RE: Tx Power on custom board

backstreet.devisor — Mon, 25 Mar 2024 18:05:08 GMT

Hi Bendik. Thanks for your response.

RE: Tx Power on custom board

Bendik Heiskel — Mon, 25 Mar 2024 08:37:18 GMT

Hi,

Apologies for the delay.

1. The RSSI you are printing is the RSSI measured at the device so it is the power of the received signal not the transmitted signal.
You will need to measure the RSSI at the other end of the connection. Since the receiving end is a phone you can use the nRF Connect application for measuring the received RSSI.

2. The RSSI can be influenced by external noise on the receving frequency, so other devices close by can influence it. Do you repeatedly see the same RSSI, or does it fluctuate?

3. txp is the requested TX power while txp_get is the actual TX power used. These can differ if the TX power requested isn't possible by the HW, for example if you request a TX power of 11dBm, while using the nRF21540 in fixed 10dB gain mode. The closes possible TX power in this situation is 10dBm, since the radio can't transmit at 1dBm.
The actual TX power used will not exceed the requested power, so the closest combination of SoC TX power and FEM gain will be used.

4. txp should take into account the FEM gain. As a sanity check you can read out the radio txpower register to see what the output power of the SoC is set to, aka the TX power without the FEM gain.

Best regards,

Bendik

RE: Tx Power on custom board

backstreet.devisor — Sun, 24 Mar 2024 21:29:45 GMT

Hi.

Any news?

RE: Tx Power on custom board

backstreet.devisor — Sun, 17 Mar 2024 20:51:09 GMT

Hi.

Are there any updates on this ticket?

Thanks.