Post by Frisbone on Sept 24, 2013 19:31:35 GMT -5
Well I think using PWMs may be an issue. I have observed the horizontal movement affect vertical movement and vice versa. It seems to peak at about mid-way through either direction for either axis (-.5 or +.5 percentage, or .4V and 1.2V).
No idea where in the chain it is coming from but given that we have an oscillating signal coming off the PWM and both wires follow eachother closely there is a good bet that the lack of shielding is inducing current in the other wire and the signal is present but at a much lower amplitude. Not sure I understand why it would peak at those two voltages unless the associated frequencies are harmonics of some kind.
So this is a warning for he who is building anew. Do as much as you can do decouple the X and Y signals if you use PWM. Or, don't use PWM (as I suspect is your plan).
Trying to think of a way to prove that it is the hardware. THink I'll have to take apart the gun to do it and I don't really want to do that right now. I think I'll forget it for the time being. This voltage induction though is a possible partial explanation or why my square movement isn't exactly square. That coupled with the fact that I plotted the square from a single perspective and when that perspective shifts with the camera-view changes - it wouldn't observe the travel as directly up and down anyway.
No idea where in the chain it is coming from but given that we have an oscillating signal coming off the PWM and both wires follow eachother closely there is a good bet that the lack of shielding is inducing current in the other wire and the signal is present but at a much lower amplitude. Not sure I understand why it would peak at those two voltages unless the associated frequencies are harmonics of some kind.
So this is a warning for he who is building anew. Do as much as you can do decouple the X and Y signals if you use PWM. Or, don't use PWM (as I suspect is your plan).
Trying to think of a way to prove that it is the hardware. THink I'll have to take apart the gun to do it and I don't really want to do that right now. I think I'll forget it for the time being. This voltage induction though is a possible partial explanation or why my square movement isn't exactly square. That coupled with the fact that I plotted the square from a single perspective and when that perspective shifts with the camera-view changes - it wouldn't observe the travel as directly up and down anyway.