Firmware for ESP32-C3

[robostart-io]

Good day, dear Michael and creators of microlite!
Thanks for your wonderful project. This is a very handy item. It seems to me that his appearance is a very big event in the world of micropython.
Let me ask you, is it possible to create a firmware for the increasingly popular ESP32-C3 based on RISC-V?

[mocleiri]

At the moment I'm not building for all boards only the ones that people ask for and can verify. If you have an ESP32-C3 to test with I can add a build for it.

Normally I copy the board configs from micropython and then customize as needed for the microlite module. Which board config are you using?

[robostart-io]

We use the ESP-C3-M1 KIT 4M board to study microcontrollers and create educational projects.

ESP-C3-M1 KIT has a small width and length and can be installed on any solderless breadboard, even the SYB-170 mini. It has an RGB LED, which is convenient to use as a multi-color indicator without resorting to additional elements. At the same time, it is very cheap and quite powerful.

We are programming in MicroPython using a programming environment I made for learners and beginners. Now I'm making a variant for Linux. You might also like this IDE.

micropython/micropython#9333

I would be very grateful if you could build a microlite for this board. My students also join my gratitude.

[mocleiri]

I've started work on this but the build isn't quite working yet. You may also want to take a look at https://github.com/espressif/tflite-micro-esp-examples

Which is Espressif's tflm repository, the only downside is you have to compile using C/C++ instead of using micropython.

The C3 is only a single core so you may need the acceleration library integrated there to get acceptable speed.

Its a work in progress to get the esp_nn library merged into this repo. I tried a few months ago but it locked up my normal esp32's when trying to run inference and I haven't been back around to try again.

[robostart-io]

Thank you so much for getting started!
Unfortunately, working with ESP-IDF is problematic for many reasons for beginners.
So far, we are using your build for a regular ESP32 under MicroPython and are very happy with it.
We are ready to wait as long as necessary, and will make every effort to test and debug it.
Thank you very much again.

[robostart-io]

I thought how I could be useful to your project? Decided to make a logo for it.
Logo for Tensorflow Micropython Examples

[uraich]

Hmmm, Link does not work for me.

[robostart-io]

Sorry, added access

[mocleiri]

@robostart-io my latest change built the firmware successfully. Can you download the applicable zip from here: https://github.com/mocleiri/tensorflow-micropython-examples/actions/runs/3662193220

You have to unzip the file and then flash using the different parts. This comment shows how the bits in the zip file can be combined into a flashable .bin file:

#99 (comment)

There are a couple of more changes needed for the other ports before this work will merge down into the main branch. But you should be able to confirm if the build is producing working firmware or not.

[robostart-io]

Tried to flash from https://github.com/mocleiri/tensorflow-micropython-examples/actions/runs/3666469707 and https://github.com/mocleiri/tensorflow-micropython-examples/actions/runs/3662193220

by using esptool-4.4:

python esptool.py erase_flash

python esptool.py -p COM6 -b 460800 --before default_reset --after hard_reset --chip esp32c3 write_flash --flash_mode dio --flash_size detect --flash_freq 40m 0x1000 bootloader/bootloader.bin 0x8000 partition_table/partition-table.bin 0x10000 micropython.bin

Connected and got a constantly repeating string

invalid header: 0xffffffff

Sometimes the following messages appear:

invalid header: 0xffffffff                                                                         
invaliESP-ROM:esp32c3-api1-20210207                                                                
Build:Feb  7 2021                                                                                  
rst:0x10 (RTCWDT_RTC_RST),boot:0xc (SPI_FAST_FLASH_BOOT)                                           
invalid header: 0xffffffff 

...

invalid header: 0xffffffff                                                                         
invalid headeюESP-ROM:esp32c3-api1-20210207                                                        
Build:Feb  7 2021                                                                                  
rst:0x7 (TG0WDT_SYS_RST),boot:0xc (SPI_FAST_FLASH_BOOT)                                            
Saved PC:0x4004d1f8                                                                                
invalid header: 0xffffffff

...

invalid header: 0xffffffff
invalid header: 0шESP-ROM:esp32c3-api1-20210207                                                    
Build:Feb  7 2021                                                                                  
rst:0x10 (RTCWDT_RTC_RST),boot:0xc (SPI_FAST_FLASH_BOOT)                                           
invalid header: 0xffffffff

...

After turning off the power and turning it back on, the COM port does not respond and does not output anything.

[mocleiri]

Can you try flashing at a slower baud rate? Sometimes that can help.

I found this esp-idf issue that had the same error message which might help: espressif/esp-idf#9005

[robostart-io]

Erased without problems

python esptool.py erase_flash
or
python esptool.py -p COM13 --chip esp32c3 erase_flash

PS H:\Electron\esptool\esptool-4.4> python esptool.py erase_flash
esptool.py v4.4
Found 2 serial ports
Serial port COM13
Connecting....
Detecting chip type... ESP32-C3
Chip is ESP32-C3 (revision v0.3)
Features: WiFi, BLE
Crystal is 40MHz
MAC: 34:b4:72:4d:cf:fc
Uploading stub...
Running stub...
Stub running...
Erasing flash (this may take a while)...
Chip erase completed successfully in 16.2s
Hard resetting via RTS pin...
PS H:\Electron\esptool\esptool-4.4> python esptool.py -p COM13 --chip esp32c3 erase_flash
esptool.py v4.4
Serial port COM13
Connecting....
Chip is ESP32-C3 (revision v0.3)
Features: WiFi, BLE
Crystal is 40MHz
MAC: 34:b4:72:4d:cf:fc
Uploading stub...
Running stub...
Stub running...
Erasing flash (this may take a while)...
Chip erase completed successfully in 16.1s
Hard resetting via RTS pin...
PS H:\Electron\esptool\esptool-4.4>

I tried changing speed on 115200 yesterday

Today I tried even lower, up to 10000 (at 9600 the esptool refuses to work with ESP32c3).

PS H:\Electron\esptool\esptool-4.4> python esptool.py -p COM13 --chip esp32c3 er
ase_flash
esptool.py v4.4
Serial port COM13
Connecting....
Chip is ESP32-C3 (revision v0.3)
Features: WiFi, BLE
Crystal is 40MHz
MAC: 34:b4:72:4d:cf:fc
Uploading stub...
Running stub...
Stub running...
Erasing flash (this may take a while)...
Chip erase completed successfully in 16.2s
Hard resetting via RTS pin...
PS H:\Electron\esptool\esptool-4.4> python esptool.py -p COM13 -b 10000 --before
 default_reset --after hard_reset --chip esp32c3 write_flash --flash_mode dio --
flash_size detect --flash_freq 40m 0x1000 bootloader/bootloader.bin 0x8000 parti
tion_table/partition-table.bin 0x10000 micropython.bin
esptool.py v4.4
Serial port COM13
Connecting....
Chip is ESP32-C3 (revision v0.3)
Features: WiFi, BLE
Crystal is 40MHz
MAC: 34:b4:72:4d:cf:fc
Uploading stub...
Running stub...
Stub running...
Configuring flash size...
Auto-detected Flash size: 4MB
Flash will be erased from 0x00001000 to 0x00004fff...
Flash will be erased from 0x00008000 to 0x00008fff...
Flash will be erased from 0x00010000 to 0x001fafff...
Compressed 15984 bytes to 10208...
Wrote 15984 bytes (10208 compressed) at 0x00001000 in 10.6 seconds (effective 12
.0 kbit/s)...
Hash of data verified.
Compressed 3072 bytes to 115...
Wrote 3072 bytes (115 compressed) at 0x00008000 in 0.2 seconds (effective 115.4
kbit/s)...
Hash of data verified.
Compressed 2008688 bytes to 1204669...
Wrote 2008688 bytes (1204669 compressed) at 0x00010000 in 1216.8 seconds (effect
ive 13.2 kbit/s)...
Hash of data verified.

Leaving...
Hard resetting via RTS pin...
PS H:\Electron\esptool\esptool-4.4>

Changed the cable. Changed the board with ESP32c3. Сhanged computer. Changed the terminal program. The result is the same.

Yesterday I wrote: "After turning off the power and turning it back on, the COM port does not respond and does not output anything". This is not entirely true. After turning off the power and turning it on again, the port in some cases receives a constantly recurring invalid header: 0xffffffff.

How else could I test to help make the build?

[robostart-io]

I used two types of boards for testing

ESP-C3-M1-Kit

ESP-C3-32S(4M)-KIT

[robostart-io]

I tried with old versions of esptool, but I get it again invalid header: 0xffffffff.

[mocleiri]

What board config do you use from micropython? For the microlite C3 images I am building directly from the micropython GENERIC_C3 and GENERIC_C3_USB configurations.

To troubleshoot I just made a new image for the esp32s2 as I do have this board https://docs.espressif.com/projects/esp-idf/en/latest/esp32s2/hw-reference/esp32s2/user-guide-devkitm-1-v1.html

Mine got stuck at the power on step until I removed the usb configuration as this dev board has the serial chip. Have you been flashing the generic_c3 image?

[robostart-io]

For C3 I used a GENERIC_C3.
I'm flashing the microlite-esp32c3-firmware.

On the page https://micropython.org/download/esp32c3/ with the firmware for esp32c3 it says

From then on program the firmware starting at address 0x0

Maybe that's the problem?