Digital Sidecar Problems

[cabbagekid2]

Hey Guys I think something is definitely wrong with both of our digital sidecars but wanted to get ur opinion.

We couldn't get our programs to work for three days with Labview. The example programs didn't even work! They downloaded by all the victor and jaguars had no signal. Turns out, after we removed the jumper next to the pwm pin for the servo, things magically started working. So we got everything to work except for the servos (since we can't connect the jumper else everything will not work). The watchdog timer light didn't turn on so it's not a software issues (especially since it works if we remove the jumper using the same program).

We also noticed through our trouble shooting that the BAT and 6V lights on the digital sidecar do not light up. Are they suppose to? Is the 6V suppose to light up with the jumpers (it doesn't)? But the 5V light is on.

Are both of our digital sidecars defective? Anyone else have this problem?

[Mark McLeod]

Do you have the Digital Sidecar wired from the 12v waqo connector directly to the Power Distribution panel, with an associated 20A breaker?

How about if you take a close up photo of the Digital Sidecar all wired up and post it for us?

[cabbagekid2]

We're not going to be going in to the shop today so I'll have to post a picture tomorrow, but I can describe how things are wired to the digital sidecar.

18AWG, 12V from wago connector connected to 20A breaker on power distribution pannel.

DB37 Cable from cRIO to digital sidecar.

Pwm 1 & 2 connected to jaguar
Pwm 3 & 4 connected to victor
Pwm 5 connected to servo, jumper installed (also tried Pwm 8 and 10 same resuts)

Pwm installed according to pinouts as shown on digital sidecar.

Thanks for the help!

(Also posted on FIRST forums in case we actually do need a replacement and it's not a solvable problem)

[Mark McLeod]

The connections sound correct.

It's very strange though that you'd happen to get both defective Digital sidecars.

With the lack of Batt and 5v status leds I'd suspect the 12v power feed from the distribution panel.
When you tried both side cars did you use the same power cable?

An immediate suspect is that the wago clamps at one end or the other are grabing insulation rather than wire.
Try pulling the 20a breaker (leaving the power distribution wago connections alone) and testing continuity of that cable with a meter.

After testing try removing the wire from both wago connector ends and reattaching them.

[cabbagekid2]

Yup, both sidecars having the same problem seems wierd unless it's a manufaturer defect. But then I would expect more teams to have the same problem (we got ours as part of the early ship-early dec).

When we did try the two we used the same power connection. We'll try a different breaker/wire and see what happens.

What's strange is that when we take out the jumper, the Bat light still stays off (5V on) but everything still works.

[Mark McLeod]

The PWMs for the speed controllers don't use the 12v power. That's just for the servos, digital I/O's, relays, I2C.
So it's not surprising that they work without the power line. The DB37 must feed enough power for the basic sidecar circuitry.

It is interesting that the jumper stops them from working. I'll try pulling the plug on ours tonight and seeing if we get the same behavior with a jumper.

[Russ Beavis]

Make sure that you don't have the power leads swapped. The 5V light may be getting a very small amount of power via leakage from the DB37 through the PWM driver ICs.

Russ

[Kingofl337]

I would highly recommend you unplug everything for the Digital Sidecar. Then just provide 12v power and make sure the the three LED's turn on. Then connect the DB-37, then add a jumper, then start connecting the PWM cables. I think you might find a short in your wiring for the PWM cables.

[EricVanWyk]

I have a feeling that Russ is right with his "reversed power plus leakage" theory. Since adding the load of a servo kills the board entirely, you might have a very weak power path.

The BAT LED has an under-voltage detector. Since it is not on, it is indicating that it needs more voltage to properly run. Negative voltage also fails to turn on the LED.

I couldn't find your post on the usfirst.org site. Can you link?

[cabbagekid2]

I was so curious I had to drive down to the shop to figure out this problem right away. So....

Originally Posted by Russ Beavis

Make sure that you don't have the power leads swapped. The 5V light may be getting a very small amount of power via leakage from the DB37 through the PWM driver ICs.

Russ

I had no clue that power from the cRIO was able to feed the pwm cables. Turns out everything was wired to their correct place. But after pulling out the power from the power distribution board, looks like the Gnd connecting was clamping on to the insulation rather than the wire! ( we'll have to be more careful next time) So...no power to the digital sidecar!

After fixing the wire, all three lights go on. YAY!

Thanks Russ and Eric for helping us out!

[Russ Beavis]

I should have also mentioned about the insulation pinching. I've done that one myself. It's obviously important to make sure that you expose enough wire.

Glad to help!
Russ

[infiniteloop]

We opened up our sidecar and examined the circuit board; we found that the C6 capacitor was not soldered to both pads. Has anyone else opened up their sidecar and examined the circuit board?

[infiniteloop]

Oh, I should add that 2 of our 3 sidecars have this defect.

[Russ Beavis]

Breaking C6 is a known problem that shouldn't cause any problems.

Russ