There are now a few Instructables on how to re-program your MakeyMakey, but so far there is a "best kept secret" which I only stumbled upon after hours of playing with drivers and such nonsense!
This method is incredibly simple, and you don't need to know anything about Arduino, IDE's, I/O ports or random Windows drivers!
First though, major thanks to the Instructables MakeyMakey build night organisers, and to fizzPOP: The Birmingham Makerspace for helping out our new rural 'space with cool hardware!
Now let's go!
Step 1: You Will Need...
You will need:
A version 1.2 Makey Makey
2 double ended crocodile clip leads (as provided in the MakeyMakey kit, handily enough!)
USB cable to connect the Makey Makey to your computer
(On your computer)
An internet connection that can reach www.makeymakey.com/remap
Chrome or Firefox (I'll be using Chrome for this example, but it should work in Firefox too.)
Step 2: Clarity
To try and avoid confusion between the keyboard, the Simulated keyboard of the MakeyMakey, and the picture of a keyboard on your screen, I have used the following formatting:
F5 - Press F5 on your computer keyboard
Click - the physically silver "button" on your MakeyMakey
A - the on-screen picture of a keyboard
Step 3: Open Your Browser
Navigate to www.makeymakey.com/remap in a new tab ("middle click" that link, then come back)
You will see an image as shown here. But you've already checked it's version 1.2, right?
Now, follow the instructions - it's pretty simple. However, there may be a few gotchas, so I'll walk you through just in case.
Step 4: Connect the Crocodile Clips As Shown
Clip the crocodile leads on to the board as shown in the picture. Once securely attached, plug it in to your USB port.
Once plugged in, if the clips are set correctly, all the LEDs on the MakeyMakey will come on solid and bright at the same time.
If they do the usual flashing check, you've not got (at least one of) the connections securely made, so unplug the USB and try again.
Step 5: Once Correct, the Screen Will Change to the Second Image
Once correct, the screen will change to the second image. It takes about 4 seconds on my PC.
Then the LEDs will start pulsing slowly on and off together.
Step 6: Remove the Clips, and the Screen Will Automatically Update
Remove the clips, the LEDs will go out, and the screen will automatically change. Again, it takes about 4 seconds.
Step 7: Remapping
This screen is what you will see next.
If you look carefully, you will see that the number 1 is yellow.
First you select the input you want to change by scrolling left and right using left_arrow and right_arrow, then you hit Click- currently 1 is selected.
To navigate, you need to hold the earth panel on the board and tap left and right. It's a bit tedious, but once you get the hang of it, it will only take a minute or two to tweak the settings. Also, the selection will scroll, so A will move to M if you scroll left again.
(If you try pressing the keys on your keyboard, it won't work, and you'll get the error shown in image 2 - it doesn't hurt, but it doesn't do anything either!)
Click, and the yellow focus will switch to the keyboard, as shown in the next step.
HINT: If it isn't detecting your presses of the arrows, make sure you are holding the earth (the long silver strip on the bottom edge of the board) at the same time you touch the arrows. If you still have problems, hook one of the crocodile clips to the earth and tap the arrows with that.
Step 8: Remapping 2
When you Clickby touching the pad on the MakeyMakey, the yellow selection goes green, and the corresponding key on the keyboard picture goes yellow, so you can keep track of which key you are re-mapping.
Here, I have already remapped all the first keys to the digits 0 through 9, and . (fullstop or decimal point)
Navigating to the letter A and pressing Click enters the letter A in the box where 1 used to be. Simple, eh?
You can remap all the keys as you see fit.
Step 9: Losing Focus
If you click off the browser window or tab away, you will see the screen go dark. Just click on it to make it wake back up.
If you leave it too long it will time out.
Step 10: If You Take Too Long...
If you take too long between inputs (about 60 seconds or so) it will time out. Don't worry too much, you can hit F5 on your keyboard (or otherwise reload the tab) to start again, just be aware that the settings you've not yet saved will have been lost.
You do get a warning message before it times out though, as shown. Just touch the MakeyMakey inputs to clear it - just tap right_arrow to keep it active.
Step 11: Saving
This bit is slightly counter-intuitive.
Once the keys are all set to what you want, you have to press down_arrow to move to Save. Left_arrow and right_arrow will select as it did before, and the Click button will execute the chosen command.
Hit Save and you will see a confirmation screen. As before Click will make the selection in yellow, so scroll left_arrow once, and Click YES to commit the save.
Step 12: All Done!
Once the write is finished, you will see this screen.
Unplug your newly-remapped MakeyMakey, and then plug it in again to test it. Pressing the inputs will now play what you changed it to. Excellent, eh?
I've tested 3 MakeyMakey's at the same time on my laptop, so you have plenty of room for experiment now!
In theory you can hang 127 USB devices off a single main port, so no more excuses! You'll run out of letters before you run out of inputs.
I suggest you make a note of which MakeyMakey is programmed to what - it makes life easier.
Hope you enjoyed this. If you really want to get more technical, you can follow this Instructable and use the Arduino IDE to program in things like SHIFT keys and CTRL, too!