Testing Your PCB
Note: This guide mainly applies to PCBs with on-board components already installed, and not PCBs that come bare and need a Pro Micro-compatible controller added to it. However, once you solder the controller to the PCB and install all the diodes for those type of PCBs, you can use this guide.
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Why Test Your PCBBefore soldering switches to your PCB, it's a good idea to it to make sure that there aren't any issues with it. In case there is an issue with the PCB, you'd be able to request a replacement PCB more easily.
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Equipment You'll NeedTo test your PCB, you'll need something electrically conductive to connect the two switch pin pads of a key. Here's a few things you can use:
- Tweezers
- Bent Paperclip
- Wire
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Key Tester SoftwareNext, you'll need something that can show you what keys have been pressed on the keyboard. Here's a few recommendations:
- QMK Configurator - Test Keyboard (Online - works for any OS)
- VIA (Windows, macOS, Linux)
- Use the
KEY TESTER
tab - If your keyboard PCB has VIA support, then you can also test the keyboard matrix to check for keys that don't register, like
Fn
, in a normal key tester
- Use the
- Karabiner-Elements (macOS)
- Open up Event Viewer within Karabiner-Elements
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How to Test Key PostionsNow that you've got everything to need to test your PCB, it's time to begin. Here's the steps:
- Plug the PCB into the computer via USB cable
- For each key position, take whatever you're using to connect the switch pin pads and touch both of them at the same time
- A key press should be detected by the tester software, unless it's a special key (see note below)
- Test all of the key positions in this manner
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Special/Layer Keys can't be directly testedSome keys, like Fn
/layer keys, lighting controls, etc. are unable to be detected using a key tester. That's because a key tester can only detect keycodes that a keyboard sends to the computer, whereas for these special codes, they are handled internally by the keyboard firmware and aren't sent to the computer.
To test an Fn
/layer key, you'll need to use one hand to hold that key down with your tool, while connecting the switch pin pads together for another key that uses the Fn
/layer key. Then see if the key tester will detect a key press. For example, on some PCBs, holding down Fn
while pressing 1
will output F1
to a computer.
If your keyboard has VIA support, then you can also test these keys by opening up VIA, going to the KEY TESTER
tab and then selecting Test Matrix
. You will then see the special keys light up in the app when pressed.