ESP32 S3 - USB Serial JTAG Console not Support in current code

[SimonGAndrews]

There seems to be an issue in that the ESP32S3 build does not include support for the USB Serial JTAG Console. That is boards where the USB connector (for connection to the host/IDE) is routed directly to the processor (GPIO 19/ D+ and 20 / D- ) and not through a USB to Serial Convert chip to 43/U0TXD and 44/ U0RXD.

The symptom is no response in the IDE after flashing. The espressif monitor confirms flashing is ok and the espruino banner displays after a reboot, but then no console/repl.

Ive seen other forum posts that indicate the same.

In the current code ../targets/ESP32/jshardwareUart.c handles this for the ESP32C3 but the #ifdef in the code does not include the S3. Ive thad a go to fix in threee places:

Which has improved in that I get a console now. But it now has the problem seen during the initial port where there is no echo till enter key is pressed.

I Also note the need to define USB_CDC in board.py, whcih ive done. And it looks to be set in the IDE.

WIll keep going to figure it out, but I cant initially see where to fix the Echo, given it was fixed in the C3.

[gfwilliams]

Thanks for looking into this! IIRC Espruino was getting the data as written and processing it, but the data was only being sent out to USB after a newline. I'm pretty sure this was the code (esp32USBUARTWasUsed), so hopefully a check for ESP32S3 in there too would fix it:

https://github.com/espruino/Espruino/blob/master/targets/esp32/jshardware.c#L595-L599

[gfwilliams]

I think you need it here too: https://github.com/espruino/Espruino/blob/master/targets/esp32/main.c#L47-L51

[SimonGAndrews]

Ok there are three places in main Looks like need the change :

Are we ok just to check ?
#if defined(CONFIG_IDF_TARGET_ESP32C3) || defined(CONFIG_IDF_TARGET_ESP32S3)

Or should we check for JTAG Serial use also ie
#if (defined(CONFIG_IDF_TARGET_ESP32C3) || defined(CONFIG_IDF_TARGET_ESP32S3)) && defined(USB_CDC)

But this may be more usefull going forward:
#if (ESP_IDF_VERSION_MAJOR >= 4) && defined(USB_CDC)

[SimonGAndrews]

Sorry one more consideration:

does @MaBecker , @gfwilliams or anyone object to changing USB_CDC to USB_SERIAL_JTAG
In board.py and throughout.
Arguably more intutive and but is in line with the ESPIDF config whcih provides these thre config parameters

CONFIG_ESP_CONSOLE_USB_SERIAL_JTAG
CONFIG_ESP_CONSOLE_USB_CDC 
CONFIG_ESP_CONSOLE_UART

and then our condition becomes
#if (ESP_IDF_VERSION_MAJOR >= 4) && defined(USB_SERIAL_JTAG)

I would test throughout on c3, s3 with and without Jtag and on ESP32

---

Im not suggesting to use these ESPIDF configs now , we stick witth the def in board.py , But see this example for how we could look in the future.

CONFIG_ESP_CONSOLE_USB_CDC is USB OTG configuration for the console. See here

[gfwilliams]

#if (ESP_IDF_VERSION_MAJOR >= 4) && defined(USB_CDC)

Sounds good to me. Is this IDF4+ specific, or is it for devices with USB built in though? Eg would it work for ESP32_IDF4 where it's just an ESP32 on IDF4? Might be worth having something in platform_config (built with build_platform_config.py) which was just ESPR_SERIAL_JTAG or something?

anyone object to changing USB_CDC to USB_SERIAL_JTAG

I'm fine to change it, but personally I'd like to change the polarity to something like ESP_FORCE_NO_USB_SERIAL or similar.

I feel like the vast majority of ESP32C3/S3/etc are going to have serial over USB - that's one of the great things of the chip. It should really be opt-out IMO

[SimonGAndrews]

ok that would work - so im testing based upon this - but any feedback shout

Condition for logic
#if defined(CONFIG_ESP_CONSOLE_USB_SERIAL_JTAG) && !defined(ESP_FORCE_NO_USB_SERIAL)

and

Setup in board.py

and using ESP menuconfig to set CONFIG_ESP_CONSOLE_USB_SERIAL_JTAG on the appropriate targets config file. Eg targets/esp32/IDF4/sdkconfig_s3

which builds the config as

[gfwilliams]

That looks excellent, thanks! Way better being able to use something SDK-defined!

[SimonGAndrews]

@MaBecker , hi are you ok with this approach?

[MaBecker]

Yes, go - thanks for your effort

[SimonGAndrews]

Having tested changing parameters in the SDKConfigs to identify target boards uisng the ESP_CONSOLE_USB_SERIAL_JTAG im not going to include that in the solution. The available SDKCONFIG parameters were not working well in in the cases we are trying to override to use the USB to Serial conversion chips.

Instead im proposing to use a macro in the targets/ESP32/JShardwareUart.h like this

and a test condition in the the code
#if TARGET_PROVIDES_USB_SERIAL_JTAG && !defined(ESP_FORCE_NO_USB_SERIAL_JTAG)

It does mean the Espruino code will need to be modified if another board comes along with the USB_SERIAL_JTAG functionality. But it will only need changing in the one place instead of the eight places in three different files where the condition is used.

The Boardfile.py changes as follows are working fine:

Testing notes and PR to follow

[SimonGAndrews]

@gfwilliams / @MaBecker the port name for flashing changes with the new override as expected.

I can see that scripts/get_makefile_decls.py ESP32C3_IDF4 output the ESP_FORCE_NO_USB_SERIAL_JTAG in /gen/CURRENTBOARD.make if defined.
I could modify the target makefile to put an if condition on the port setting ??