Issues with PWM and S210

RE: Issues with PWM and S210

Ole Bauck — Thu, 16 Jun 2016 11:23:41 GMT

Which SDK are you using? You should find out why it returns NRF_ERROR_INVALID_STATE, not change the return value to NRF_SUCCESS, then you will get undefined behaviour. The state is set in the init, uninit, enable and disable functions. The state is set to NRF_DRV_STATE_POWERED_ON in the enable function. You are probably calling init, uninit or disable after you called the enable functions.

RE: Issues with PWM and S210

Jay — Wed, 08 Jun 2016 16:43:48 GMT

The issue is coming from here in app_pwm.c

if (p_cb->state != NRF_DRV_STATE_POWERED_ON)
{
    return NRF_ERROR_INVALID_STATE;
}

where it returns the NRF_ERROR_INVALID_STATE after few seconds of running the above code. I changed NRF_ERROR_INVALID_STATE to NRF_SUCCESS and after, instead of getting stuck at 16% PWM and restarting after few seconds, the PWM continues at 16% and never restarts. So, as your link suggests, it seems like an error condition is returned from the PWM duty cycle set function and system restarts. However, I commented out the following in the app_error.c but the nRF51422 still restarts:

...
NVIC_SystemReset();
...
m_error_code = error_code;
m_line_num = line_num;
m_p_file_name = p_file_name;
UNUSED_VARIABLE(m_error_code);
UNUSED_VARIABLE(m_line_num);
UNUSED_VARIABLE(m_p_file_name);
__disable_irq();
while(loop);

RE: Issues with PWM and S210

Ole Bauck — Tue, 07 Jun 2016 11:50:51 GMT

Which SDK are you using? Can you find out why the code resets? Probably it is because you are running into an error condition, see here.