Sidecar/Jaguar Communications Issue

[burde1jb]

Rookie Team #4327 Stuck in the mud and trying to get the robot rolling. We turn to you, wise veterans, for guidance.

We constructed everything to the "T" with the Quick Robot Build, the Getting Started with the 2012 FRC Control System, using Labview with the provided default simple robot code. So, basic everything.

Currently receiving the yellow flashing lights on the Jaguar motors which are connected to the CIMs.

The Driver Station verifies communication to the cRIO as well as robot code and therefore allows me to enable the robot. The DS also responds when I use a joystick as provided in the Kit of Parts. I can tell that buttons are being pressed.

The PWM cable is connected (though difficult to seat on the sidecar) in I/O slots #1 and #2. Jumpers were put in the corresponding places. I am receiving power to everything. The CIMs operate fine when directly connected to a battery. I have even tried swapping my two jaguars for two others.

Still the blinking yellow lights.

Any help would be greatly appreciated. We are at our wit's end looking for possible solutions.

[Joe Ross]

Did you rework the DB37 cable?

[rsisk]

Did you rework the DB37 cable?

DB37 Cable rebuild instructions (http://www.usfirst.org/sites/default/files/uploadedFiles/Robotics_Programs/FRC/Game_and_Season__Info/2012_Assets/DB37%20Ribbon%20Cable%20Assembly%20-%20Rework%20Instructions.pdf)

Follow the directions linked above, the only change, flip the female end of the ribbon cable, not the male end. The female end holds up better under the pressure of the vice (tip of the hat to Joe for this suggestion).

[Alan Anderson]

The PWM cable is connected (though difficult to seat on the sidecar) in I/O slots #1 and #2. Jumpers were put in the corresponding places.

Do you mean you put jumpers on the servo power pins next to the PWM outputs on the Digital Sidecar? While that won't hurt anything, you don't need them for controlling a Jaguar. They are only required when you are connecting a servo.

I am receiving power to everything. The CIMs operate fine when directly connected to a battery. I have even tried swapping my two jaguars for two others.

Still the blinking yellow lights.

Describe for us what your Robot Signal Light (either the big amber one or the little green one next to the RSL pins on the Digital Sidecar) is doing.

[Kevin Selavko]

They are supposed to blink yellowish orange when they are not sending power, red when in reverse, and green when going forward.

[Tom Line]

They are supposed to blink yellowish orange when they are not sending power, red when in reverse, and green when going forward.

That is not precisely true. When the robot is disabled and they are receiving no signal, they will blink. When they are receiving a signal, they are solid. When full forward is commanded, green, and full reverse, red. To put it another way, when the robot is enabled, the jags do NOT blink.

A blinking jag means no command signal - i.e. a poor pwm cable, a bad pwm connection, a malfunctioning digital sidecar, a bad ribbon cable, or bad code.

[Kevin Selavko]

Ohh ok, well today we were having problems because someone over tightened a zip tie and it cut a pwm cable, so check all of them.

[burde1jb]

Could not be more grateful. :D It was indeed the DB37 cable being backwards. Another local team let me borrow their DB37 cable from last (not the ribbon) and everything worked great.

I reversed the ribbon, but when tightening with the vice, I went too far and bent the metal. :ahh: When testing, the CIMs began turning with no input in a spastic fashion (jolt forward, jolt back, sporadic behavior).

So I ordered the exact cable model from last year's competition as well as replacements for the male end connector for the ribbon I wrecked.

This ribbon reversal was also a problem with two local teams. Do they pull this stuff on purpose? If so, can we make a rule that it not go against Rookie teams? :mad: