Teensy 2.0 project

[Stuggy]

I just received my Teensy 2.0 pins to try a joystick project . This is an existing project that adds USB support to an old joystick.

I created my breadboard and wiring etc. It works. However, it doesn't work fully. There are 2 issues:

(1) When I connect is to my XP laptop I get "this device has exceeded the power supply of the usb port" or similar. I don't get this message on my Windows 7 machine
(2) When I press the buttons on the stick some work and some don't. Also the sliders/axis are erratic.

I realize that this may not be a Teensy issue but since others have built working versions I thought it was worth a question here.

The exceeding the power supply message is a weird one given that it is just a joystick.

 

[PaulStoffregen]

Did you connect more hardware to the Teensy, which is being powered by the USB port?

Adding too much capacitance across the power supply pins can cause trouble. The USB spec says 10 uF maximum, and Teensy already has three 2.2 uF capacitors. I've seen some Macs able to detect too much current charging 47 uF capacitance. Most PCs have inferior quality USB overcurrent detection (that won't protect you even at extremely high currents), but perhaps your XP laptop has good or even overly sensitive circuitry?

It's also possible to get a purely software-based warning, based on the data in the USB descriptor that tells the operating system how much current Teensy will use. Teensy defaults to claiming 100 mA current, which the USB spec says all USB ports are supposed to be able to provide. Usually you would not get this sort of issue unless you've hacked the USB descriptors and increased the current spec.

 

[Stuggy]

I connected the joystick. The project is here: http://www.descentbb.net/viewtopic.php?f=8&t=15526&start=180&hilit=sidewinder+3d+pro+usb

I am a decent C++ coder but for this project I just went with instructions and built the breadboard and installed the .hex file (no code of my own). The stick was recognized by Windows 7 (not XP because of the power exceeded message). I should try without the stick plugged in.

At this point I am not sure what the problem is.

Any thoughts on the somewhat faulty readouts since others have successfully built the board and have it working? I mainly want to use it on my Windows 7 machine so I am not really worried about the error on XP laptop I just thought it might highlight the problem.