ESP32 Forum

Hi, good evening.

We are trying to flash a brand new ESP32-C3 super mini with whatever source code, for example WifiSCan. Current IDE is Arduino 1.8.19. and we are getting the following log for several runs:


Sketch uses 273196 bytes (20%) of program storage space. Maximum is 1310720 bytes.
Global variables use 10080 bytes (3%) of dynamic memory, leaving 317600 bytes for local variables. Maximum is 327680 bytes.
esptool.py v4.6
Serial port COM4
Connecting...Traceback (most recent call last):

File "esptool.py", line 37, in <module>
Chip is ESP32-C3 (revision v0.4)
File "esptool\__init__.py", line 1064, in _main
Features: WiFi, BLE
File "esptool\__init__.py", line 859, in main
Crystal is 40MHz
File "esptool\cmds.py", line 466, in write_flash
MAC: 24:58:7c:ae:f5:68
File "esptool\util.py", line 37, in flash_size_bytes
Uploading stub...
Running stub...
TypeError: argument of type 'NoneType' is not iterable
Stub running...
[4344] Failed to execute script 'esptool' due to unhandled exception!
Configuring flash size...
the selected serial port Configuring flash size...
does not exist or your board is not connected



Also we have tried several Arduino IDE settings, that have been checked several times, without luck For example, current Arduino settings are:

Board: "ESP32C3 DevModule"
Upload speed: "115200"
USB CDC on Boot: "Enabled"
CPU Frequency: "160 MHz (WiFi)"
Flash Frequency: "80 MHz"
Flash Mode: "QIO"
Flash Size: "4MB (32 Mb)"
Partition Scheme: "Default 4MB with spiff (1.2MB APP/1.5MB SPIFFS)"
Core Debug Level: "Verbose"
Erase All Flash Before Sketch Upload: "Disabled"
JTag Adapter: "Integrated USB JTAG"
Zigbee Mode: "Disabled"
Port: "COM4 (ESP32 Family Device)"
Get Board Info
Programmer: "Esptool"

Currently there are some updates around for Arduino libraries and boards. We have tried with and without these updates but no change.


Any clues/help to solve these issues are greatly appreciated. Thanks.

Note that you may need to put the unit into download mode the first time you flash it by holding the 'boot' and pressing the 'reset' button.

Also be aware that there's known dodgy ESP32-C3 Super-Mini boards out there; one of the dodgy types has a flash-less version of the ESP32C3 and no external flash. Suggest you check if that's the case (by checking the number written on the ESP32C3 chip and cross-referencing against the datasheet to see if it has embedded flash)

Thanks for your advice. We have found an Espressif report stating something similar to what you post and we are working on it. Thanks a lot for your help.

We have changed ESP32 MCU supplier, bought some chips from a different batch and they work as designed. Will keep buying from that supplier even though we know there is a chance the wrong chips may also arrive to our new supplier.