VKey Voltage Keypad

Product Code: 1421
by SparkFun
£12.77 inc VAT
£10.64 ex VAT
1 in stock.

More available in 3-5 days.
Available for backorder (more info)

This is the VKey Voltage Keypad, a simple board that adds a keypad to your microcontroller project without using multiple I/O pins. This keypad has 12 pushbutton switches in a 3x4 array. The VKey operates by outputting an analogue voltage to encode which key has been pressed, which can be read by an analogue to digital converter on a microcontroller on a single input pin.

Traditional digital keypad interfacing techniques can require a large number of digital I/O lines. On a small controller, there may not be many I/O pins left for other tasks. The VKey operates at a voltage of 3.3-5.5V and features a dual opamp which is used as a current source and buffer amplifier.

Note: This is a partial kit that requires the push buttons to be soldered onto the board.