ESP-01 Modding to More GPIOs

Enhance the cheap ESP-01 module with 2 more GPIOs

The ESP-01 is a cheap ESP 8266 module with the advantage over other modules, that it has a connector which is compatible with standard 2.54mm (1/10'') headers.

It can easily be programmed with programmers like the one shown on the picture.

It lacks some decent GPIOs though, which renders it less suitable for many applications compared to an ESP-12 module, but with some soldering it can be extended to 2 more GPIOs quite easily.

To achieve this, I first cut out a 4x2 piece from a hole matrix PCB and soldered it on top of the ESP-01 header as shown on the introducing picture.

At the non-overlapping end, I attached a 2-pin header for the 2 more GPIOs.

The GPIOs I used are the most versatile GPIOs of the ESP-8266 chip, and they are fortunately quite easily to connect as they are the last in row on 2 corners of the chip.

In contrast to most other pins, GPIO 4 and 5 don't show any jitter during power up and thus are best suited to drive outputs like relays.

I successfully used my ZD-981 60W soldering iron with a 0.5mm tip to have enough power to connect the wires to the ESP pins.

After soldering, I did put some hot glue on the wires to add some protection, but this not a necessary step.

The scheme could be further enhanced to add even more GPIOs, but for those, soldering can become rather tricky.