Even with the V3 boards not being perfect for the buttons, I still managed to make them work. The two jumper wires on the Arduino Rp2040 is for a special function of the io expander. I am not sure I want to use the feature, but still want to test it. Each wired pin connects to an output on the io expander, which should output a block of pin states as an interrupt for the Arduino.
Testing and coding will commence this week. I remember when this project was about a wrist mounted Cyberdeck (pipboy) with the raspberry pi z2, but I guess it's turning into an HMI problem. Wearables seem to always need a way to make the interactions more intuitive or have high enough functionality that they aren't a pain to use. A device thats tedious to use, stops getting used.
Writing this out more for myself than anyone else.
After testing my version 3 boards, It seems that I lengthened the wrong footprint pins of the 6mm buttons. Although the buttons fit, they only fit in the wrong orientation. Lessons learned: never trust a 3rd party library, measure twice, don't fix your board designs at 1am.
Below are some photos of the beautiful, but wrong v3 boards.
Time to wait for the new boards, again 😅
I suppose I'll move on for now to design the main housing for the raspberry pi and display.
Don't you just love 3d printers. Whatever shape you need, you can have, lol. Anyways the mount for the PCBs is in progress, I think they'll be another revision to it, once I have all the components in hand and can test the hand fit. Otherwise I am happy with it. I am debating now whether to make the shell of this keyboard extremely ergonomic or have it barebones cyberpunk, ergolite. The pcb production is also coming along, so that's nice.
In the previous post, I mentioned that I was considering using an io expander and I did! I am using the MCP23017E/SO, which will read in all keys. The thumb navigation switch will be connected directly to the Arduino Rp2040. Here is the OSHPark Board OSH Park ~
And now I'll turn back to the ME and ID work until I receive the PCB's!
And the Keyboard segments can be found here on OSH Park ~
After giving it some thought, I'll probably add on this GPIO expander. I might only attach the keyboard segments to it though. I'd like to retain my i2c lines for also using the IMU and other sensors that come with the Arduino Connect RP2040, which would be impossible if I used all of it's gpio for buttons.
After my previous build of a chorded keyboard using Cherry MX Switches, it was clear that I needed to work with smaller components if I was going to have any more keys. Not wanting to solder to the pins of smaller switches and deal with designing complex mounting to make them secure, I decided to design a pcb segment for 4 switches.
I am planning on using an Arduino Connect as the main micro to run the chorded keyboard, and it has enough GPIO for me to be satisfied wiring the switches independently, with a shared ground plane.