Hello,
I have an application in which I need to get RSSI before, during and after any BLE connection has been made. The RSSI measurements are being used to quantify the co-channel interference generated by a WIFI radio. I need to make this measurement independent of BLE connection state. For example, I am not interested in the RSSI while the last packet was received.
In my application, I need to measure RSSI, then control a 3rd-party "custom" RF frontend based on the measurement, then repeat. It is important that I can make these measurements asynchronously and independently of a BLE connection.
The problem I am seeing is when I call the get_rssi() function below. The system hangs or prints "<error> app: Fatal error" to the serial console.
uint8_t get_rssi(void)
{
NRF_RADIO->EVENTS_RSSIEND = 0;
NRF_RADIO->TASKS_RSSISTART = 1;
while (NRF_RADIO->EVENTS_RSSIEND == 0);
uint8_t rssi = NRF_RADIO->RSSISAMPLE;
return rssi;
}
It would seem that the Line "NRF_RADIO->TASKS_RSSISTART = 1;" is the problem. If I omit this line, then RSSI measurements are stale (do not updated frequently enough).
Till now, my work has been on top of the "ble_app_att_mtu_throughput" example using S140 SoftDevice. I am using the "nRF5 v16.0.0" SDK.
My hardware is the pca10056 nRF52840 evaluation board and a custom platform. I see the same issue on both platforms.
My Questions are:
(1) Can I use the RSSI registers directly while using a SoftDevice?
(2) Is there an API method to get instantaneous RSSI?
Thanks
