Monoshield

The Monoshield is an Arduino shield designed to act as a monome like device.

This shield makes it possible to independently control up to 64 LEDs (or an 8-digit display) and read a grid of up to 64 multiplexed buttons. When used with the supplied firmware, the shield implements the monome serial protocol and is compatible most software available for the monome64.

The Monoshield Eagle files and the Arduino firmware are available for download.

Specifications

The Monoshield uses the max7221 LED driver chip. It can source up to 100mA per LED and sink 500mA per LED, it does dimming and supports 8-segment displays. The multiplexed button grid of the Monoshield is read using a standard SIPO shift register, the 74164, in conjunction with a PISO register, the 74165.

Parts List

• max7221 - Digikey MAX7221CNG+-ND - Order Free Samples
• 74164 Serial Register - Digikey 296-8248-5-ND
• 74165 Serial Register - Digikey 296-8251-5-ND
• 100K Ohm Resistor Network - Digikey 4610X-1-104LF-ND
• 11.8k Ohm Resistor
• 0.1 uF Capacitors - Digikey 399-4151-ND
• Push Button - Digikey SW400-ND
• Female Header 6 pins - Digikey S7039-ND
• Male Header 3x2 pins - Digikey WM26806-ND
• Male Header 8x2 pins - Digikey A26529-40-ND

Monoshield - Monome

I built my Monoshield to be used as a monome clone. It was assembled using the Sparkfun LED 4x4 button pads with white LEDs from Digikey 160-1772-ND. The aluminum face plate was milled on a 3 axis CNC machine. Unfortunately it’s not possible to use used ribbon cables with IDE connectors for the LEDs and buttons because the Sparkfun LED 4x4 button pads use 6 4x1 connectors, which are not compatible with standard ribbon cable connecters. My solution was to use standard Molex connectors crimped by hand.