VTOL PWM channels from I2C, PCA9685

Alexander_Moore · May 29, 2018, 6:37pm

Looking to use the Pixracer on a VTOL aircraft with use of a PCA9685(1) I2c to PWM converter, for PWM expansion. Currently, I’m trying to rewrite the driver for the PCA9685 board so that it subscribes to the actuator_controls_virtual_fw instead of the Gimbal(2). Is there an easier way to change the driver so that the PCA9685 outputs a mirror of the AUX OUT ports? Let me know if I am on the right track with this, also let me know if I should post under another category.

(1) This is the PCA9685 Converter

(2) Line 313 is where I would need to start editing to subscribe to the correct channel.

github.com

PX4/Firmware/blob/master/src/drivers/pca9685/pca9685.cpp

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Romek_Ligocki · July 14, 2018, 10:24am

Hey Alexander,

I am also trying to rewrite PCA9685 driver. My goal is to control whole VTOL plane over I2C. In my code I already subscribed to control_group #0 and control_group #1. I think that these control groups must be mixed using mixer before I2C outputs them to PWM. Problem is that I was not able to understand how to mix outputs from control group.

If you are still working on this problem, maybe we can help each other.

Romek_Ligocki · July 14, 2018, 12:13pm

Is there topic to listen, that publish mixed outputs ready for PWM ? It would be easy to subscribe and send them over I2C.