Hello Nordic support,
I am using two nRF54L15 devices with NCS v3.0.1 and ESB DPL at 1 Mbps. Auto ACK is enabled, the payload is 252 bytes, and the retransmit count is 9.
The PTX power remains fixed. I only change the PRX TX power, which controls the ACK transmission power:
esb_stop_rx(); esb_set_tx_power(txp); esb_start_rx();
I get the following unexpected results:
PRX TXP 8 dBm: about 700 kbps PRX TXP 7 dBm: about 160 kbps PRX TXP 6 to 4 dBm: about 75 kbps PRX TXP 3 dBm: about 90 kbps PRX TXP 2 dBm: about 430 kbps PRX TXP 1 to 0 dBm: about 700 to 760 kbps
The PRX RSSI remains around -54 dBm because the PTX power does not change.
At 6 to 4 dBm, the packet rate drops from about 350 packets/s to 38 packets/s. It looks like the PTX is exhausting all retransmission attempts because it does not receive the ACK correctly.
Why does the ACK link fail mainly when the PRX TX power is between 3 and 7 dBm, but work normally again at 0 to 2 dBm?
Is this the correct way to change the PRX ACK power dynamically? Are there any known ESB or RADIO issues in NCS related to these TX power levels? (I have also tried 3.3.0)
Thank you.