Steering wheel issues

[jgannon]

I'm experimenting with a Thrustmaster Formula T2 steering wheel, and the feedback I'm getting in Dashboard (using the default code) is not what I would expect. When the wheel is centered, I get a value of 0 from p1_x. All the way to the left is 255. Turning to the right does nothing. p1_y stays stuck on 0 when I push the pedals. I'm getting the impression that perhaps the wheel has a non-standard pinout, but I'm not entirely sure. I know the wheel works just fine otherwise, because I've tested it with racing games on my computer. Has anybody else had this trouble programming a steering wheel to drive their robot?

[jgannon]

I did a little experimenting with a multimeter, and it looks as though the pinout is standard. It even behaves as a standard joystick in Windows (rather than using the custom driver). I still can't figure why I get no feedback from the pedals, and only in one direction on the wheel when I attach it to the OI.

[Al Skierkiewicz]

Joey,
I was not able to find the pinout for this device but what you describe sounds like the interface is using some of the other +5 volt pins in addition to just pin 1. The OI only feeds +5 on pin 1. I would suspect from your description that there is a second pot for right hand turns and that the pedals are also not getting +5 volts. You will need to check all pins with a multimeter. There are a number of places on the web to obtain gameport pinouts. Use one of those as a starting point. There is also the possibility that this is a MIDI device and as such is incompatible with the OI. Many modern audio cards have MIDI enabled game ports.

[jgannon]

Originally Posted by Al Skierkiewicz

Joey,
I was not able to find the pinout for this device but what you describe sounds like the interface is using some of the other +5 volt pins in addition to just pin 1. The OI only feeds +5 on pin 1. I would suspect from your description that there is a second pot for right hand turns and that the pedals are also not getting +5 volts. You will need to check all pins with a multimeter. There are a number of places on the web to obtain gameport pinouts. Use one of those as a starting point. There is also the possibility that this is a MIDI device and as such is incompatible with the OI. Many modern audio cards have MIDI enabled game ports.

Al,
I didn't realize that the OI didn't properly set up the other +5 and ground pins. In light of this, since pins 8, 9, and 15 are supposed to be +5, and pin 5 is supposed to be ground, I set Pwm1_green, Pwm1_red, and Pwm2_green high, and Pwm2_red low. This should accurately simulate the appropriate voltages in the wheel. I still only get feedback when turning the wheel to the left. However, I am now getting feedback from the gas pedal. When no pedals are depressed, I get 0. I can ease the gas pedal up over 200, and pressing the brake brings it back down to 0. Pressing the brake by itself does nothing. This seems to be a mirror of what's going on in the wheel. I will be making an adapter to connect pins 5, 8, 9, and 15 appropriately, but this should help me troubleshoot until then. Based on this new info, what's your hypothesis?

[Al Skierkiewicz]

Originally Posted by jgannon

Al,
I didn't realize that the OI didn't properly set up the other +5 and ground pins. In light of this, since pins 8, 9, and 15 are supposed to be +5, and pin 5 is supposed to be ground, I set Pwm1_green, Pwm1_red, and Pwm2_green high, and Pwm2_red low. This should accurately simulate the appropriate voltages in the wheel. I still only get feedback when turning the wheel to the left. However, I am now getting feedback from the gas pedal. When no pedals are depressed, I get 0. I can ease the gas pedal up over 200, and pressing the brake brings it back down to 0. Pressing the brake by itself does nothing. This seems to be a mirror of what's going on in the wheel. I will be making an adapter to connect pins 5, 8, 9, and 15 appropriately, but this should help me troubleshoot until then. Based on this new info, what's your hypothesis?

I need more input. I am guessing from your description of throttle-brake that they are mechanically interconnected. Pressing the brake when you have not run up the throttle would do nothing. I am more in favor of making an adapter box where the +5 from the OI gets wired over to the four supply pins and the other wires go straight through then to modify the OI porting. A small box, two 15 pin connectors and a little wire should do it. You might also add in a "Y" adapter so that you can get to two joystick inputs on the OI. I am also more inclined to open the wheel and see what's inside than most people so that would be where I would go next.

[jgannon]

Originally Posted by Al Skierkiewicz

I need more input. I am guessing from your description of throttle-brake that they are mechanically interconnected. Pressing the brake when you have not run up the throttle would do nothing. I am more in favor of making an adapter box where the +5 from the OI gets wired over to the four supply pins and the other wires go straight through then to modify the OI porting. A small box, two 15 pin connectors and a little wire should do it. You might also add in a "Y" adapter so that you can get to two joystick inputs on the OI. I am also more inclined to open the wheel and see what's inside than most people so that would be where I would go next.

There is only one potentiometer inside the wheel. The wiper is connected to +5 (pin 1), and one of the sides is connected to the x-axis (pin 3). Also connected to the wiper is a 12.5k resistor connected to a gray wire, but I haven't been able to determine where that leads to yet. When I test the pedals in Windows, pushing the gas by itself is like pushing a stick towards +y. Pushing the brake by itself is like pushing a stick towards -y. I can't really reach the actual contacts of the two potentiometers inside the pedals, but testing the connector indicates that they get their power from pin 15. I assume that's why they work now that I'm putting +5 to that pin. However, I do indeed plan to build an adapter like you described.