indiantinker's blog

Getting ESP32-C3 Super-mini to do ESP-NOW

SuperMini

These little boards have been catching my attention lately due to their compact form factor and impressive features. They remind me of the Adafruit Trinkets, which remain my most-used boards in projects.

So, I bought about 10 of these Super Mini boards for an art installation project that uses a Quasi Mesh network, which utilizes ESP-NOW.

They seemed cheap and good.

Rui wrote a nice guide to get started with them on his blog. I also used this nice pin map website for reference.

Everything worked as expected until I soldered some perfboards and added these superminis—then ESP-NOW suddenly stopped working.

I had already missed lunch and was about to miss dinner. Hyperfocus, they say, is problematic, I say.

It was quite concerning.

Four hours of getting gaslighted by a bunch of AIs and reading some GitHub discussions and reddit posts…

It is a thing when people and AI keep inventing reasons and fixes for why something is not working. Man (and woman) is such a rationalising being. But maybe we can question the premise?

The main issue: these boards have poor RF performance, making them unreliable with wireless features like ESP-NOW.

Mounting them on a perfboard only makes things worse. They work best when kept off other hardware, which is why you often see them hanging from a USB-C connector in videos.

So, I am sorry! If you can read this looking for a software fix. There is none. Just don't solder it on a perfboard, or like me, you can 3D print a carrier and then solder from the top.

IMG_4770

It works well with this setup.

IMG_4772

If you want to keep using these boards, I would recommend the following:

  1. Ideally, do not use them for networking things. Use them like the Adafruit trinkets for their GPIOs and for factor.
  2. If you want networking in this form factor, try XIAO from SeeedStudio.
  3. If you want cheaper options, try looking for an ESP32C3 board with an antenna, but prepare to get underwhelmed. Here are some bugs you can buy.
  4. If you are really hacky and want to make it work, you can try this mod.
  5. In my experience, for reliable wireless functionality, it is good to rely on boards that have a module rather than a chip. It comes certified, too, in most cases.

Hope this helps avoid some time-waste and you can enjoy your Christmas.

Cheers
Rohit