b61baf4281
With my XD60, I noticed that when typing the backlight was flickering. The XD60 doesn't have the backlight wired to a hardware PWM pin. I assumed it was a timing issue in the matrix scan that made the PWM lit the LED a bit too longer. I verified it because the more keys that were pressed, the more lighting I observed. This patch makes the software PWM be called during CPU interruptions. It works almost like the hardware PWM, except instead of using the CPU waveform generation, the CPU will fire interruption when the LEDs need be turned on or off. Using the same timer system as for hardware PWM, when the counter will reach OCRxx (the current backlight level), an Output Compare match interrupt will be fired and we'll turn the LEDs off. When the counter reaches its maximum value, an overflow interrupt will be triggered in which we turn the LEDs on. This way we replicate the hardware backlight PWM duty cycle. This gives a better time stability of the PWM computation than pure software PWM, leading to a flicker free backlight. Since this is reusing the hardware PWM code, software PWM also supports backlight breathing. Note that if timer1 is used for audio, backlight will use timer3, and if timer3 is used for audio backlight will use timer1. If both timers are used for audio, then this feature is disabled and we revert to the matrix scan based PWM computation. Signed-off-by: Brice Figureau <brice@daysofwonder.com>
Quantum Mechanical Keyboard Firmware
What is QMK Firmware?
QMK (Quantum Mechanical Keyboard) is an open source community that maintains QMK Firmware, QMK Toolbox, qmk.fm, and these docs. QMK Firmware is a keyboard firmware based on the tmk_keyboard with some useful features for Atmel AVR controllers, and more specifically, the OLKB product line, the ErgoDox EZ keyboard, and the Clueboard product line. It has also been ported to ARM chips using ChibiOS. You can use it to power your own hand-wired or custom keyboard PCB.
How to Get It
If you plan on contributing a keymap, keyboard, or features to QMK, the easiest thing to do is fork the repo through Github, and clone your repo locally to make your changes, push them, then open a Pull Request from your fork.
Otherwise, you can either download it directly (zip, tar), or clone it via git (git@github.com:qmk/qmk_firmware.git), or https (https://github.com/qmk/qmk_firmware.git).
How to Compile
Before you are able to compile, you'll need to install an environment for AVR or/and ARM development. Once that is complete, you'll use the make command to build a keyboard and keymap with the following notation:
make planck/rev4:default
This would build the rev4 revision of the planck with the default keymap. Not all keyboards have revisions (also called subprojects or folders), in which case, it can be omitted:
make preonic:default
How to Customize
QMK has lots of features to explore, and a good deal of reference documentation to dig through. Most features are taken advantage of by modifying your keymap, and changing the keycodes.