nrf21540

RE: nrf21540

JONATHAN LL — Tue, 13 Apr 2021 14:32:20 GMT

Hi,

[quote user="Nahan_Trogn"]When I set mode = 1 in CONFREG0, after that, the value I read from that register is 0x23! This won't happen when I set mode to 0.[/quote]

Changing the MODE triggers a reload of the default value. depending on the action sett/clear different default or end user values will be loaded.

"To configure the output power through pins, MODE can be used to set TX power control to one of two preset values. Preset values are used to update the TX_Gain value when MODE control changes in the Program state. The same functionality can be achieved by writing to the MODE bit in CONFREG0. Custom preset values can be stored in UICR and selected as default."

"Changing MODE or the MODE bit in CONFREG0 will always trigger a reload of a default value to TX_Gain. Setting any of these will load POUTB. Clearing any of these will load POUTA. The default value will also be used even if a new value is loaded to TX_Gain during the SPI write cycle changing the MODE bit."

[quote user="Nahan_Trogn"]I know that preset values can be stored in UICR, but what does the field TX_Gain in CONFREG0 mean[/quote]

TX Gain is configured by writing the gain value over SPI to register CONFREG0 TX_Gain field.

[quote user="Nahan_Trogn"]What is the special purpose for this design?[/quote]

Dual antenna port with antenna diversity support, so it gives you the option to use two antennas.

Regards,
Jonathan

RE: nrf21540

Nahan_Trogn — Mon, 29 Mar 2021 15:31:46 GMT

Hi,

1) I know that preset values can be stored in UICR, but what does the field TX_Gain in CONFREG0 mean? Can I set custom Tx_Power in CONFREG0 instead of UICR?
2) When I set mode = 1 in CONFREG0, after that, the value I read from that register is 0x23! This won't happen when I set mode to 0.

3) We can use both Tx and Rx in the same antenna, but the design has two antennas. What is the special purpose for this design?

Thanks.

RE: nrf21540

JONATHAN LL — Mon, 29 Mar 2021 15:18:57 GMT

Hi,

Section 5.4 in the PS:

"Preset values are used to update the TX_Gain value when MODE control changes in the Program state. The same functionality can be achieved by writing to the MODE bit in CONFREG0. Custom preset values can be stored in UICR and selected as default."

Table 7 illustrate how to use user defined.

Regards,
Jonathan