Keypad pin 4 to Arduino digital 8 //R4; Keypad pin 5 to Arduino digital 4 //C3; Keypad pin 6 to Arduino digital 7 //R3; Keypad pin 7 to Arduino digital 6 //R2; Since keypads are available from many ...

But we can’t deny this Arduino calculator project by [Danko Bertović] ... [Danko] is using an array of 17 tactile switches for the keyboard and a very crisp 128×32 I2C OLED display.

You don’t have to have high-quality parts to play around with electronics and here’s a great example. [Vishal] used junk to play around with CapSense, the touch sensitive Arduino librar… ...

The Gesture Keyboard is a device that translates gestures into letters. It’s made by an Arduino Pro Micro, an HC-06 module for Bluetooth communication, and an MPU-6050 accelerometer.