Enabling full 32MB flash on ESP32-S3-DevKitC-1-N32R8 development board

[wbeebe]

I have a local development system with the following characteristics:

• Linux Mint 22.1
• ESP-IDF 5.4
• MicroPython 1.25.0 pre-release locally cloned and kept up-to-date from the MicroPython repo

So far the latest MicroPython pre-release builds, flashes and executes without issues on the ES32-S3 dev boards. My only "complaint" is trying to determine how to configure/enable the MicroPython tools to enable the entire 32 MB of flash on the board. Right now all I can see is 8 MB. If I program the board in C++ using ESP-IDF 5.4, I can see and use the entire 32 MB. I would like to be able to do this with MicroPython.

Is there a good how-to or blog post that clearly documents how to accomplish this?

Thank you.

[scruss]

maybe mp-image-tool-esp32 could help here. It allows you to reconfigure flash allocation. Some past discussion/examples here: Issue with Accessing Full 16 MB Flash on ESP32 with MicroPython · micropython · Discussion #15315

[wbeebe]

Thank you, I'll take a look.

[wbeebe]

Tried to install mp-image-tool-esp32 via pip in a Python 3.13.2 virtual environment (I build my own latest Python releases). It failed to install because littlefs-python and cryptography failed to build. The chain of failures started with littlefs-python. It looked like gcc was called and I have 13.3.0 installed. It also looks like it was trying to build something in Rust; there are cargo:warning messages through a good part of the failure output. I have Rust 1.84.1 installed.

It's late here and I'm turning in for the evening. I'll look at it a bit more tomorrow.

[wbeebe]

I next tried the clone-from-GitHub installation recommendation along with using uv. I used uv to build and install mp-image-tool-esp32. That, too, was successful. I would strongly suggest that you edit the README to only use uv for building and installing mp-image-tool-esp32. Using pip is a disaster.

Now on to using mp-image-tool-esp32.

[wbeebe]

First test for mp-image-tool-esp32 was to read one of my ESP32-S3-DevKitC-1-N32R8 boards, which it did. Here's a typical output.

I like the information layout. In particular I like that it flagged, in yellow text, that it found the 32MB of flash along with the helpful suggestion on how to increase the size to the maximum.

A recommendation: In the README please show an example that explicitly uses the device (/dev/ttyUSB2 in this example), rather than just calling out a 'file'.

[scruss]

Using pip is a disaster

Yes. All self-inflicted by Python, too. I now use pipx where I can

[wbeebe]

And it works. Here's another example.

And here's where I ran my simple web server on the development board. This was a screen capture using a Pixel 4a running Android 13 as a test device.

Note at the bottom that the MicroPython code running on the dev board has found 32MB of flash (it's in bytes). Before I ran mp-image-tool-esp32 it would only show 8MB of flash.

mp-image-tool-esp32 is an excellent application. Thank you again for your timely answer and for creating this tool.

[scruss]

You want to thank @glenn20 — I'm only a satisfied user