I believe I have a usb-chicklet problem. I am using the logitech 3d extreme, p/n 863225-1000. For some reason I am not getting correct pwm values outputting to the robot. When I pull back on the y-axis, I am getting different pwm values for pwms which should be the same. When I push forward on the y-axis everything is ok. This problem only occurs on the y and r axises. I have gone through the calibration mode twice with not difficulty. When I use a analog joystick without the usb-chicklet I have not problems. I just bought to logitech joystick 2 weeks ago. Any suggestions?

Are you trying to put it into any other mode than mode1? If so verify the functionality of it and if it is in mode1 then you blew the calibration procedure. There is a very critical step at the end of the calibration procedure where it has you hit a button to complete the cal. We missed this our first couple of times and it was staying in mode1.

Follow Jims suggestions and use dashboard to verify the data from the Chicklet.

how do you verify output with the dashboard (it may seem like a dumb question but I’m no programmer :D)

on the OI there is a small jumper next to the dashboard port. switch that to “OI” when you have done that connect the OI to a RC and power it up. then open IFI’s Dashboard viewer. the display should show all of the OI inputs. there is where you can see the outputted data from the chicklet.

hope that helps


Have you checked to make sure that the PWM’s are in the right spot? We had this problem this year. “If the program fails, its the mechanical side. If the mechanical side fails, check the program. If they both fail, find someone to blame”

You can also try to see if your speed controller is having problems. We had a similar problem and when we swapped out the speed controller it all worked fine.
good luck

we had the same problem. Turns out i accidentally was hitting the trigger while calibrating the axises… be carful and take things slooow… it works

also, check your power supply. when we used a battery, and it was low, the chicklet would spit out insane values.

When attacking a problem LIKE this, always use an analytical approach, will save you gray hair and high blood pressure.

#1 Check the values being reported by the joystick, using the dashboard (as per the procedure mentioned here). You should be able to SEE the values being reported by the joystick. If they are off, go back and try the calibration process again and repeat Step #1 before proceeding.

#2 Check the values at multiple steps INSIDE your code. Where are they read in? Where are they manipulated? Where are they written out? Ensure that you are operating on the right INPUT values and setting the right OUTPUT values. Are the outputs getting overwritten AFTER you write them? Search ALL the code for potential issues and examine your code flow.

#3 Use the dashboard again, but now in the RC mode to ensure that the values are being received and set at the RC output.

#4 Make sure you have the PWM cables plugged into the right things at BOTH ends of the cable.

#5 Check your electrical connections at the Vic/Spike. Loose connections make for erratic behavior.

I have done a LOT of programming and validation with just a OI & RC hooked up with some power. Seems the programmers never get to touch the real robot until the last minute :rolleyes: :rolleyes: :rolleyes: