Interrupt on both PWM edges

[machfax]

Hi Im using the pwm in the NRF52 with the following function: APP_ERROR_CHECK(nrf_drv_pwm_init(&m_pwm2, &config2, pwm2_handler));

in the Interrupt function "pwm2_handler" I receive an Interrupt after each full PWM cycle. Is there a possibility to receive an Interrupt as soon as the Ouput goes high (rising edge) and once again if the output goes down (falling edge)?

Thank you

[Jørgen Holmefjord]

Hi,

The available events from the PWM peripheral is described here. As you see, there are no event on rising or falling edge. However, you should be able to achieve this using GPIOTE. The GPIOTE peripheral can be configured to trigger interrupts on rising edge, falling edge, or both (toggle). Please checkout the GPIOTE example in the SDK.

Note that you most likely will have to use one extra pin for the GPIOTE, and physically connect this to the PWM signal. I don't think it is possible to configure GPIOTE to trigger interrupts on a pin configured as output.

Best regards,

Jørgen

[machfax]

Hi Jorgen

Thank you for the information. I think I need to use the DMA functuion like this:

NRF_PWM[x]->EVENTS_PWMPeriod -> NRF_TIMER[y]->TASKS_START NRF_TIMER[y]->EVENTS_COMPARE[0] -> NRF_SAADC->TASKS_START NRF_TIMER[y]->EVENTS_COMPARE[1] ->NRF_SAADC->TASKS_START

Did anybody know an example to configure the EasyDMA for this events above. Or can somebody tell me wehere is the discription to set the EasyDMA Mode correctly.

Thanks a lot

[Jørgen Holmefjord]

What do you mean by DMA? EasyDMA is used for peripherals to have direct access to data in memory. Did you mean PPI?

[machfax]

Yes PPI sorry. I think I need to use the PPI to do this. right?

[Jørgen Holmefjord]

Yes, PPI should work for this. Please have a look at the PPI example in the SDK for details on how to configre PPI.