We have just got our hands on some Tetrix. Overall the Tetrix implementations works well (Lejos 0.9.1), though we have a problem with 'setPower(power) when using a DC-motor WITHOUT shaft encoders. The setPower more acts like some kind of acceleration and doesn't change the power at all.
We have read on another webpage http://www.robotc.net/forums/viewtopic.php?f=33&t=1020 that the TetrixMotorController box have a build in PID-controller which might be turn on as default. From robots.net forum:
Do you have the shaft encoders installed? If not, turn off PID control. What is probably happening is:
- You are asking for a particular speed
- The controller applies power to the motor
- There is no data coming from the shaft encoder which it interprets as the motor being stopped
- The controller applies more power to the motor to try to get it moving
- Round and round until (more or less) full power is being applied.
We havn't found any way to turn off the PID-regulation. Does any of you know how this could be possible or if the problem is something completely different?