A modular board hosting 9 seven-segment displays that can be daisy chained to make an art installation
The tile software is now working on a Sinclair Calculator.
Since there are no current limiting resistors on the board, the software is being developed on a calculator. Once it is debugged and the displays arrive, it will be uploaded to a production board.
At Art Basel Miami Beach 2018, I saw an art installation that consisted of seven-segment displays hanging from the ceiling. Some of the displays changed.
The artist name is Tatsuo Miyajima, some of his art installations can be seen below. He specializes in using seven-segment displays.
This got me thinking. An Arduino Nano can drive 9-10 Seven-Segment Displays in a multiplexed arrangement. Up to 11 displays can be driven if one does not connect the decimal point.
A board size of 100x100mm can comfortably fit 9 0.56" (13mm wide) displays and an Arduino Nano to control them.
The boards will be networked using two 3-pin headers. The header carries power, ground and a serial port signal. The header on the left connects the serial port to the receive (RX) pin on the Arduino Nano, and its TX pin is connected to the header on the right. This way, each Arduino in the chain receives commands from an upstream device and sends them to the next device.
The first board will have two Arduinos soldered, the first one holds the instructions to light up the digits in the whole installation and it sends serial commands to the other Nano in the same board, this Arduino will light up the LEDs and forward the rest of the commands down the line to the other boards.
This project is designed for manufacturing, the board size is selected to take advantage of price specials, Only three components are used, an Arduino Nano, seven-segment displays and a three-pin header. All of the components are through hole. The only other components needed are jumper cables to connect the boards, standoffs, a piece of wood or plexiglass to mount the boards, and a power connector.
A board was quickly designed in Fritzing. The front layer has a minimal amount of vertical lines, the rest of the traces are in the back. All of the vias are hidden under the displays.
The board gerbers were exported and uploaded to PCBWay Gerber viewer.
I really like the new version of the tool, the board can be zoomed in to identify problem areas. PCB layers can be turned on and off and it renders the board in the production colors.
The board will be manufactured in Red, to match the color of the seven-segment displays linked below:
The front side of the board is very minimalist, no marks whatsoever, vias hidden under the displays and a minimum of copper showing. The design is symmetric.
The back has a few markings and a little more copper visible.
Parts have been ordered. Stay tuned for part two...
You can also follow this project on Instagram: