Will esp32-s2 be supported

[kluoyun]

Alternatives for soc/mcpwm_reg.h: []
ResolveLibrary(soc/mcpwm_reg.h)C:\Users\23398\Documents\Arduino\libraries\Simple_FOC\src\drivers\hardware_specific\esp32_mcu.cpp:6:10: fatal error: soc/mcpwm_reg.h: No such file or directory

-> candidates: [] #include "soc/mcpwm_reg.h"

      ^~~~~~~~~~~~~~~~~

compilation terminated.

Changing the board to esp32 can compile normally, and esp32s2 fails

[runger1101001]

Compared to the previous ESP32 chips, the ESP32-S2 does not have the MPWM (motor PWM) peripheral.

It has the LED_PWM, so in theory we could probably support a basic 3-PWM mode, but it would be difficult to support all the features in the way the previous chip does.

Currently, I assume the ESP32 hardware specific code does not account for these chip generation differences. Certainly we should make it compile cleanly (and at least support generic PWM).

[runger1101001]

Thanks for reporting it, @kluoyun

[JimAllanson]

I've run into the same issue trying to compile for ESP32-C3.

[runger1101001]

Yeah, unfortunately the product number are quite confusing, additionally complicated by the fact that there are chip product number and module product numbers. Whether MPWM is supported depends only on the chip that is on the module.

These ESP32s have MPWM:

ESP32-D0WD-V3
ESP32-U4WDH
ESP32-S0WD
ESP32-D0WD – Not Recommended for New Designs (NRND)
ESP32-D0WDQ6 – Not Recommended for New Designs (NRND)
ESP32-D0WDQ6-V3 – Not Recommended for New Designs (NRND)
ESP32­-PICO­-D4

These ones have no MPWM:

ESP32-S2
ESP32-S2FH2
ESP32-S2FH4
ESP32-S2FN4R2
ESP32-S2R2
ESP32-C3FN4 (ESP32-C3-MINI-1, ESP32-C3-MINI-1U)

That's a quick search, this list may not be complete.

[JimAllanson]

With the ESP32-C3 (I'm not using the C3FN4, though this seems identical besides integrated flash), I'm also seeing an error for a missing soc/rtc_io_reg.h and soc/sens_reg.h from the current sense driver. I'm not using current sensing on my board, so I could probably strip this out for my use case.

I had a brief look at what it would take to fall back to a method that supports the ESP32-C3 in the esp32_mcp.cpp driver. I was hoping that I might be able to get away with reusing the ESP8266 implementation that just uses the built in Arduino analogWrite and analogWriteFreq functions. Unfortunately, these don't seem to be implemented in the Arduino framework when targeting the C3.

I took a look at the ESP-IDF LED Control example here which seems relatively straightforward, so I might take a crack at trying to get something with it on the C3. I don't think I know enough about ESP-IDF or how the missing functionality from MCPWM is used in the library that I could contribute a PR with support yet though.

[JimAllanson]

I got a very naive implementation working on my C3. I was just trying to prove the concept so it's not optimised, and it's currently just forcing 5khz as there's some nuance around duty cycles / frequency that I haven't fully looked into yet. I'll keep tweaking it and submit a PR if I get it a bit more production ready, but for now here's a link to my implementation for anyone who wants a jumping off point.

https://gist.github.com/JimAllanson/8b1b8c5bfe5a20862e0c0c77272bb86c

[runger1101001]

That looks pretty awesome!

A couple of comments:

1. I see you stayed away from the analogWrite() - that's good, the generic PWM driver would do that anyway... much better to use the ledpwm calls like you did.

2. I think 3-PWM will work just fine. 6-PWM is a different story. Each hi and lo side PWM need to be perfectly synchronized, with the possibility for "dead time" insertion. Otherwise the FETs could be switched in a way that causes a short circuit. Additionally, to support low side current sensing, the three phases should also be in sync. This will only work if the PWMs are running off the same clock and all started synchronously... I really don't know if the LEDPWM does this or not.

I'm on holidays at the moment, but I have a feather ESP S2 board at home so when I get back I could try it out...

If it doesn't work well it might be better to stick to 3-PWM on these chips.

[askuric]

ESP32 s2 and c3 which do not have mcpwm are now supported from the v2.2.1