Phidgets Forums

Hello,
I've been playing with the servo phidget and the stepper phidget in the past but this is my first time using a DCC module.

It's not clear to me how I can make my motor positioning synchronous.
In the past I was monitorting the positionChanged event and blocking until the current position is the target position, but with a DC motor and depending on the PID, the motor might overshoot.

So here are my questions:
- Do you confirm that voidPhidgetMotorPositionController_setTargetPosition() is asynchronous?
- Do you confirm that the callback of voidPhidgetMotorPositionController_setTargetPosition_async() is not called when the position is reached, but when the targetPosition has been sent to the microcontroller?
- How do you recommend to program the detection of "position reached"?

Thanks in advance.

setTargetPosition() is synchronous in that it returns once the command has been accepted by the board. setTargetPosition_async() is basically the same, but returns immediately. It can take 10s of milliseconds to send a command to the board and hear back - the async call is there for sending commands to multiple channels in parallel.

You'll need to monitor the PositionChange or DutyCycleUpdate events to determine when it's reached position.

-Patrick

Thanks a lot, works great this way.
I have one last question: is it possible to use an input from the VINT Hub and use it as a homing switch for the encoder?
This can of course be done from the PC, but I was wondering if it can be done at the micro-controller level.
Thanks in advance.