Hi,
We are using nrf21540 in GPIO mode + mode pin ( and CONFIG_MPSL_FEM_NRF21540_RUNTIME_PA_GAIN_CONTROL) with an nrf52833.
We are developing under nrf connect sdk 3.0.2.
Using a multiple advertising set (extended advertising) composed by:
- One set of "legacy advertising"-
- One set of Long Range advertising (Coded PHY)
- Both have the the advertsing timings (i.e., interval min and max) set to same value: 100ms( BT_GAP_ADV_FAST_INT_MIN_2) and a150ms(BT_GAP_ADV_FAST_INT_MAX_2)
Using a power analyzer and relating nrf21540 PDN pin and MODE pin, i am observing a strange effect when the overall advertising TX power is set to 10 dBm:
- only the Long Range advertising respects the 10 dBm, the legacy advertising is always fixed to 20 dBm. Look at the screenshot below, the legacy adv. keeps mode gpio low (i.e., 20 dBm). Also the power consumption is higher during legacy advertising, hint of higher dBm TX.
- Using the extended advertising with only one advertising set, the issue is not present.
Our code has been devloped using as refrences:
- multiple adv set: https://github.com/nrfconnect/sdk-nrf/tree/v2.7.0/samples/bluetooth/multiple_adv_sets
- setting tx power: https://github.com/nrfconnect/sdk-zephyr/tree/v3.6.99-ncs2/samples/bluetooth/hci_pwr_ctrl
- Attached you can find the zephyr module we have developed and the KFragment for enbaling the ble-related stuff. The FEM Kconfig are set in our board defconfig file (
7485.ble.confCONFIG_MPSL_FEM_NRF21540_GPIO andCONFIG_MPSL_FEM_NRF21540_RUNTIME_PA_GAIN_CONTROL).