Among the pending projects list is something related to IoT, the function is not clear yet, but the idea is to be able to monitor or control it from a phone app or from a browser. I was researching on the internet and saw a lot of projects with the ESP8266, so seeing all the community around this device I got encouraged to work with it and bought some ESP-01 modules.
Following a couple of guides, I connected the module to a breadboard and did some tests, I was surprised that I could program the ESP from the Arduino IDE. While working with the modules, I made a mistake in a connection and ended up damaging one of the modules. With the idea of avoiding this from happening again, I decided to design a PCB where it would only be necessary to connect the power and communication, without having to make bridges or disconnect cables to enable programming.
On the board, I included the connector for the ESP-01, a row of pins to connect the USB to serial converter, and two more rows to connect the board to the breadboard; I also added a 3.3V LDO regulator, the RESET and programming switches, and finally, I made a voltage divider (which can be bypassed with a bridge) to accept 5V signals on the RX port.
For the PCB fabrication, I wanted to try the OSH Park service, which offers three boards at a cost of 5 USD per square inch, in my case, the PCB was 1.19 in², so the total was 5.9 USD with free shipping. After placing the order, the PCBs took about 20 days to arrive, that time was between manufacturing and transportation, while the boards were arriving I bought the necessary parts to assemble them.
Soldering the surface mount components was easy because the passive elements are 0805 size, which I have worked with before. After assembling one of the boards and trying to program the ESP8622, it worked without a problem, it was only necessary to connect the power and communication signals.
The values and references of the components are in the download files, if anyone is interested in these PCBs, they can be purchased on the OSH Park page, three units for 5.9 USD.
If you have any questions, feel free to ask.