ESP8266 WiFi support

[sh0rez]

The docs (https://tinygo.org/microcontrollers/esp8266/) list that the ESP8266 WiFi feature is not supported by TinyGo.

Imo having this support is crucial for this board to make sense. What needs to be done so this can happen?

[vertoforce]

Just wanted to comment and say how grateful I am for the tinygo project. I am truly terrible at c++, and I don’t like writing It, but I resonate with go. I’m really excited to do a project with an ESP chip and tinygo.

WiFi support would is HUGE. If I’m capable I’d be happy to help make it happen. But a major +1 to this request.

[vertoforce]

Unless, is it the case that we can use this driver to get WiFi functionality?

[vertoforce]

It looks like theoretically you could use one esp8266 to control / use wifi over another esp8266 (over UART). The first esp8266 would use this driver to talk to the second esp8266 with the AT firmware (listed on driver's README).

Because I really want to write go on the esp8266, and because they are cheaper than something like the arduino nano 33 IoT, I may actually do this. I'll post code if I do.
Then I can always swap it out when tinygo supports the esp8266 wifi.

[aykevl]

Imo having this support is crucial for this board to make sense. What needs to be done so this can happen?

Yes, I totally agree.
One of the first things is probably to get compiler-rt and picolibc to compile. They do appear to compile in the latest version of the Xtensa fork (Espressif pushed some bug fixes) but when testing the chip (at least the ESP32, didn't test the ESP8266 yet) the chip seems to hang.
Debugging this would be much easier with a proper debugger. I've ordered a FT2232 board to act as a JTAG debugger, so I should be able to see what's going on in a few weeks.

Also, for networking to work we'll also need:

• interrupt support
• a network goroutine/task (probably)

In other words, it'll require some low-level development.
If you would like to dive deep, you're very welcome to help out :)

[aykevl]

Update: compiler-rt and picolibc are now available. But many things are left to do.

[tobiaskohlbau]

@aykevl I've looked into this a few weeks ago. I've also compiled compiler-rt and picolibc without problems. One problem I ran into was that by the looks of it, at least the ESP32, does not have the ability to run without the RTOS. As far as I understand the current tinygo implementation does not leverage any of the RTOS based SDK. I've looked into options to link against some sort of libraries as possible with the non RTOS version of the ESP8266 development kit but did not succeed. And I found that Espressif discontinued the non RTOS based SDK for the ESP8266 as well. It receives some sort of bugfix update but the users are encouraged to use the RTOS based SDK.

If this is the right observation, are you aware of this situation and maybe have some ideas to overcome this?

[aykevl]

One problem I ran into was that by the looks of it, at least the ESP32, does not have the ability to run without the RTOS.

I think we can use the TinyGo scheduler as the RTOS, but I haven't looked into this yet. Using FreeRTOS in TinyGo would be very complicated.

[tobiaskohlbau]

Thats the point, embedding FreeRTOS into TinyGo is not the right path to enter. Espressif supplies some kind of libraries at https://github.com/espressif/esp32-wifi-lib/tree/master/esp32. On my first look this libraries also depend on FreeRTOS and their SDK. I was hoping to find some low level APIs, within the libraries, which allows interacting with the wifi system.

IMHO I would like to reuse as most network logic from the standard library of go as possible. But it looks like Espressif is not willing to support such setups. Is TinyGo currently running on a single core in ESP32 setup?

Looks like at least for the ESP32 there is an option to get full access to the coprocessor.
https://github.com/espressif/esp-idf/blob/master/components/freertos/Kconfig#L4

[aykevl]

It appears that RIOT has managed to run its RTOS on the ESP8266, with WiFi support: https://doc.riot-os.org/group__cpu__esp8266.html

I think we should look into how they do it.

[tobiaskohlbau]

Thanks for the reference!
I was not ware of the existence of riot. I've looked into micropython and low.js. Micropython uses the FreeRTOS from Espressif and low.js has the part about ESP32 not opensource.

[mamoit]

I just watched this Hackaday talk by Uri Shaked (@urish) that may be a way in for the development of an open source driver:
https://hackaday.com/2021/12/30/remoticon-2021-uri-shaked-reverses-the-esp32-wifi/

[tobiaskohlbau]

I also watched that talk and was inspired to have another look into this. Maybe I find some time to dig into the internals again.

Thanks for bringing this up again.

is there any update on the use of WiFi for nodemcU?

thanks