Toggle GPIO on BLE transmit

[cblack-f3]

I am curious if the nRF52840 has the ability to assert a gpio when the BLE transmission is active?

[hmolesworth]

Try this; let me know if it works as I haven't tested it yet. Choose any one of the events, or multiple events if you have spare io pins and spare PPI channels. Edit: I changed to use Set/Clear, was originally using toggle

#define PIN_RADIO_TEST        26 // Any spare pin eg P0.26
#define RADIO_GPIOTE_CH        0
#define BLAH_BLAH_PPI_CH_SET   0
#define BLAH_BLAH_PPI_CH_CLEAR 1

   // Up to three tasks can be used in each GPIOTE channel for performing write operations to a pin, two
   // are fixed (SET and CLR), and one (OUT) configurable to perform Set, Clear or Toggle
   //  - "HiToLo" Task mode: Clear pin from OUT[n] task
   NRF_GPIOTE->CONFIG[RADIO_GPIOTE_CH] = GPIOTE_CONFIG_MODE_Task       << GPIOTE_CONFIG_MODE_Pos | 
                                         GPIOTE_CONFIG_POLARITY_HiToLo << GPIOTE_CONFIG_POLARITY_Pos | 
                                         PIN_RADIO_TEST                << GPIOTE_CONFIG_PSEL_Pos | 
                                         GPIOTE_CONFIG_OUTINIT_Low     << GPIOTE_CONFIG_OUTINIT_Pos;
 // NRF_PPI->CH[BLAH_BLAH_PPI_CH      ].EEP = (uint32_t)&NRF_RADIO->EVENTS_READY;       // RADIO has ramped up and is ready to be started
    NRF_PPI->CH[BLAH_BLAH_PPI_CH_SET  ].EEP = (uint32_t)&NRF_RADIO->EVENTS_ADDRESS;     // Address sent or received
 // NRF_PPI->CH[BLAH_BLAH_PPI_CH      ].EEP = (uint32_t)&NRF_RADIO->EVENTS_PAYLOAD;     // Packet payload sent or received
    NRF_PPI->CH[BLAH_BLAH_PPI_CH_CLEAR].EEP = (uint32_t)&NRF_RADIO->EVENTS_END;         // Packet sent or received
 // NRF_PPI->CH[BLAH_BLAH_PPI_CH      ].EEP = (uint32_t)&NRF_RADIO->EVENTS_DISABLED;    // RADIO has been disabled
 // NRF_PPI->CH[BLAH_BLAH_PPI_CH      ].EEP = (uint32_t)&NRF_RADIO->EVENTS_DEVMATCH;    // A device address match occurred on the last received packet
 // NRF_PPI->CH[BLAH_BLAH_PPI_CH      ].EEP = (uint32_t)&NRF_RADIO->EVENTS_DEVMISS;     // No device address match occurred on the last received packet
 // NRF_PPI->CH[BLAH_BLAH_PPI_CH      ].EEP = (uint32_t)&NRF_RADIO->EVENTS_RSSIEND;     // Sampling of receive signal strength complete.
 // NRF_PPI->CH[BLAH_BLAH_PPI_CH      ].EEP = (uint32_t)&NRF_RADIO->EVENTS_BCMATCH;     // Bit counter reached bit count value.
 // NRF_PPI->CH[BLAH_BLAH_PPI_CH      ].EEP = (uint32_t)&NRF_RADIO->EVENTS_CRCOK;       // Packet received with CRC ok
 // NRF_PPI->CH[BLAH_BLAH_PPI_CH      .EEP = (uint32_t)&NRF_RADIO->EVENTS_CRCERROR;    // Packet received with CRC error
 // NRF_PPI->CH[BLAH_BLAH_PPI_CH      ].TEP = (uint32_t)&NRF_GPIOTE->TASKS_OUT[MOTOR_GPIOTE_CH];
    NRF_PPI->CHENSET               = ((1UL << BLAH_BLAH_PPI_CH_SET) | (1UL << BLAH_BLAH_PPI_CH_CLEAR));