We Need Serious Robot Help!

[alexander.h]

Our robot doesn't drive at all! I'd give more details, but there are too many to list! Ask me any question you want that could help you understand what is wrong with our robot! We're in the workshop right now, so we can try anything now on our robot that could help it roll! Please help us!

[geomapguy]

Our robot doesn't drive at all! I'd give more details, but there are too many to list! Ask me any question you want that could help you understand what is wrong with our robot! We're in the workshop right now, so we can try anything now on our robot that could help it roll! Please help us!

Programming language?? post code

Post picture of wiring

[BigJ]

You should probably list your setup, the things you've tried, and the exact problems you are currently running into (more specific than "It won't drive!!!").

[AdamHeard]

Pictures are good too.

[E Dawg]

What color are the lights on your motors?

Have you reimaged your cRIO this year?

Is everything correctly wired into the PD board?

Does the driver station indicate that you are connected to your robot?

[alexander.h]

Programming language?? post code

Post picture of wiring

We program in Labview. I attached pictures from the three VIs, but I'm not able to give you pictures of the wiring.

[cgmv123]

What motor controllers are you using?

Is the PWM seated in all of them properly.

Does your drivetrain spin fairly easily without the motors?

Is your digital sidecar properly powered?

Are your motors trying to fight each other in the gearbox?

[alexander.h]

What color are the lights on your motors?

Have you reimaged your cRIO this year?

Is everything correctly wired into the PD board?

Does the driver station indicate that you are connected to your robot?

The colors on the Talons are the same (orange), but two flash and two are solid. No, we haven't reimaged our cRIO this year. Everything is corretly wired on the PD board. The driver station says that we are connected to the robot. Anymore questions?

[E Dawg]

In the first VI your "Open 2 Motor" VIs are set to rely on a single PWM. That might not be the only problem, but it could cause issues later on.

[alexander.h]

What motor controllers are you using?

Is the PWM seated in all of them properly.

Does your drivetrain spin fairly easily without the motors?

Is your digital sidecar properly powered?

Are your motors trying to fight each other in the gearbox?

The PWMs are properly seated. We can still turn the drivetrain by ourselves. How can we tell if the DSC is properly powered (only 2 out of 3 LEDs are on). No, our motors aren't fighting against each other. Does that help?

[Bryce2471]

when you press forward on the joystick(s) what does your robot do?

[Joe Ross]

The PWMs are properly seated. We can still turn the drivetrain by ourselves. How can we tell if the DSC is properly powered (only 2 out of 3 LEDs are on). No, our motors aren't fighting against each other. Does that help?

I told you how to in your 2nd thread.

I suspect that both this problem, and your previous talon problem both have the same root cause, not properly powering the Digital Sidecar.

Remove the DB-37 cable from the digital sidecar and verify that all 3 power LEDs on the Digital Sidecar are brightly lit. If they aren't, make sure the digital sidecar is powered from a 20amp circuit from the PDB.

By creating 3 different threads, and not following the advice in previous threads, you're making it harder to help and take longer to get to the root cause.

[alexander.h]

In the first VI your "Open 2 Motor" VIs are set to rely on a single PWM. That might not be the only problem, but it could cause issues later on.

It's because, physically, they are. Go to http://wpilib.screenstepslive.com/s/3120/m/8559/l/92626-wiring-the-2014-frc-control-system and do a ctrl+f to search for "4 Controllers - PWM Cables".

[alexander.h]

when you press forward on the joystick(s) what does your robot do?

Nothing. Absolutely nothing.

[alexander.h]

I told you how to in your 2nd thread.



By creating 3 different threads, and not following the advice in previous threads, you're making it harder to help and take longer to get to the root cause.

I followed your advice, but it still doesn't work.

[IronBenderII]

Alexander. We can probably assist you tonight, maybe Skype or Face Time. I will send you a PM with my contact information...

[E Dawg]

It's because, physically, they are. Go to http://wpilib.screenstepslive.com/s/3120/m/8559/l/92626-wiring-the-2014-frc-control-system and do a ctrl+f to search for "4 Controllers - PWM Cables".
Sorry. I'm used to running a tank drive with four different PWM cables.

If you have anything that you can test power output with, try it on the motor controllers and post it here. That may help us to narrow down possible causes for your problem.

[alexander.h]

Sorry. I'm used to running a tank drive with four different PWM cables.

If you have anything that you can test power output with, try it on the motor controllers and post it here. That may help us to narrow down possible causes for your problem.

On the red plus sign of the talon, there's 11 volts. On the other side, it's 0 volts.

[Bryce2471]

Does your joystick show up on the driver station?
If it does, is it in the right slot/configuration?

[Tem1514 Mentor]

The PWMs are properly seated. We can still turn the drivetrain by ourselves. How can we tell if the DSC is properly powered (only 2 out of 3 LEDs are on). No, our motors aren't fighting against each other. Does that help?

If don't have all three LED's lighted on the digital sidecar none of your drive motors will work.

So go back to basics and check your wiring. The first place to start is with the digital sidecar and make sure are supplying 12 Volts NOT 5 volts to it. You get
12 volts from a 20 amp breaker on the PDB. Start with that and go forward one step at a time.

[cgmv123]

The colors on the Talons are the same (orange), but two flash and two are solid.

Which 2 are solid? Are they on the same side or different sides?

Flashing orange means the Talon isn't getting any signal. Solid orange means the Talon is getting a signal, but it won't output anything since that signal is 0.

If it's flashing, it could be a code issue or a wiring issue. If it's solid, it's most likely a code issue, since the code has to be the one to send the Talon a signal of 0.

On the red plus sign of the talon, there's 11 volts. On the other side, it's 0 volts.

I don't think this is the issue, but replace your battery with a fully charged one just to be sure.

[Chris_Ely]

Check your wiring.
All power should be wired according to this (http://www.usfirst.org/sites/default/files/uploadedImages/Robotics_Programs/FRC/Game_and_Season__Info/2014/ElectricalLayout.pdf) diagram.
All data (PWM, camera, and sensors) should be wired according to this (http://www.usfirst.org/sites/default/files/uploadedImages/Robotics_Programs/FRC/Game_and_Season__Info/2014/SignalLayout.pdf) diagram.

[chris.boyle]

I suspect that since you opened two instances of the drive system, they were competing with each other.

I'm enclosing a VI that shows how we opened our Joystick and the Archade Drive System using 4 motors. The code only identifies a 2 motor drive system, the "Y" cable from PWM1 goes to both motor controllers on the left side and the "Y" cable from PWM2 goes to both motor controllers on the right side. All motor control's MUST be of the same type; ie: Talon, Victor, Jaguar.

[AGPapa]

I suspect that since you opened two instances of the drive system, they were competing with each other.


This is almost certainly the problem.

You only need to have one drive system, the default arcade drive code works fine for your application and did not need to be changed.

I've attached a photo if you don't want to download Chris's code.

[Joe Ross]

I followed your advice, but it still doesn't work.

What did you do? When you removed the DB-37 cable, which power LEDs (if any were still lit). List them by name. How did you verify power to a 20 amp breaker on the PDB? Find a mentor who is proficient with a multi-meter to verify 12 volts at the Digital Sidecar power connector.

Your programming is also wrong, as pointed out by other people. However, do not ignore the power LEDs on the Digital Sidecar, even if the software changes "fix" your immediate problem. You need to get the Digital sidecar power fixed or else you will have more problems down the road.

[John]

This is almost certainly the problem.

You only need to have one drive system, the default arcade drive code works fine for your application and did not need to be changed.

I've attached a photo if you don't want to download Chris's code.

The code is the a problem. You are commanding the same motor to go forward and reverse at once, making it not move.

This is actually not a direct result of using two drive systems (they cannot fight each other, drive one only uses PWM 1 and drive two PWM 2). The problem is because you have configured the left and right motors on each drive to feed to the same PWM, and then inverted one of them.

So your code works like this (when you go forward).
-->Get joystick value (1)
-->Set leftmotor to inverted joystick value (-1)
-->Set rightmotor to noninverted joystick value (1)
-->Left motor is PWM 1, set PWM 1 to value of -1
-->Right motor is PWM 1, set PWM 1 to value of 1

Nothing ever happens because you make the motors go full forward and full backward as fast as the code can execute.

Use Chris's code, but modify it for 4 talons (or use y-cables)

[alexander.h]

Does your joystick show up on the driver station?
If it does, is it in the right slot/configuration?

Yes and yes again.

[alexander.h]

If don't have all three LED's lighted on the digital sidecar none of your drive motors will work.

So go back to basics and check your wiring. The first place to start is with the digital sidecar and make sure are supplying 12 Volts NOT 5 volts to it. You get
12 volts from a 20 amp breaker on the PDB. Start with that and go forward one step at a time.

Thanks, all three are on now, but what do i do next?

[alexander.h]

Which 2 are solid? Are they on the same side or different sides?

Flashing orange means the Talon isn't getting any signal. Solid orange means the Talon is getting a signal, but it won't output anything since that signal is 0.

If it's flashing, it could be a code issue or a wiring issue. If it's solid, it's most likely a code issue, since the code has to be the one to send the Talon a signal of 0.



I don't think this is the issue, but replace your battery with a fully charged one just to be sure.

My bad, all three are now and changing the battery doesn't work either.

[magnets]

We really need pictures to help you. Somebody on your team must have an iphone with camera who would be willing to take a picture for you.

Anyway, the flashing orange light on the talon means the talon has power, but no signal. If you're using the code posted earlier, which is correct, and you followed joe's advice to remove all cables but the power one and confirmed that all three leds are lit, then you need to check your pwm cable. Is it plugged in the right way? Try flipping the connector. Is it plugged in all the way?

The solid orange light means that your code is wrong (make sure you copy what was posted) or your driver station isn't recognizing your joystick. Under the diagnostic tabs, what color does the joystick 1 indicator turn when you push a button?

[Greg McKaskle]

If you believe the electronics are in better shape, lets talk about how to debug SW.

If you go to RobotMain and press the run button, the code will download and start running. At that point you can open TeleOp and other subVIs and see values on their panels. You can open their diagrams and right-click to probe wire values.

So, after you are running your code, go to the Driver Station and Enable the robot for TeleOp mode. Open the TeleOp VI and determine if the joystick is making it to the robot and tracks physical joystick input values. If so, move to the Robot Drive code. It actually returns the values that it sent to the motors and by default those were being written to the SmartDashboard so that your could see what the SW was sending. Since that code has been deleted, you may want to wire it to indicators. Right click on the outputs and create indicators.

Determine if the SW is sending useful values to the motor controllers.

If you aren't making progress, you may want to open an example, set the PWM values and verify your electronics with that. You may also want to create a new robot project, set your PWM values in Begin, but don't delete and decorate the code so much until you know that it works.

Greg McKaskle