Add support for Heltec HRI-485-2

[serpent213]

The Heltec HRI-485-2 is a LoRa to Ethernet gateway with wide-range DC power input, packaged in a DIN rail case. Includes slots for SIM card and LTE modem.

MCU: ESP32 D0WDQ6
LoRa radio: SX1262
Ethernet PHYceiver: Realtek RTL8201F
Extra flash: GigaDevice GD25Q64C (64 Mbit)
RS-485 transceiver (not populated)

(4 layer board)

I'm not sure how to activate the RTL8201. It seems, Ethernet is tied more or less to a specific platform:

src/DebugConfiguration.h:113:10: fatal error: RAK13800_W5100S.h: No such file or directory

After removing the includes:

src/mqtt/MQTT.h:17:10: fatal error: EthernetClient.h: No such file or directory

If I'm not mistaken it should be enough to include ETH.h as part of the ESP32 Arduino library.

Related to #2107. I did not reverse engineer the board fully yet, but apparently Eth and LoRa are connected in parallel.

Thoughts?

[CLAassistant]

All committers have signed the CLA.

[petrkr]

I am not sure if LoRa module can be connected to those GPIO pins, as those pins are reserved for SPI Flash.

If you check wires, they are connected to ESP32 Pins around 28-33 which is used for SPI Flash.
Atleast I am not aware that you can share Quad Serial Flash interface with something else.

My guess from that 4 layer board is, that lora module will be connected around JTAG pins GPIO 12-14

Ethernet also has exact pins, which Can not be used to anything else around 20-26

[fifieldt]

@RicInNewMexico is working on some changes to separate generic ethernet support from the particular RAK module, which should help here.

[RicInNewMexico]

@RicInNewMexico is working on some changes to separate generic ethernet support from the particular RAK module, which should help here.

Well, what I'm currently working on is enabling more ethernet connectivity for ESP32 based devices, but it will still be relying upon the W5100/5200/5500 arduino ethernet library.

We haven't previously used the built in ethernet support because that would require implementing the entire TCP stack in firmware whereas the WizNet ethernet modules have an embedded stack.

Supporting ETH PHY's using the ESP32 built in ethernet support would take a much more in-depth rewrite of the existing DHCP/NTP/MQTT/API/WEB areas of the codebase.

I'm not saying that it isn't possible or that it won't happen at some point in the future. I'm just saying that I'm not the right guy for that kind of job because it's beyond my (limited) skill level.

[petrkr]

@RicInNewMexico is working on some changes to separate generic ethernet support from the particular RAK module, which should help here.

Well, what I'm currently working on is enabling more ethernet connectivity for ESP32 based devices, but it will still be relying upon the W5100/5200/5500 arduino ethernet library.

We haven't previously used the built in ethernet support because that would require implementing the entire TCP stack in firmware whereas the WizNet ethernet modules have an embedded stack.

Supporting ETH PHY's using the ESP32 built in ethernet support would take a much more in-depth rewrite of the existing DHCP/NTP/MQTT/API/WEB areas of the codebase.

I'm not saying that it isn't possible or that it won't happen at some point in the future. I'm just saying that I'm not the right guy for that kind of job because it's beyond my (limited) skill level.

Actually using esp-idf tcp stack is just about initilize eth module. I have it up and running... but nobody wanted help me with gui stuff, so i just made it 'ugly way' in my fork.

Use Arduino wiznet library is worst thing, what you can do. For first wiznet's tcp stack sucks and second you will lost support for other Ethernet chips, supported by esp-idf

Check my forkx which is using now PHY Ethernet, because meshtastic uses obsolete 2.x SDK without SPI Ethernet support.

[petrkr]

Check this https://github.com/petrkr/meshtastic-firmware/commits/olabboard/

That was all needed to make proof of concept of working Ethernet on esp32.

#2107 (comment)