RP2040 internal temp as telemetry, fix TCXO voltage. Create New variant Pico Hat for SX1262

[thomasabbott]

Two in one:

1a) Adding telemetry for the RP2040 internal temperature sensor on the waveshare RP2040 lora board.
1b) Fixing the TCXO voltage which can't be zero in RadioLib 7.3.0. Left in some MESH_DEBUG prints used to diagnose this. This may fix #1109.
Not tested on hardware.

2. New variant for the Waveshare SX1262 LoRa Node Module for Raspberry Pi Pico cloning the Waveshare RP2040 Lora and changing the GPIO pins.

Tested pico_hat_sx1262_companion_radio_usb and pico_hat_sx1262_repeater on hardware:

• New temperature telemetry is reported correctly (within the limits of the sensor, so +- 5 degrees)
• on-board LED flashes for LORA Tx

[recrof]

we already have rpi pico w and waveshare rp2040 in variants, is this something different?

also - we use internal temperature sensors for esp32 and nrf52, would be good to use same way of doing things across platforms: #1206

[JDat]

Not sure about new variant, but other thing looks OK. I am also working with RP2040. I want to add SPI selection/config for RP2040 and powersaving by downclocking RP2040 to 12 MHz. Next thing is to experiment with RP2040 sleep modes. All these changes/additions can be done on PicoW variant for now.

[thomasabbott]

@recrof thanks for reading. In order of priority:

Moving to the new radiolib exposed a mistake in the waveshare RP2040 lora variant - the sx1262 TCXO voltage can't be zero, then the radio fails. This fixes #1109 - someone's tested it. Should I rather submit this as a stand-alone PR?

we already have rpi pico w and waveshare rp2040 in variants, is this something different?

The new variant is different to the all-in-one waveshare board - it's a hat for the regular Pico, with the SX1262 connected to different pins, and a battery voltage monitor. It's not currently a variant (though there is working community firmware on the web flasher).
vs
Is there a more elegant way to do this? I think it's a fully qualified variant, but it could be crammed into the same platformio.ini as the original waveshare all-in-one. What's best here?

also - we use internal temperature sensors for esp32 and nrf52, would be good to use same way of doing things across platforms: #1206

OK I see what was done in #1206, my way is not as general. Shall I rewrite my sensor to fit into this style, so mymesh.cpp can just call float temperature = board.getMCUTemperature(); for RP2040 boards too?

[recrof]

The new variant is different to the all-in-one waveshare board - it's a hat for the regular Pico, with the SX1262 connected to different pins, and a battery voltage monitor. It's not currently a variant (though there is working community firmware on the web flasher).

we already support waveshare board with plain old picow - https://github.com/meshcore-dev/MeshCore/blob/main/variants/rpi_picow/platformio.ini

OK I see what was done in #1206, my way is not as general. Shall I rewrite my sensor to fit into this style, so mymesh.cpp can just call float temperature = board.getMCUTemperature(); for RP2040 boards too?

Yes

[thomasabbott]

Thanks @recrof . Closing this one now.

[JDat]

@thomasabbott can you make internal temperature as separate thing for PicoW ?