⚠️ It is important to cut the VBUS line ⚠️Īn important thing to do before soldering the 2 boards together is to cut the VBUS line on the USB Host Shield.
Pro Micro soldered onto USB Host Shield (Source: ) These are the guides I followed to solder the Pro Micro to the Mini USB Host Shield: NKRO is still unfamiliar for me and as of now, it seems like the the HID report descriptor is used to enable NKRO. Reading more on building hand-wired keyboards will allow you to understand more of how the keyboard matrix is done. The reason behind this is that a microcontroller only has a limited number of inputs which does not match the 70++ keys that a keyboard might have. The general idea is to use a diode (like 1N148) which allows for the flow of current in one direction.
Here are a few good examples explaining how does ghosting happen and how to prevent it (using diodes). To get to NKRO, we need to first prevent ghosting which can occur in the keyboard’s matrix. 4 pairs of modifiers (Shift, Control, Alt and Windows/Command).
The HID USB boot protocol operates in 6KRO which imposes a limit of six concurrent keys plus modifiers:
BIOS, bootloaders and KVM switches), the USB HID standard specifies that keyboards and mice can declare themselves to be “boot-capable” (source). To avoid complexity in simpler USB stacks (e.g. Here are some information regarding the different operating modes of a typical/gaming keyboard.
geekhack - Review: hasu’s TMK USB to USB Converterĭigging further, I found out that there is a way to DIY the converter with just:.geekhack - USB to USB keyboard converter.Here are some reviews on Hasu’s implementation: Well, turns out there is already such implementation out there (Hasu’s USB to USB converter), but it is too expensive for me. To reprogram a “dumb” keyboard we need to connect it to a converter, where the converter is loaded with QMK Firmware. Unfortunately, most off-the-shelf keyboards do not come with a programmable firmware (like my keyboard). So QMK allows me to program a keyboard by adding custom functionality (keymaps and macros, etc), and that is good news. When you build your custom keymap, you are creating an executable program for your keyboard. QMK Firmware fills the role of that software, detecting button presses and passing that information on to the host computer.
This processor runs software that is responsible for detecting button presses and informing the computer when keys are pressed. Your computer keyboard has a processor inside of it, similar to the one inside your computer. We checked the fast-charging capabilities of each adaptor using a Samsung S10e smartphone, with a 3100mAh battery starting at around 50 per cent charge.The main motivation to build this converter came from this video by Linus Tech Tips where I found out that I can convert almost any USB keyboard into a fully programmable keyboard using QMK firmware.Īfter spending some time on /r/mechanicalkeyboards and /r/olkb I found out that custom mechanical keyboards are typically programmable via QMK firmware. It’s often good to have a choice of USB and USB-C to cover all bases. Having twin sockets comes in handy if you regularly charge two products, but make sure you buy an adaptor with outlets to suit your requirements. Between 7.5W and 10W is typical, but many more recent devices can be charged at a higher wattage, which is where USB-C comes into its own and why many adaptors have an increased rating. You should check the phone’s wattage capabilities.
Depending on your device, you may need an adaptor plug and cable, which should be added to the cost unless they’re supplied. Most chargers boost the standard 5V CLA output to 9V, using the original USB sockets or the latest symmetrical USB-C connection. And of course, it can also be used to charge a tablet, sat-nav, MP3 player, handheld game console or other devices. Many of the latest smartphones have fast-charge capability, but you’ll need a suitable USB adaptor to take advantage of this great feature in-car.
Charging your phone while you drive is sensible, especially if you use it for work.