Chief Delphi - Problem with old bot

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Re: Problem with old bot

Quote:

Originally Posted by Greg McKaskle (Post 1094104)

I'd start with the SW or HW split. If you have diagnostic errors due to watchdog timeouts or other configuration issues, fix those first. If the SW is not producing any errors, trace the pwm values to see if the SW is setting them to zero.

From there, if the SW is setting the correct values, but the SW isn't responding, you can isolate the speed controller, digital sidecar, and digital module.

Greg McKaskle

we did do a decent amount of software testing and a little of electrical.
We printed out voltages and wheel speed ratio (-1 to 1) values and then tested voltages on each victors. they all turned out to be pretty accurate
not sure what you mean by the "setting them to zero part"

Quote:

Originally Posted by PAR_WIG1350 (Post 1094101)

You put a multimeter to the frame and what? If both probes were on the frame, the resistance would be 0.0, or close to 0.0, as would the voltage (due to the fact that the resistance is 0). The proper way to test for electrical continuity problems is to , with the meter set to measure in kOhms, place one probe on the frame while the other one is placed on the cRIO chassis, the back of the axis camera, motor controller outputs, and the PD board inputs (Make sure the robot is off, or preferably, the battery is out of the robot. ). If the meter displays infinity (usually a 1 at the far left of the display) in all cases described above, but 0.0 when the probes make contact with each other, then the electrical system is likely not shorted to the frame.

I apologize, it was volts. I had no idea ohms would also play a factor
and as for how we did it, the way I was taught was by putting the positive on the frame and the negative on a ground port (the V- on a victor to be exact).
I will check the other things you've said once we get off of break

Quote:

Originally Posted by jgw (Post 1094071)

Would that be a reading of 0.0 ohms = bad or 0.0 volts = good? A value without units is meaningless.

Sorry about that. It was 0.0 volts

Re: Problem with old bot

King,
We should have mentioned that you must have a good power supply to the digital sidecar. Teams are often confused when they see a few lights on the sidecar and think it has power. There should be three LEDs indicating good power coming in, a solid 5 volts and six volts from internal supply/regulators. Finally, a solid LED next to the robot signal light connector indicates that the robot is enabled.

Re: Problem with old bot

Quote:

Originally Posted by Al Skierkiewicz (Post 1094143)

Al, If the DS power supply was intermittent (it obviously can't be missing, since the Victors do operate) how would that generate the problem?

Another problem that you may be having is Victor failure - and yes, Victors do fail, however much I'd hate to admit it. Of course, as mentioned earlier, it could also be a programming problem. First, watch the Victor LEDs. One side should be turning green and the other should be turning red while going forwards (if this isn't the case, then testing the lights will be ineffective), and while attempting to go backwards, you should see a color reversal - one side red, the other side green.

If that color reversal does not happen, then the problem falls into one of two cases. One - if the colors both turn to solid yellow, then you've most likely got a programming problem, because that means the backwards drive command isn't getting to the Victors, although it is possible to have an electrical problem. Two - if the colors go out, either it has been calibrated incorrectly (pull up the Victor datasheet to see what I'm talking about) or the signal going to the Victor has been changed, either in programming or through a short.

If the color reversal does happen, then it's possible the problem lies within the Victor itself. Turn off the robot and reverse the motor leads on each Victor (i.e. in each Victor-motor connection, swap the red and black motor leads on the Victor). This will electrically flip your controls, so that driving forward will move you backward, and vice versa. If you can't move forward, then the problem - as absurd as it may seem - is most likely your Victor itself, because it confirms that your motors are capable of driving the robot backward, and that the Victor is receiving the signal, but not transferring it to the drive motors.

Also, I'd advise turning the robot off and checking with resistance to measure continuity. I've never been a fan of playing with a live robot, especially one with a short.

Re: Problem with old bot

Quote:

Originally Posted by slijin (Post 1094150)

Al, If the DS power supply was intermittent (it obviously can't be missing, since the Victors do operate) how would that generate the problem?

If the Digital Sidecar 12VDC power input is missing, the Victors can indeed still work. There's enough leakage from the 37-pin connection to the cRIO to give the appearance of things functioning. But as soon as you tell enough of the PWM signals to go "reverse", the average voltage drops and things can quit.

I'm out of practice. Based on the clues in the initial description, checking the DS power should have been my first suggestion. Measure the power input on the white Wago connector and verify that it's getting battery voltage. Make sure that that BAT, 6V, and 5V LEDs are all fully lit.

Re: Problem with old bot

Quote:

Originally Posted by slijin (Post 1094150)

Two - if the colors go out, either it has been calibrated incorrectly (pull up the Victor datasheet to see what I'm talking about) or the signal going to the Victor has been changed, either in programming or through a short.

The colors go out when going in full reverse so yeah. I'll double check the programming whenever I have access to the computer but we have checked it a few times and I have no clue what else it could be. We even tried disabling motor safety(risky I know) and there was no change in what happened. I'll double check for shorts and also the Digital Sidecar like Al said. If only it were convenient enough that things lighting up meant they were working lol.

Re: Problem with old bot

we have been having trouble with our robot not moving at all after i put a code on it. the orange signal lights do not even come on even though the wires leading to them are perfectly fine. drive station says everything is running but no motion or anything. compressor wont start. i did hit the format option when imaging crio after every time i switched the safe mode swich it said in safe mode and wouldnt image the crio. after formating it, it did image and i finaly got code on. but now the problem of nothing working at all. any help or information would be greatly appreciated.

Re: Problem with old bot

We had some issues with the Slot #'s for the modules now being 0 indexing instead of 1. This might help someone here.

Re: Problem with old bot

Quote:

Originally Posted by MagiChau (Post 1103939)

We had some issues with the Slot #'s for the modules now being 0 indexing instead of 1. This might help someone here.

What do you mean?

The slot numbers aren't relevant to the code. The first module of each type is module 1; the second is module 2. If you only have one analog, one digital, and one solenoid module, they're all number 1.