i was wondering if there was a sensor out there that we could use to find the pressure of our pneumatics and take that pressure and make it available for use in the code. if you know of one that is relatively cheap and works decently it would be much appreciated. thanks in advance
Well, there is one. IIRC, it’s included in the KOP. It’s definitely required if you’re going to use pneumatics (<R72> in the 2011 rules). It goes into the code, and if the pressure is too low, the compressor turns on.
If you need something more than that, you can refer to the same sensor. Note that it is on the high-pressure side of the circuit, so you may also want one for the low-pressure side, but that’s your choice (and you could reasonably expect a more detailed inspection due to having two sensors–which one really runs the compressor and all that sort of thing).
This isn’t entirely correct. They include a pressure switch not a pressure transducer. Supposedly TI donated one a number of years ago, but I have yet to find it.
I am also very interest in the answer to this question.
Thanks
We have a TI pressure transducer from 04, if I am correct. The voltage is proportional to the pressure.
According to this post, the model number is TI 5CP3-7.
analog pressure sensors -they do exist… Actually, my old team (2783) had one for the 2010 bot that was never installed, and as part of my restoration project, I connected it tot he low (60psi) side of the air circuit. IIRC, it was a $50 part.
be careful, as this sensor was only rated for 100 PSI, the original intended use was on the high side, which would have killed it.
electrically, it used a 12v input. it had an output of 0-5v, with 5v=100 PSI.
pnumatically, it was put right after the output of the 60 PSI regulator
Code wise, IIRC (it has been a while since I re-wrote the code), it first multiplied the voltage by 20 to render the PSI, then I used that number to disable the kicker (only thing pnuematic) if the PSI was over 65 or below 40, as low pressures would jam the solenoids. the actual pressure and over/under data was sent to the dashboard, where the pressure had both a gauge and actual readout. The over/under pressure signals were routed to colored lights on the dash (over red, under green).
I attached the labview source code for the dash and robot (and the dash .exe) for those who want a look at the implementation.
berk.zip (670 KB)
berk.zip (670 KB)
We have used an SMC one in the past that has an ANALOG output. So we could scale the PSI in the code. It also had a nice digital read out.
http://www.smcetech.com/CC_host/pages/custom/templates/smc_v2/prodtree_branch_group_2.cfm?cc_tvl=&cc_nvl=((CC,smc,INS_US,Node_22836))&CFID=887930&CFTOKEN=64578773&jsessionid=84308cb7ae1b03df21f2698065c156a221d4
In 2007, air was really important for us.
Team 1073 has used SSI 5V (0.5 to 4.5V output) analog pressure transducers.
Digikey has a good selection in the $68 range.
I think we used the 300 psi rated part, just to avoid any argument with the inspectors. This reduced our accuracy in the 0 to 60 PSI range we were working with, but it wasn’t a problem for our application.
FYI
Texas Instruments no longer owns that company. If you want to buy that part you have order it through Sensata Inc.
The make a variety of pressure tranducers from 0-10 Volt ratiometric output.
I’ve used them at work over the years.