Feature Request V4 4.3 LNA switching - with test results

[towerviewcams]

I have just finished the first ever tests of the new version 4.3 Heltec V4 board with LNA being switched into bypass. This is huge step forward! When the below command is used, it also disables the amplifier so TX output is +22

Total 4.3 board power draw with current dev merge of recent PR#1867 by @Quency-D and the older powersaving that is in this code from @IoTThinks.

I changed the code per @Quency-D direction of setting "bool lna_enabled=true;" set to "false"

"bool lna_enabled=false;" = (LNA-BYPASS & power off) - total board current draw 5.8mA in powersave sleep

"bool lna_enabled=true;" = (LNA-on & power on) - total board current draw 12.8mA in powersave sleep

***Requesting CLI command to remotely control this LNA. This will allow for so many options both in power draw, noise level and more.

@weebl2000 @liamcottle @Socalix @recrof @jbrazio @AI7NC

[IoTThinks]

@towerviewcams Impressive for Heltec v4.3 with bypass LNA at 5.8 mA.

It is 50% lower than NRF52 with stock MC 1.14 at 8-9mA and matched NRF52 with PS 14 at 5.8mA.

I will add Heltec v4.3 to PS14.1 in a few days.

FYI, a lot of MT users convert to MC due to powersaving.
Their Heltec boards cannot live with solar and MT.

Thanks for testing.
Please help to see how well Heltec v4 with bypass LNA performs in noisy RF site.

[towerviewcams]

I will add Heltec v4.3 to PS14.1 in a few days.

FYI, a lot of MT users convert to MC due to powersaving. Their Heltec boards cannot live with solar and MT.

Thanks for testing. Please help to see how well Heltec v4 with bypass LNA performs in noisy RF site.

@IoTThinks as soon as I get PS14.1 I will test on BOTH a 4.3 and 4.2 board in my lab. Then, deploy to easy repeater site with over 500MW of broadcast noise. I will be home from traveling for work on Tuesday night. Maybe can start testing Wednesday if your ready.

[Quency-D]

That's great. Also, the CLI is already in process.

[towerviewcams]

That's great. Also, the CLI is already in process.

@Quency-D will the power amplifier be able to stay on so we still get +27 and have the LNA in bypass?

[Quency-D]

That's great. Also, the CLI is already in process.

@Quency-D will the power amplifier be able to stay on so we still get +27 and have the LNA in bypass?

Yes, that's how it was designed.

[Quency-D]

That's great. Also, the CLI is already in process.

@Quency-D will the power amplifier be able to stay on so we still get +27 and have the LNA in bypass?

This is the command we are currently testing; you can try it if you're interested. Simply download the firmware from https://github.com/Quency-D/MeshCore/tree/cli-lna-command, and then run this Python script from https://github.com/Quency-D/meshcore-cli/tree/lora-lna-cli.

[towerviewcams]

This is the command we are currently testing; you can try it if you're interested. Simply download the firmware from https://github.com/Quency-D/MeshCore/tree/cli-lna-command, and then run this Python script from https://github.com/Quency-D/meshcore-cli/tree/lora-lna-cli.

I'm not understanding your direction. I tried to take the code and build an image with Platformio but that didnt work. I dont understand the script with the firmware. Maybe you could give a little more detail how do build this .bin file so I can flash and test

[Quency-D]

I'm not understanding your direction. I tried to take the code and build an image with Platformio but that didnt work. I dont understand the script with the firmware. Maybe you could give a little more detail how do build this .bin file so I can flash and test

Hi, @towerviewcams . This is the pre-compiled firmware: https://github.com/Quency-D/MeshCore/actions/runs/23476338553/artifacts/6074662036. You can download it directly and flash it.

Use Python to run the scripts in https://github.com/Quency-D/meshcore-cli/tree/lora-lna-cli. The commands are the same as if you had installed meshcore-cli directly.

python.exe meshcore_cli.py -s COM491 chat

This is a demonstration of remote control.

A416A94E|*> /9791b78edd4a/get radio.fem.rxgain
Heltec Repeater (D): > on
A416A94E|*> /9791b78edd4a/set radio.fem.rxgain on
Heltec Repeater (D): OK - LoRa FEM RX gain on
A416A94E|*> /9791b78edd4a/set radio.fem.rxgain off
Heltec Repeater (D): OK - LoRa FEM RX gain off

[Quency-D]

The submitted code can be viewed at #2140.

[IoTThinks]

@towerviewcams You may try to use the CLI commands in your repeaters with the custom firmware.

set radio.fem.rxgain on

set radio.fem.rxgain off

[towerviewcams]

@Quency-D @IoTThinks I flashed the firmware from the pre compiled firmware.

I'm not sure why Quency was telling me to run a python script? anyways, yes, thank you @IoTThinks, the cli commands work! I was going to try this first for sure.

Powered on 4.3 board, LNA on and repeater working normal. noise floor -103, transmit power +28.3 dbm.....working normally.

here we go-

"set radio.fem.rxgain off" give me a reply "OK - LoRa FEM RX gain off"
I can confirm that the LNA is OFF, noise floor dropped to -118
power draw dropped from 12.3mA down to 5.8mA (this is with powersaving on of course, its older version as we all know)
Transmit power remained at +28.3 :) very very nice Quency!!

now to turn back on LNA-

"set radio.fem.rxgain on" give me a reply "OK LoRa FEM RX gain on"
LNA is now on, power draw increase back to 12.3mA
Noise floor clamped instantly -120......tried agc rest command at 4, 8, 16.....no luck
So then I try reboot and success! noise floor -102

Conclusion-
This works!
Reboot is needed when turning the LNA back on, otherwise clamps to -120 even with agc at 4,8,16
Transmit power remains +28 both with LNA on and off