Home
JAQForum Ver 20.06
Log In or Join  
Active Topics
Local Time 20:03 18 May 2024 Privacy Policy
Jump to

Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me.

Forum Index : Microcontroller and PC projects : 8x8 Matrix Transcoder.

Author Message
Grogster

Admin Group

Joined: 31/12/2012
Location: New Zealand
Posts: 9082
Posted: 03:36am 01 Jul 2015
Copy link to clipboard 
Print this post

Hi folks.

After playing about with various matrix encoders, and various methods of decoding larger matrices with the MM, I decided to just dedicate a MM chip to the task - they are so cheap, and this will allow a MM to concentrate solely on the matrix, meaning that the main MM does not have to deal with the workload of scanning a larger matrix in combination with keeping up with the main code.

TOP LAYER:




BOTTOM LAYER:




BOTH LAYERS:




The PCB is 50mm square, and uses all through-hole construction for easy assembly.

The Micromite chip is dedicated to scanning the matrix looking for keypresses, and then transcoding those keypresses on the matrix, to standard serial ASCII that is squirted out on COM1 at 9600 baud. You can change the baud-rate in the code to whatever you want. The idea behind using the serial port, is that with a matching MM chip setup as a serial-port with interrupt, the code running on the other MM can interrupt as soon as this board sends any serial data, which makes it really easy to process. Even if you don't use the serial interrupt idea, the built-in serial port buffer will automatically store any received data in the background, and you can process it later if you want.

This is NOT a new idea, and only of use if you need more then the 4x4 matrix already supported by the MM's KEYPAD command. This PCB can be setup for any matrix size you want up to 8x8.

It was designed for keypad matrices, but you could use any situation where you needed to interface many contact closures such as in a relay matrix.

I will be getting some of these boards made, so if anyone is interested, post a comment here on this thread.

EDIT: Opps - slight mistake there - console pins are wrong - will fix that.
EDIT: Fixed images to include console and 1k on console RXD for 5v protection. Edited by Grogster 2015-07-02
Smoke makes things work. When the smoke gets out, it stops!
 
Print this page


To reply to this topic, you need to log in.

© JAQ Software 2024