Raspberry Pi Roundup - a sand simulator, a cat face detector and a way to speed up I2C

Sand Simulator

The Ruiz Brothers over at Adafruit have created a really lovely sand simulator using a Raspberry Pi Zero, an accelerometer, an RGB LED matrix display, some small items and 3D-printed parts. Philip Burgess wrote the code which “simulates physics by calculating collisions and terminal velocity”. The 3D-printed handles border the LED display and two buttons switch mode and reset the simulation. You can read a tutorial here which explains how to make your own and see a video of it in action below:


Cat Recognition

Amsterdam-based software engineer Arkaitz Garro has taken a Raspberry Pi Zero and a camera module and fixed it, using what looks like a Pi Hut Zero View, to a window. The window is located near to his back door. When the camera recognises his cat (and no-one else’s), it sends him a message via Slack to open the door to admit his cat, Bobit, to the house. The Pi uses MotionEyeOS to detect movement and then sends the image to Amazon Web Services’ Rekognition AI software to identify the specific cat.

I2C speed

Matt, over at Raspberry Pi Spy, has blogged about a way to improve the performance of the I2C bus on a Raspberry Pi. The bus, which is used for, among other things, sensor readings and outputting to OLED displays defaults to 100Kb/s but can be made to go as fast as 400Kb/s by changing a value in /boot/config.txt. This can improve performance for some applications. For the full details, head over to this page.