Kwasi-ich

This is the playground for my Arduino, Raspberry Pi and Web projects.

• Ride the PWM 2019-11-15

  Driving NeoPixel LEDs (and compatibles) with 800kHz on 8MHz AVR microcontrollers is a challenge. Here I present an alternative approach to bit banging. By using the PWM hardware it is more versatile than previous solutions and can be used for other purposes as well.

• Twice the trouble for half the price 2018-12-09

  If something is sold with phrases like “like …” or “compatible to …” or “drop in replacement for …” and in the same time it is much cheaper, then you should think twice if it is worth the money. In some cases I had to learn it the hard way.

• Strong encryption for small payloads on Arduino 2018-03-05

  Most time, the wireless communication between embedded devices like the Arduino happens in plain text. While block ciphers like AES are too bulky in terms of speed, payload and object code size, stream ciphers like RC4 do not offer a high level of security through the lack of diffusion. In this post I will describe a new method to use a modified stream cipher that offers diffusion and also works with no overhead on small payloads, that are common in such devices.

• Silencing GreenBox 2017-12-22

  I bought a Gigabyte Brix Gaming computer, which is a pretty strong machine for its size. But it has a major drawback: it is incredibly loud. Thus I have 3D printed a case and replaced the two 40 mm fans with 120 mm ones that are quiet.

• Introduction to OpenMAX on the Raspberry Pi 2017-11-26

  As I want to dive deeper into the Raspberry Pi, I tapped into the hardware accelerated media capabilities. This is my journey into OpenMAX.