measuring AMPs / avoid PTC trip

I need to monitor the amps being pulled while driving to see which modifications will help me reduce the likelihood of stalling my motors. I do not see this in the RobotC UI. Can you tell me easiest way to see/measure this real time?

There is no sensor built into the cortex that can measure current draw of specific motors.

Have you looked at jpearman’s smart motor library?

I was just at the US Create Open in Iowa and the very helpful VEX rep was able to monitor our robot and show me the amperage spikes real time. Our robot appears to have issue with (presumable new) very squishy fields. Since I cannot reproduce this issue on any other mat, I was trying to see if I could at least measure the compare the amp draw using different wheels/configuration or other modifications. I neglected to ask what software he was using.

I have also looked this reference but the link appear to be dead

Hmm, I’d be interested to know how they did this exactly. I believe it is possible to measure the total current draw from the battery, but am not sure how.

The links from 2012 are dead, I moved the library to github in 2013.

There is no built in current monitoring inside the cortex, the only way to monitor actual current is to use external components, one example is in this thread.


Thank you for your reply. I will review and try to apply the library. We have a 6 motor tank drive. Each side has one encoder with both wheels (and all 3 motors tied mechanically tied together). The drive performs very well forward and reverse but can be stalled after repeated turning (like doing donuts). However, we are having issues on extremely soft mats while when even just moderate repeated turning is necessary (like to move away from a wall). If this can keep us from stalling it will be a lifesaver. Thank you.

What wheels are you using? Anything more than one regular wheel on each side causes tons of friction when turning, which is why it’s good to use omni wheels.

Much appreciated…This is one of the configurations we were wanting to test. Currently we have 4 traction wheels which is somewhat integral to our lift process, but we can probably work around that. My hope was to measure the load reduction under different wheel configurations since I don’t have any new/soft mats or a lot of time to test.