Losing power through DS.

So we’ve come across an issue of when we’re trying to run our motors, the 5V light on the Digital Sidecar goes out and we don’t get power to the DS unless we disable-enable the Drive Station again. Drive motors 1 and 2 are in PWM slots 1 and 2. A single motor is wired into PWM 3. A Servo motor is wired into PWM 4.

PWMs 1, 2, and 3, are connected through Jaguars to CIM motors. If we unplug the PWM to the single motor (PWM 3), the issue doesn’t occur.

Also the drop in power only occurs when we push our joystick to the left. Right, Up, and Down the motors can be powered fully. We can push the joystick to the left about halfway before the power cuts.

We’ve exchanged our Digital Sidecar with two others available, and the issue still occurs. The battery is at 12.9 volts and doesn’t dip below 12.5 when we’re applying power to the motors.

We’re using the NI cRIO-FRC with modules in slots 1, 2, 3, and 5. 1:9201. 2:9403. 3:9472. 5:9201. We’ve also tried exchanging the slot 2 module, 9403, with another, issue still occurring.

Are you powering the 12V input of the Digital Sidecar off of a 20A breaker output from the Power Distribution Board? For a picture of the connector see the “Digital Sidecar Power” section on this page.

You’re describing exactly the symptoms of not having 12v power supplied to the Digital Sidecar.

Are the BAT and 6V lights lit? I’m guessing no.

You’ve guessed correctly Alan, we had just the round/flat cable that runs from the Digital Module on the cRIO. It would light up the 5V but not the other two. I’m not with the robot currently, however, so I can’t check if we’re sending power to the DS from the PDBoard or not. I’m assuming so. So silly of us to overlook this simple mistake. Tomorrow I will check and get back to the both of you.

This being said, I don’t EVER recall giving the DS power from the PDBoard. The weblink provided isn’t exactly clear to me, as I can’t tell whether or not the power to the DS is the white connector, or the two-pin cable just right of that.

Power is to be provided through the white WAGO socket. The two-pin connector is labeled RSL for the Robot Signal Light.

http://frc-labs.com/digital-sidecar-explained/ has things labeled well.

Much needed response:

To wire the light into the RSL on the DS, what connector and AWG wire should we run from the Light to the RSL 2-pin connector? Currently we’re using 18 AWG wire and there’s no connectors available to the DS-RSL pins.

You can use 2 pins of a standard 3-pin PWM connector.
Let the extra pin stick off the side, or you can trim it off with scissors.
Oddly enough one of the white wago connectors also fits.

18 AWG wire is fine. It’s actually overkill, but overkill is okay.

You can either use the two wire connector provided in the kop or use a pwmcable with the signal wire removed. Off hand I think 24 awg is required but would have to check documentation.

We were told by another team that on the DS, there is a small LED next to the 2-pin connector that flashes. On two of our three Digital Sidecars, the LED doesn’t light up. We haven’t checked the third DS, however we were also informed that it MAY be something in the coding, although I don’t see why.

If all else fails, in the previous years we’ve wired the light into the 12V terminal on the PD board. Could we splice the wires to the light and wires to the D-Link together and connect it to the same terminal?

Wired correctly, the big yellow light should blink in the same pattern as that little RSL light on the Digital Sidecar.
The RSL has absolutely nothing to do with your user coding.
The FRC image controls it.
The RSL is only active in slot 2 of the cRIO.

If all else fails, in the previous years we’ve wired the light into the 12V terminal on the PD board. Could we splice the wires to the light and wires to the D-Link together and connect it to the same terminal?

Arggg… No, no, no, no, no

The purpose of the big yellow light isn’t to be a flashlight to light the field, or find your robot in the dark.
It’s purpose is to let robot status blinks be seen at a distance across the field.

We used a multimeter to check volts coming out of the RSL 2-pin connector, and returned 0V. Also, we touched the wires straight to the 2-pins and the light still didn’t flash. We’ve tested the light itself, and it works as it should. The “green LED next to the RSL pins” as another team told us, doesn’t light up/blink.

EDIT: Also, the Big yellow light, when wired into the 12V terminal on the PD board pulsated, and wasn’t a constant on/off. It flashed in incraments.

While we’re on the DS, PWM channels 4-10 didn’t seem to function at all, sending signal to the Jaguars it was told to. In the code, we changed the PWM to 4-10 depending on which channel we were testing. Could it be possible that ALL of these channels are blown? We’ve swapped PWM cables, used other channels, and tested other Jaguars to find that everything EXCEPT the PWM channels work.

Not the right increments.
The Big yellow light will also flash incorrectly if wired incorrectly while connected to the proper RSL pins on the Digital Sidecar.

The big light m ust copy the special flash sequences of the tiny RSL on the Sidecar. There are special flashes for no code, Disabled, Autonomous, Teleop modes. If the flashes don’t match exactly, then it’s wired incorrectly.

I haven’t seen Sidecars with only a bad RSL and nothing else broken before, but new things crop up for me all the time, so I keep an open mind about it.
It could be a ribbon cable bad connection, or a short inside the Sidecar from metal dust and debris.
You could try opening up the non-working Sidecars and cleaning them out.

That sounds like it may be a problem with the Wago power connection between the Power Distribution Panel and the Digital Sidecar.

Are the three green power lights on the Sidecar all lit up a bright and glowing green?

No RSL blnk and half the PWMS are out? What are you using to connect the DSC to your cRIO? If you’re using a ribbon cable, that sounds like about half the ribbon cable isn’t crimped properly. Try a different, known good ribbon cable and/or check your current ribbon for continuity. A good ribbon cable should have continuity pin-for-pin from the male to the female side.

We do have all three signal lights, Bat, 5V, 6V, and we are using the flat cable. We DO have the rounded cable and at today’s meeting I plan on switching the flat cable to the rounded variant.

If I recall correctly, there were different weird issues with some of the round cables. I believe they centered around using the accelerometer with I2C, so that may not be a concern for you.

I heard that also, and I don’t think we’ll be using an accelerometer. However, a gyro, is still up in the air. We replaced the flat cable with the round cable, and used a brand new DS. All lights were good, and the RSL flashed/stayed constant when it was supposed to. We have yet to test the PWM channels, but I have high hopes that they will work.

I agree with the above; also check for damage and proper seating of the connector on the sidecar and digital module.

This happened to us when the cable wasn’t fully seated. One end was up only about a sixteenth of an inch, not really enough to see easily, but some PWMs stopped working.

I worked with another team who had a nick in their ribbon cable and the connection would cut out randomly. That one might sneek by a continuity check so do a visual inspection under a magnifier if you have one. Look for sharp creases as well as breaks in the insulation.

Good luck!