If you look around your desk now, you will most likely see one or two 7-segment displays that will show you some important information, such as the time or today’s weather.But think about how much information you can see with more than 1,100 digits, such as [Chris Comb’s] 7200 segment display.
for [Chris], This project started in the same way as many of our projects; find components that are too cost-effective to give up.With just “one or two songs plus shipping”, he proudly owns two boxes 18:88 7-segment display, a total of 500 modules. Instead of sitting and taking up valuable shelf space, [Chris] Decided to turn them into strange things that he could hang on the wall.
The first challenge is to try to signal all the individual market segments in some way. There are solutions for running a few displays in one device, but there is certainly no off-the-shelf solution for so many displays.It may even be the 16 addresses of the IS31FL3733 driver IC [Chris] Choosing this project is not enough, so he must be creative. Fearing that only using i2C multiplexers may cause capacitance problems, he chose to run 3 different i2C buses on the Raspberry Pi 4 to connect to all 48 controllers.
The second challenge is how to actually connect everything. The finished display is 26 inches wide and 20.5 inches high, which is too large for a single PCB. instead, [Chris] Choose to design a series of independent panels, each panel has 6 display modules and an IS31FL3733 to drive them. Although the multiplexing arrangement does leave room for more segments on each panel, he chose this arrangement because it provides a beautiful, clean, 4:3 aspect ratio for the final display.
The end result is a unique and beautiful work, which Chris named “one-to-many”. As he said, he uses it to show images and art related to the inevitability of automation, machines replacing humans, and other “similar good things”. There is a video after the break, but if you are interested in watching the exhibition in person, it will be on display at the VisArt Hall Gallery in Rockville, Maryland, from September 3 to October 17, 2021. More information [Chris’s] website.
this is not [Chris’s] For the first adventure of using a 7-segment display in such a unique way, please click here to read the predecessor of the project we introduced last year.