All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.
Generally, all APIs that synchronously provide layout metrics will trigger forced reflow / layout. Read on for additional cases and details.
elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent
Update on Nov 30, 2025: This Gist is nearly eight years old! These instructions worked back in 2018 for the Pi 3, but recent comments suggest that they may not be sufficient on more recent Pi models and newer versions of Raspberry Pi OS. Be advised.
On my RetroPie machine I wanted a hardware volume knob — the games I play use a handful of emulators, and there's no unified software interface for controlling the volume. The speakers I got for my cabinet are great, but don't have their own hardware volume knob. So with a bunch of googling and trial and error, I figured out what I need to pull this off: a rotary encoder and a daemon that listens for the signals it sends.
| //#define CALIBRATE | |
| //#define GRID // After Calibration this mode should plot a pretty good dot grid on the screen | |
| // See additional calibration comments in the code down by the "#ifdef CALIBRATE" | |
| // Adjust these values for servo arms in position for state 1 _| | |
| const double SERVO_LEFT_ZERO = 1600; | |
| const double SERVO_RIGHT_SCALE = 690; // + makes rotate further left | |
| // Adjust these values for servo arms in position for state 2 |_ | |
| const double SERVO_RIGHT_ZERO = 650; |
Since documentation has been somewhat lacking... here is a quick write-up to get started!
Sources:
Boards:
| These commands are based on a askubuntu answer http://askubuntu.com/a/581497 | |
| To install gcc-6 (gcc-6.1.1), I had to do more stuff as shown below. | |
| USE THOSE COMMANDS AT YOUR OWN RISK. I SHALL NOT BE RESPONSIBLE FOR ANYTHING. | |
| ABSOLUTELY NO WARRANTY. | |
| If you are still reading let's carry on with the code. | |
| sudo apt-get update && \ | |
| sudo apt-get install build-essential software-properties-common -y && \ | |
| sudo add-apt-repository ppa:ubuntu-toolchain-r/test -y && \ |
| - type: custom:apexcharts-card | |
| graph_span: 1d | |
| header: | |
| show: true | |
| title: Electriciteitsprijzen Vandaag (€/kwh) | |
| span: | |
| start: day | |
| now: | |
| show: true | |
| label: Now |
| # Scanner i2c en MicroPython | MicroPython i2c scanner | |
| # Renvoi l'adresse en decimal et hexa de chaque device connecte sur le bus i2c | |
| # Return decimal and hexa adress of each i2c device | |
| # https://projetsdiy.fr - https://diyprojects.io (dec. 2017) | |
| import machine | |
| i2c = machine.I2C(scl=machine.Pin(5), sda=machine.Pin(4)) | |
| print('Scan i2c bus...') | |
| devices = i2c.scan() |
| ### WARNING: READ CAREFULLY BEFORE ATTEMPTING ### | |
| # | |
| # Officially, this is not recommended. YMMV | |
| # https://www.raspberrypi.com/news/bookworm-the-new-version-of-raspberry-pi-os/ | |
| # | |
| # This mostly works if you are on 64bit. You are on your own if you are on 32bit or mixed 64/32bit | |
| # | |
| # Credit to anfractuosity and fgimenezm for figuring out additional details for kernels | |
| # |
I use multiple devices to control my 3D printer and it's alwys a hassle to move changes on profiles etc. between those machines leading to situations where I use an old version of my profiles to print a part because I just forgot to update it.
Here is how you can sync Cura settings between multiple devices:
cura to any convinient location inside your Google Drive / OneDrive / Dropbox folder. You can also rename the folder form cura to somthing else, I called mine Cura Settings.%userprofile%\AppData\Roaming\cura