Softblink in NCS/Zephyr

[john23094]

Hi,

I'm asking about the softblink library that was in the NRF5 SDK. Is there anything equivalent that nordic has provided for the new NCS/Zephyr SDK? 

What I liked about it is that it could fade an LED up/down with minimal CPU intervention (I think it used PPI maybe). But there isn't an equivalent in NCS/Zephyr SDK, you'd have to manually do it in code. 

[Vidar Berg]

Hi,

There isn't a soft blink implementation in Zephyr that does not require CPU involvement as far as I can tell. Is power consumption a concern in your application? If not, I think the easiest solution will be to implement it with PWM using the nRFX api directly.

Best regards,

Vidar 

[john23094]

Hi Vidar,

Power is a concern but CPU availablility is the highest concern at the moment.

I actually read the source code for softblink lib. and saw that actually it was just using a timer and ISR to step and increase  the duty cycle which is actually a lot more inefficient than I thought it was. 

Yes I actually went on to read the PWM module doc. directly and I can do what I want by configuring it, so I will use it directly.

[Vidar Berg]

Hi,

I've quickly put together an example using the NRFX PWM driver in case it helps, please see attached. 

4848.hello_world_pwm_softblink.zip

Much of the code was copied from the pwm peripheral example in the nRF5 SDK.

[john23094]

Hi Vidar,

That code was really useful thanks very much for that. It's behaving now exactly how I I wanted it!