PWM current / power consumption

RE: PWM current / power consumption

Ole Bauck — Fri, 15 Jul 2016 12:21:54 GMT

How high and how short? You can only start the PWM and comment out all other code to only measure PWM.

RE: PWM current / power consumption

hawk — Fri, 15 Jul 2016 08:07:12 GMT

hi, ole: it is very strange. i test the pwm by test equipment to check the voltage, it is good. but tester guy use current test equipment to check the pwm, but the current sometime is high very short time. there are some burrs... How to deal with this problem.. so i want to disable all the other interrupts while PWM is running to check other interrupts influence this pwm.

RE: PWM current / power consumption

Ole Bauck — Wed, 13 Jul 2016 11:13:38 GMT

You can comment out ble_advertising_start(..);, then the device will not start advertising and the current should be more or less stable.

RE: PWM current / power consumption

hawk — Tue, 12 Jul 2016 04:17:37 GMT

i make pwm by setting gpio high or low， and test the current and found the current sometime is not still。 can i disable ble ？

RE: PWM current / power consumption

Ole Bauck — Wed, 16 Dec 2015 08:59:38 GMT

What other things are you running? Could you try to only run the PWM part and see if the current is still the same? Are you running multiple instances of PWM?

The PWM driver will require the high frequency clock to run, which will cause an increase in current consumption. The high frequency clock will only be stopped if no resources are requiring it. If you have to PWM instances enabled, then disabling one of them will not decrease the current consumption since the high frequency clock is still running.

RE: PWM current / power consumption

FormerMember — Wed, 16 Dec 2015 05:01:22 GMT

I did it as you mentioned that including app_pwm.c and app_pwm.h files from sdk 10. Therefore I only use app_pwm_disable(), but the current still in instability 0.4mAh to 0.8mAh.

It can't be fixed for now?

RE: PWM current / power consumption

Ole Bauck — Fri, 11 Dec 2015 10:13:47 GMT

The SDK 9 driver has some known issues regarding app_pwm_uninit() and app_pwm_disable(). I will therefore suggest that you use the SDK 10 driver. You only need to call app_pwm_disable(), as this will stop the timer and reduce the current consumption. app_pwm_uninit() is for deallocate the resources used by the pwm and are therefore not necessary to call in your case. You should also remove the nrf_drv_gpiote calls, this is fixed by the driver. Doing nrf_drv_gpiote calls on the pwm pin may create issues with the pwm driver.

If you don't want to migrate the project to SDK 10, it should be possible to only include the app_pwm.c and app_pwm.h files.