LED Bar Graph Power Display - MAX7219

Three simple PCB's with 7-segment displays and an LED bar graph. Also included is a speaker and driver for alert tones.

The three versions

• Type B is a general purpose display with power and signal connections available via a 10 pin header.
• Round is based on the above display but has has more bar LED's and is round.
• Type C is based on the above display but has connectors on the back for a Wemos D1 Mini WiFi board.

Included are a couple of demo sketches one for each display board. Below are the libraries used in these sketches.

• Library for the MAX7219 display driver https://github.com/Mottramlabs/MAX7219-7-Segment-Driver
• Library for driving the speaker on the ESP8266 (used for Wemos D1) https://github.com/Mottramlabs/ESP8266-Tone-Generator

The boards were designed to display house mains power usage but may have many other uses.

Bar Graph Display Type B - General Purpose Connections

Bar Graph Display Round Type

Bar Graph Display Type C - Wemos D1 Mini Version