Monday, April 20, 2015
Adapting an ESP-01 module for breadboard use
While esp8266 ESP-01 modules can easily be programmed after hooking up some dupont jumpers to a USB-TTL module, using them on a breadboard without an adapter or modification is not possible. The obvious method of making an adapter with a 2x4-pin female header, some stripboard, and 2 1x4 male headers. I thought of an even simpler way of adapting the ESP-01 for a breadboard without using any extra parts.
Of the 8 pins on the ESP-01, the CH_PD pin should be permanently tied to Vcc, so only 3 of the four middle pins are needed. If you use my zero-wire reset solution, only the GPIO0 and GPIO2 pins are needed. To modify the ESP-01 for breadboard use, heat up the CH_PD pin with a soldering iron, then pull it out with a pair of needle-nose pliers after the solder is liquid. Then solder a short wire from Vcc to the CH_PD pad. Next heat up the remaining 3 middle pins, and push them until they stick up out of the PCB. To do this I put my needle-nose pliars under the pins, then pushed down on the module. If you go too fast and get lumps of solder on the pin, add some flux and heat up the solder to level out the solder so jumper wires can smoothly plug into the pins. If you're not using my reset solution, I still recommend a capacitor on RST as it will reduce or eliminate spurious resets. The RST line on the esp8266 is very sensitive, at least compared to RST on 8-bit AVR MCUs. When you are done you your module should look like one below, and can easily plug into a breadboard.