D
David Geesaman
- Jan 1, 1970
- 0
I'm thinking about making a laptop-based DAQ system for monitoring the
behavior of some systems on my car. The point is to monitor and log a few
values at once while keeping my eye on the road. I suspect the ECUs on this
car get flaky, and I'd love to trace down the source of the problem. I
think I'll lose interest if this project costs me more than $200 total.
This requires:
- sensing absolute pressure from 0 to 3 Bar.
- 3-5% accuracy would be fine. I won't need to log many hours with this
thing running, either.
- sensing voltages (DC and duty-cycle signals) from the ECU pinouts, 0-15v,
with a max rate of about 1kHz. (Hence, 2-5kS/s sampling, which isn't asking
much these days). Duty cycle output frequencies are on the order of 1kHz.
- total of 2-3 pressure sensors and 2-3 voltage sensors, with a minimum of 3
at once. Of course more would be better.
- interface to the cheap laptop, preferably with no programming and
additional software needed. I see many USB devices, and though the laptop
is really old (Pentium 200MHz), I can get a PCMCIA USB card for $12.
I found a nice DAQ unit
http://www.hytekautomation.com/Products/IUSBDAQ.html which leaves $100 for
buying sensors.
1) The DAQ units I see are 0-4V and -10 to 10V. I will be reading a range
of 0-15v. What's the best way to handle this?
2) What kind of sensors should I get, and how will I power them? (of
course, I have 12v available). I could probably buy some old MAP sensors
from the junkyard, or is there are cleaner way?
3) Any other tips? I'm a mechanical engineer, so the cheapest/easiest way
to logging my values is what I value most.
Thanks for any advice,
Dave
behavior of some systems on my car. The point is to monitor and log a few
values at once while keeping my eye on the road. I suspect the ECUs on this
car get flaky, and I'd love to trace down the source of the problem. I
think I'll lose interest if this project costs me more than $200 total.
This requires:
- sensing absolute pressure from 0 to 3 Bar.
- 3-5% accuracy would be fine. I won't need to log many hours with this
thing running, either.
- sensing voltages (DC and duty-cycle signals) from the ECU pinouts, 0-15v,
with a max rate of about 1kHz. (Hence, 2-5kS/s sampling, which isn't asking
much these days). Duty cycle output frequencies are on the order of 1kHz.
- total of 2-3 pressure sensors and 2-3 voltage sensors, with a minimum of 3
at once. Of course more would be better.
- interface to the cheap laptop, preferably with no programming and
additional software needed. I see many USB devices, and though the laptop
is really old (Pentium 200MHz), I can get a PCMCIA USB card for $12.
I found a nice DAQ unit
http://www.hytekautomation.com/Products/IUSBDAQ.html which leaves $100 for
buying sensors.
1) The DAQ units I see are 0-4V and -10 to 10V. I will be reading a range
of 0-15v. What's the best way to handle this?
2) What kind of sensors should I get, and how will I power them? (of
course, I have 12v available). I could probably buy some old MAP sensors
from the junkyard, or is there are cleaner way?
3) Any other tips? I'm a mechanical engineer, so the cheapest/easiest way
to logging my values is what I value most.
Thanks for any advice,
Dave