Hello!
I am trying to use the LF RC oscillator on the NRF52840 in a BLE application, but I can’t connect to the device. I think that’s because the LF RC oscillator is never calibrated. I am testing on the BLE_GattServer example on the NRF52840-DK. I added the following configs to my mbed_app.json:
"config": {
"lf_clock_rc_calib_timer_interval": {
"value": 16,
"macro_name": "MBED_CONF_NORDIC_NRF_LF_CLOCK_CALIB_TIMER_INTERVAL"
},
"lf_clock_rc_calib_mode_config": {
"value": 2,
"macro_name": "MBED_CONF_NORDIC_NRF_LF_CLOCK_CALIB_MODE_CONFIG"
},
"lf_clock_xtal_accuracy": {
"value": "NRF_CLOCK_LF_XTAL_ACCURACY_500_PPM",
"macro_name": "MBED_CONF_NORDIC_LF_CLOCK_XTAL_ACCURACY"
}
},
"target_overrides": {
"*": {
...
"target.lf_clock_src": "NRF_LF_SRC_RC",
...
}
}
I have those from around the internet. I found though, that most of these macro end up in some
SoftDevice code that is not used. MBED_CONF_NORDIC_LF_CLOCK_XTAL_ACCURACY
isn’t even used at all (at least from what I found). How can I configure mbed to calibrate the LF RC oscillator regularly? Do I have to calibrate it “by hand” using the NRF SDK?