I grabbed an 8-conductor wire bundle and took a length that could reach from the IO expander to the far side of the keyboard, plus some extra for wire bending allowances. When I knew approximately where it would lie, I put some protective shrink tube around the bundle and fed it through one of the holes I drilled through the aluminum support. I trimmed the wires closest to the center, then stripped and tinned each column. I applied a shrink tube segment to each joint to isolate it from the frame.
I repeated the process on the other side, which had seven columns, where I repeated the wire order according to color. I trimmed the fifteen wires and terminated them on the IO expander. I connected the five rows with another bundle of wires through the central support, then ran more conductors to the microcontroller's digital IO pins.
In retrospect, I should have used an IO expander on the first side to avoid running eight wires. When I connected the microcontroller and LED cluster, I saw they did not rely on the same voltage, so I may have to add a booster and level shifter.
Switch matrix wired to IO expander
The rest of the posts for this project have been arranged by date.
First time here?
Completed projects from year 1
Completed projects from year 2
Completed projects from year 3
Completed projects from year 4
Completed projects from year 5
Completed projects from year 6
Completed projects from year 7
Completed projects from year 8
Disclaimer for http://24hourengineer.blogspot.com and 24HourEngineer.com
This disclaimer must be intact and whole. This disclaimer must be included if a project is distributed.
All information on this blog, or linked by this blog, is not to be taken as advice or solicitation. Anyone attempting to replicate, in whole or in part, is responsible for the outcome and procedure. Any loss of functionality, money, property, or similar, is the responsibility of those involved in the replication.
All digital communication regarding the email address 24hourengineer@gmail.com becomes the intellectual property of Brian McEvoy. Any information contained within these messages may be distributed or retained at the discretion of Brian McEvoy. Any email sent to this address, or any email account owned by Brian McEvoy, cannot be used to claim property or assets.
Comments to the blog may be utilized or erased at the discretion of the owner. No one posting may claim property or assets based on their post.
This blog, including pictures and text, is copyright to Brian McEvoy.
2023-06-05
I repeated the process on the other side, which had seven columns, where I repeated the wire order according to color. I trimmed the fifteen wires and terminated them on the IO expander. I connected the five rows with another bundle of wires through the central support, then ran more conductors to the microcontroller's digital IO pins.
In retrospect, I should have used an IO expander on the first side to avoid running eight wires. When I connected the microcontroller and LED cluster, I saw they did not rely on the same voltage, so I may have to add a booster and level shifter.
The rest of the posts for this project have been arranged by date.
First time here?
Completed projects from year 1
Completed projects from year 2
Completed projects from year 3
Completed projects from year 4
Completed projects from year 5
Completed projects from year 6
Completed projects from year 7
Completed projects from year 8
Disclaimer for http://24hourengineer.blogspot.com and 24HourEngineer.com
This disclaimer must be intact and whole. This disclaimer must be included if a project is distributed.
All information on this blog, or linked by this blog, is not to be taken as advice or solicitation. Anyone attempting to replicate, in whole or in part, is responsible for the outcome and procedure. Any loss of functionality, money, property, or similar, is the responsibility of those involved in the replication.
All digital communication regarding the email address 24hourengineer@gmail.com becomes the intellectual property of Brian McEvoy. Any information contained within these messages may be distributed or retained at the discretion of Brian McEvoy. Any email sent to this address, or any email account owned by Brian McEvoy, cannot be used to claim property or assets.
Comments to the blog may be utilized or erased at the discretion of the owner. No one posting may claim property or assets based on their post.
This blog, including pictures and text, is copyright to Brian McEvoy.
2023-06-05
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