Schrodinger's Pico Bluetooth Keyboard

I’m trying to get Bluetooth working on a Raspberry Pi PICO using MicroPython. I want to make a keyboard that you can pair with a computer and then use without further connection hassles. ChatGPT is being very encouraging and upbeat about the task, but I’m not sure whether it is possible or not. I think I’ll only know that it can be done once I’ve got it working….

Update: I’m pretty sure this is impossible. The aioble library for MicroPython doesn’t support bonding and, although ChatGPT came up with all kinds of fictional ways of making this work, none of them are any good in the real world. Oh well. You learn as much from your failures as you do your successes……

Blue Chord Keyboard now in Hackspace Magazine

If you use both left handed and right handed keyboards at the same time you can channel your inner Rick Wakeman….

Issue 68 of HackSpace magazine is now out. On page 70 you can find my article that tells you how to create a Bluetooth connected chord keyboard using a PICO-W. There are lots of other great articles too. Well worth a read.

Bluetooth Chord Keyboard

Now avaialble for left and right handed users with adjustable key positions

The Raspberry Pi PICO-W powered Bluetooth Chord keyboard (I call it “Blue Chords”) is now on GitHub. You can find it here. I’ve updated the code to use the latest version of the Raspberry PI PICO SDK and updated the PC design and matching case design.

I used the Kicadstepup plugin to import the board into the design

I’ve built some prototypes (you can see them at the top) but I’ve not built the final design yet. The project will be the basis of an article in an upcoming HackSpace magazine.

The First Rule of 3D Printing

I am typing this with the nearly finished “Blue Chords” keyboard. After a five hour print the key cover looks really nice. The keys and the sockets on the printed circuit board all line up perfectly and it seems to work. I now have to create the bottom of the case and fix the battery in place.

Oh, and the “First Rule of 3D Printing”? When your printer is printing well do not touch it or change anything.

The Bluetooth Chord Keyboard Lives

I want to use this keyboard with my left hand and move the mouse with my right…..

The last few days have been fun. I’ve been creating the software for the PICO Bluetooth Chord keyboard, otherwise known as “Blue-Chords”. I’ve been batting with CMake (which I’ve never previously had to tangle with much). It turns out to be a bit fiddly. I mentioned it to number one son and he was able to build a free-standing version of the example code which was terribly helpful.

Anyhoo, today I dropped the chord reading code into the software and I now have a working chord keyboard which can talk over Bluetooth. Next stop is to build the case….

Lovely OLED driver for the PICO

It can say other words as well…..

I spent a chunk of the day trying to get the OLED display working on the keyboard I’m building. It works fine under Python, but it was a bit reluctant to work under C++. In the end I found this lovely OLED library: https://github.com/daschr/pico-ssd1306 It's very lightweight and easy to configure and use. It worked a treat. The display that I’m using is the monochrome version and it looks really, really good.

Achievement unlocked: First PCB built

The bag was very hard to undo, but worth it

A parcel arrived from PCBWay today. These are the boards that I designed last week. They turned them round in double quick time and they look great.

These are the key positions for right handed use

I lost no time soldering the key sockets into place and getting a test program into the PICO. I have made a few mistakes with this board. The key spacing is a tiny bit close. I had to file a bit off a couple of keytops to make them move smoothly. The next version will have the keys a mm or so further apart.

It is traditional that your first board needs a fix or two….

I’d also made a mistake with one of the OLD display sockets, reversing the clock and data lines. But I managed to fix that and get the board going with some Python code. The good news is that the left handed versions is wired perfectly. I’m going to build one of those too just to see if it is easy to learn to use the keyboard with your left hand. Now I have to write the C++ code to read the keys and send the keypresses over Bluetooth.

Achievement unlocked: designed KiCad circuit board

I’m rather proud of this. Please don’t find a fault in it…

I’ve finished my design for the chord keyboard. There are lots of key locations but you only put one switch in each column. This makes it easy to make left or right handed versions. I’ve added connections for a tiny OLED screen. You fit the display the the side that you are not using.

Next thing to do is to send it off to get some boards made. Rather exciting.

Pico tamed

I’m making a bluetooth version of this….

Today all my fiddling with the PICO paid off. I got one of the Bluetooth examples for the PICO-W working and sending keys to my PC. Next step is to put it inside a wireless version of my chord keyboard.

Even famouser - Chord keyboard now on Hackaday

I drop in on Hackaday every now and then to see what folks are up to. I’ve just discovered that they have done a write up of the PICO Chord Keyboard which is rather nice. Thanks folks.

The PICO Chord Keyboard made the big time

Achievement unlocked. Number one son tells me that my Raspberry Pi PICO keyboard made the Raspberry Pi news feed last month.

If you’re wondering who Ben Everard is, he’s the editor of Hackspace magazine, which published the article about the keyboard. You can find it here.

Gotta love coloured wires

This is the wiring for my PICO chord keyboard. I made the artistic decision to use coloured wires, and I’m pleased that I did. Although I don’t think that the electricity cares that much.