[Bug]: setting txpwr to 18 crahses lora chip

[dl9sau]

Category

Hardware Compatibility

Hardware

T-Beam

Firmware Version

2.5.15.79da236

Description

Hardware: T-Beam v1.2. Firmware 2.5.15.79da236 (and also the previous one):
Ich changed (via linux app, V1.x) my txpower to 18 dBm. And wondered 8 days that I did not receive any packet.
When I trx to TX, nothing is sent (verified via SDR-RX).
Old value was 24 dBm (which is out of the spec of the t-beam - that's why I corrected it and decided 18 dBm).
The app (via bluetooth) needed some time > 1min to read settings from the device.
I upgraded firmware to 2.5.15.79da236. Still no RX/TX. I did a config reset and uploaded the saved config. No change.

I did rememeber my config change from 8 days ago and set 20 dBm again. -> RX/TX works fine again.

Today I dig a bit deeper in the problem:
I changed to 18 dBm again -> No RX/TX and app took much time to read/write config afterwards.
I changed to 16 dBm -> RX/TX worked fine and app worked as expected.
I changed to 18 dBm -> No RX/TX and app took much time to read/write config afterwards.
I changed to 20 dBm -> RX/TX worked fine and app worked as expected.

From my lora-arps amateur radio firmware project I know that 18 dBm is a valid setting; while programming, I noted
"{Power, max_tx_power} = {{8, 2}, {20, 5}, {28, 7}, {34, 8}, {44, 11}, {52, 13}, {56, 14}, {60, 15}, {66, 16}, {72, 18}, {80,20}}"

I did not search for the power settings code in the meshtastic sources.

Greetings,

• Thomas dl9sau

Relevant log output

No response