REXYGEN Community Forum

ier123

Member

Registered: 2016-03-16

Posts: 5

PWM pin mode

I am trying to use the PWM pin mode to control a basic motor. As documented in the Raspberry Pi Rex User Guide, it says that GoTo RPI__PWM18 will produce output on pin 18. I am getting no output from pin 18 when I implement this block. However, if I rename the block to RPI__GPIO18, I get output on pin 18. A picture of the block I've set up is attached. Any suggestions on setting up PWM would be helpful. Thanks in advance.

tomáš čechura

Administrator

Registered: 2016-02-22

Posts: 371

Re: PWM pin mode

Please, can you attach whole Rex project (.mdl files)? It would be much easier to find the issue in your implementation.

Regards, Tomas

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Raspberry Pi as a miniature industrial PC. Analog and digital I/O, RS-485 and 1-Wire bus.

ier123

Member

Registered: 2016-03-16

Posts: 5

Re: PWM pin mode

Attached are two .mdl files: motor_task.mdl and motorTest.mdl
On the Pi (without REX) we use the RPIO library and the PWM commands to control the output and change the frequency and/or duty cycle, but have run into some issues trying to copy this type of functionality via REX.  Is there a demo file for a working PWM setup with a Raspberry Pi?  Do you have any guides for the proper setup for a Pi?

josar

Member

From: Czech Rep.

Registered: 2015-11-03

Posts: 17

Re: PWM pin mode

The PWM range is 0..1023. Multiply your boolean signal by 1023 to get full duty cycle (use GAIN block).