The ESP32 devkit v1 and alike ESP32 boards have 25 usable GPIO pins exposed, many of which are input only pins (4 pins which can only be used as digital input pin), many are strapping pins (5 pins which are used for boot control and should not be se…
Usually if we want to use Arduino with 16x2 LCD to display some message, usually 6 I/O pins of Arduino are required as illustrated in the blog post Arduino Keypad and LCD Interfacing with Code . However, sometimes we need those I/O pins for interf…
Here it is shown how to expand Arduino's I/O using MCP2307 I/O expander IC with example of a button-controlled LED. The MCP2307 is a 16-bit input/output (I/O) expansion chip manufactured by Microchip Technology that can be used to add extra inpu…
