Hey!
I will post the whole code if necessary but for instance as I thought it would be a little glitch in my code, I tried to explain the basics of my problem for now:
- nrf52840 DK v1.1.0
- nrf5 SDK v17.02
- the template project in the peripheral folder is my starting point.
- Almost none of the peripherals has been disabled in the sdk_config.h
I have successfully configured and used SAADC, Timer, and TWI separately so I assume that my hardware is fine.
Also I have mixed the SAADC and a Timer with PPI , so on each compare event the conversion task is triggered.
Now I want to add a second task - in fork way- to the same PPI channel. but it looks like that the TWI handler is not called .
to do so , I have tried a few different configuration, because some of the docs was a bit vague to me somehow. so here is the current configuration:
- the function that is supposed to called everytime after the TWI handler is called, so the TWI instance would be ready for the next PPI trigger:
static void read_sensor_data_ppi()
{
m_xfer_done = false;
nrf_gpio_pin_toggle (LED4);
/* Read 1 byte from the specified address - skip 3 bits dedicated for fractional part of temperature. */
nrf_drv_twi_xfer_desc_t twi_desc_type ;
twi_desc_type.address = LM75B_ADDR;
twi_desc_type.primary_length = sizeof(m_sample);
twi_desc_type.p_primary_buf = &m_sample;
ret_code_t err_code = nrf_drv_twi_xfer(&m_twi, &twi_desc_type, NRF_DRV_TWI_FLAG_HOLD_XFER);
}
- This is the TWI handler code, I have add some extra lines for debugging, apparently you can ignore them, also the data_handler function is just a single log commend :
-
void twi_handler(nrf_drv_twi_evt_t const * p_event, void * p_context)
{
nrf_gpio_pin_toggle(LED2);
switch (p_event->type)
{
case NRF_DRV_TWI_EVT_DONE:
TWI_flag = 1;
if (p_event->xfer_desc.type == NRF_DRV_TWI_XFER_RX)
{
data_handler(m_sample);
nrf_gpio_pin_toggle (LED3);
read_sensor_data_ppi();
}
m_xfer_done = true;
break;
case NRF_DRV_TWI_EVT_ADDRESS_NACK:
TWI_flag = 0;
m_xfer_done = true;
//NRF_LOG_INFO("note");
break;
case NRF_DRV_TWI_EVT_DATA_NACK:
TWI_flag = 0;
m_xfer_done = true;
NRF_LOG_INFO("11note");
break;
default:
break;
}
}
-Here is the TWI initialization function which is almost just the same as it when I use it in blocking mode:
void twi_init(void)
{
ret_code_t err_code; // a variable to hold error code
// Create a struct with configurations and pass the values to these configurations.
const nrf_drv_twi_config_t twi_config = {
.scl = ARDUINO_SCL_PIN, // scl connected to pin 27, you can change it to any other pin
.sda = ARDUINO_SDA_PIN, // sda connected to pin 26, you can change it to any other pin
.frequency = NRF_DRV_TWI_FREQ_100K, // set the communication speed to 100K, we can select 250k or 400k as well
.interrupt_priority = APP_IRQ_PRIORITY_HIGH, // Interrupt priority is set to high, keep in mind to change it if you are using a soft-device
.clear_bus_init = false // automatic bus clearing
};
err_code = nrf_drv_twi_init(&m_twi, &twi_config, twi_handler, NULL); // initialize the twi
APP_ERROR_CHECK(err_code); // check if any error occured during initialization
nrf_drv_twi_enable(&m_twi); // enable the twi comm so that its ready to communicate with the sensor
//first time ready for read
read_sensor_data_ppi();
}
- the PPI configuration is here, I have just included the lines which are related to the TWI instance, as the PPI channel is working just fine with the SAADC task:
uint32_t twi_start_task_addr = nrf_drv_twi_start_task_get ( &m_twi,
NRF_DRV_TWI_XFER_RX );
err_code = nrf_drv_ppi_channel_assign(m_ppi_channel,
timer_compare_event_addr,
saadc_sample_task_addr);
err_code = nrf_drv_ppi_channel_fork_assign (m_ppi_channel,
twi_start_task_addr);
As you may notice , I have added a GPIO toggle command in the TWI handler, It just does not blink the way I have written the program, but why?
