I combined the BLE UART and SPIS Peripheral example of SDK V17.0.2 to receive data from a microcontroller using SPIS protocol in every 32 milliseconds and send it over through BLE at 128 milliseconds intervals. However, the EasyDMA is turned on all the time (see the main loop in the attached code) and thus the nRF52832 is consuming around 2mA current all the time.
So, to reduce current consumption, I want to enable EasyDMA only when the SPIS transfer is occurring i.e., 32 milliseconds. Thus, I am planning to use PPI and GPIOTE to sense chip select (CS) pin and use it as an Event and enable EasyDMA as the Task.
However, as I went through the documentation, I could not find any reference on how to get the task endpoint address for EasyDMA. I need that address to configure the PPI.
Please let me know how can I get the EasyDMA task endpoint address or any other way to enable EasyDMA only for 32 milliseconds.
int main(void)
{
bool erase_bonds;
// Initialize.
log_init();
timers_init();
power_management_init();
ble_stack_init();
gap_params_init();
gatt_init();
services_init();
advertising_init();
conn_params_init();
// Start execution.
NRF_LOG_INFO("Debug logging for UART over RTT started.");
advertising_start();
conn_evt_len_ext_set(true);
uint32_t err_code;
//SPI Initialization
NRF_LOG_INFO("SPIS example");
nrf_drv_spis_config_t spis_config = NRF_DRV_SPIS_DEFAULT_CONFIG;
spis_config.csn_pin = APP_SPIS_CS_PIN;
spis_config.miso_pin = APP_SPIS_MISO_PIN;
spis_config.mosi_pin = APP_SPIS_MOSI_PIN;
spis_config.sck_pin = APP_SPIS_SCK_PIN;
APP_ERROR_CHECK(nrf_drv_spis_init(&spis, &spis_config, spis_event_handler));
// Enter main loop.
for (;;)
{
// Reset rx buffer and transfer done flag
if (master_connected == true) //Start SPIS receive only when master is connected
{
memset(m_rx_buf, 0, m_length);
spis_xfer_done = false;
APP_ERROR_CHECK(nrf_drv_spis_buffers_set(&spis, connected_buf, m_length_connected, m_rx_buf, m_length));
connected_buf[m_length] = 1; //connected_buf is used to send data to the SPI master
while (!spis_xfer_done)
{
__WFE();
}
//__NOP();
}
else
{
connected_buf[m_length] = 0; //connected_buf is used to send data to the SPI master
}
//NRF_LOG_INFO("idle state started.");
idle_state_handle();
}
}
