use the variables. If you don't read and capture then you have
to
have a new variable for each parameter each time you read it, and that makes
for a huge number of variables. It appears tht your solution would be to
use
an inexpensive RF Link like the TWS/RWS from Rentron, send the data to
another stamp connected to your PC and capture the data that way.
Sid
Sid
To UNSUBSCRIBE, just send mail to:
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but never implmented a protocol. What do your packets look like? Did you
implement 2-way communications?
Thanks,
Kevin
Newzed@a... wrote:
>
> For Hank
>
> Goto www.rentron.com
>
> Using an RF link would let you read and acquire the data for 60 minutes if
> your truck would run that long!!
>
> Let me know if I can help. I have and am using the TWS/RWS modules.
>
> Sid
>
> 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/