My First PCB: ESP-01 USB Programmer Piggyback Board

About this project

This is a small board that piggybacks on an ESP-01 module, and makes it easier for you to program the ESP8266 via a USB-to-Serial board.

Story behind the project

After an awesome and inspiring presentation by Adafruit at a Hardware Summit in Rome a few years ago, I became determined to create my own wearables. In order to do that, I have to start somewhere. I discovered a problem to solve when I wanted to program an ESP8266 module (ESP-01) via a USB-to-Serial adaptor.

According to the datasheet of ESP8266, the GPIO-0 pin should be grounded for the microcontroller to be in programming mode. However, these cheap USB-to-Serial adaptors from China don't offer a way to make that connection.

To use these adaptors, I would have to solder the connection myself. First of all, this doesn't look very nice. Secondly, after soldering the pins together, I wouldn't be able to use the ESP with the adaptor to run my software because the microcontroller will always be stuck in programming mode.

Solution

My solution to this is this little board, that will sit between the ESP-01 and the USB-to-Serial board. Using a jumper, one can switch between programming and normal mode easily without soldering any pins together. The board had to be thin, in order to sit between the two components. Therefore it was crucial to go for the 0.8 mm thick PCB with 2 oz of copper option at OSH Park. Have a look at the pictures of the PCB design below.

If you think this is too much text to digest, have a look at the demo video instead.