"WeMos" ESP32 Notes

November 01, 2017

If you haven’t caught on to the ESP32 yet, you really should.

It’s a wonder of engineering. At ~$10 USD, you get 2.4ghz wifi b/g/n, Bluetooth LE, 9 capacitive touch pins, tons of IO, and a mega fast processor with more than enough room for your project in a wonderful little Arduino Compatible package.

After a little bit of setup, you are good to go! Alternatively, you can also run Micropython on it.

Thats it for ESP32 overview. These are my notes on 1 very specific ESP32 package.

The “WeMos” ESP32

According to this forum post, the “WeMos” labeled ESP32 is a knockoff re-branded D-duino-32.

Simply for my sanity, I’ll be referring to it as the WeMos ESP32, as its featured in the blatantly stolen branding.

This board features a OLED display right on the board, along with EN and BOOT buttons surface mounted.

My particular one also has a female JST header next to the micro USB port, which I assume is for a LiPo battery, although it is unclear if it is really for that.

The OLED is an SSD1306 in plain white with a resolution of 128x64 pixels. The driver library can be found here and a nice little inscrutables tutorial for getting setup can be found here.

The OLED display is driven over I2C, with SDA linked to pin 5, and SCL linked to pin 4.
The I2C Address of the display is at 0x3c

The wiring of I2C, being as it is hard wired into the board, and reversed from normal, makes addressing other I2C devices a bit more of a challenge. Currently im trying to setup a BME280 with it.

I will update this post over time with more notes on this cool little device as a find them.

Alexander Swensen

Written by Alexander Swensen who lives and works in Nashville, TN building useful things. Follow me on twitter or checkout my github.