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Day2'ish - Design Electrical

A project log for Number Matrix V2

Version 2.0 of my number matrix. Will be 4 times the size and have grayscale.

seasleyeceseasleyece 01/30/2023 at 20:210 Comments

The display controller is based on the version that I used in my V1 matrix.  Biggest difference is that I dropped the RF module that I will never get around to doing anything with and increased the HUB75 drives from 2 chains to 4 chains.  Image of the layout is below.

The display boards are 4x the size of the V1 matrix holding a total of 32 quad even segment displays. Each Display board has a HUB75'ish display input.  The biggest difference is that there are two sets of 4-bit outputs rather then the HUB75 two 3-bit outputs.  The bits are shifted between the input and output connector.  i.e. input bit 1 goes to output bit 0 and so one.  This allows for all 4 panels in each chain to be updated at the same time.  This greatly reduces the clock speed needed to get the panels updated.  The segments are being drive at a 1/16th duty cycle.  This means that only 1/16 of the digits are one at any one time.  This is common with HUB75 based displays. An image of the Display board PWB is below.  For size comparison the actual board will be 8" by 7.8" or 202.69 mm* 157.12 mm in units that the rest of the world uses.

Here is a pretty rendering of the module done in OnShape.

Putting all 16 modules in we get a display that is 32"x24.7" with 32k+ pixels.

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