I may be missing something. I am trying to generate a square wave from a GPIO pin in a BLE application (SoftDevice 8.0). I tried libraries (nrf_pwm.c and nrf_pwm.h) in this post and also in this repo. I created two functions as follows:
#define V_CLK 5
static void pwm_init(void)
{
nrf_pwm_config_t pwm_config = PWM_DEFAULT_CONFIG;
pwm_config.mode = PWM_MODE_LED_255;
pwm_config.num_channels = 1;
pwm_config.gpio_num[0] = V_CLK;
// Initialize the PWM library
nrf_pwm_init(&pwm_config);
}
static void v_clock_start(void)
{
nrf_pwm_set_value(0, 127);
}
I have tested they worked without SoftDevice, as I could see a square wave between 0V and VCC in GPIO pin 5.
After that I went ahead with SoftDevice. I used "ble_app_beacon" from SDK 8.0.0 as the starting point, and removed BSP code since I was using a standalone nRF51822 module. I set USE_WITH_SOFTDEVICE to 1 in nrf_pwm.h. Also, I called pwm_init() before ble_stack_init() in main() function:
int main(void)
{
pwm_init();
ble_stack_init();
advertising_init();
advertising_start();
v_clock_start();
for (;; )
{
power_manage();
}
}
While BLE started successfully as I could see the iBeacon in my Master Control Panel Android app, I saw a flat 0V output from GPIO pin 5 in my oscilloscope. I tried to do the same thing to other working BLE apps of mine and they showed the same behavior. What was I missing?
