A simple PWM LED approach for the Thingy:91

Question

I'm trying to drive the RGB LED light on the Thingy:91. So far, I've not been successful. I was hoping that by listing the steps I perform I might be able to get some advice. This is the first time that I've dealt with PWM. Here are the steps I'm presently taking: 
 1. Using PWM0_NS (my program is insecure), assign pins p0_29, p0_30, and p0_31 having set them up as push/pull output with an initial level of high. 2. Set the period of the PWM to 500hz. 3. I then loop around wanting to toggle the LED on and off by setting the duty of all three channels to the max duty (on) and 0 (off) with about 1 second sleep in between. 
 Does this approach seem reasonable? I really want the simplest PWM RGB LED demo I can; think of blinky for the RGB LED. 
 Thanks for any help.

Albrecht Markus Schellenberger · Accepted Answer

Hello Christopher, 
 Zephyr provides a straightforward sample showing how to control an LED with a PWM peripheral. 
 You can find it in your ncs folder: ../zephyr/samples/basic/blinky_pwm. 
 It doesn’t work for the Thingy:91 from scratch, but you can easily get it to work with the following modifications: 
 
 Create an overlay file in your application root called: thingy91_nrf9160ns.overlay 
 Add the following lines to the overlay file 
 
 / {
 pwmleds {
 compatible = "pwm-leds";
 pwm_led0: pwm_led_0 {
 pwms = < &pwm0 0x1f >;
 };
 };

 aliases {
 pwm-led0 = &pwm_led0;
 };
}; 
 
 Build and run 
 
 The application should now trigger the blue LED colour of the lightwell LED. 
 I hope this is a good starting point for you! 
 Regards, 
 Markus

A simple PWM LED approach for the Thingy:91

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