Control a Macintosh Classic CRT with a BeagleBone Black – Part 3

Introduction

This is the final part of my series discussing my Macintosh Classic CRT project. In this article I want to give you a summary of my future ideas for the macdisplay project.

Continue reading Control a Macintosh Classic CRT with a BeagleBone Black – Part 3

Control a Macintosh Classic CRT with a BeagleBone Black – Intro

Almost one year ago I found an old Macintosh Classic, produced in the 1990’s in a basement. I bought it from the guy who used to own it and he told me, that he doesn’t know whether it is working or not and that it was standing there for about 20 years. Needless to say that it was in a pretty bad shape. After it arrived at my apartment, I immediately plugged it in and switched it on. Once the screen came on, it was pretty disappointing: It just displayed a checkerboard, which seems to be a pretty common issue with these models. This problem is caused by a variety of issues.

Continue reading Control a Macintosh Classic CRT with a BeagleBone Black – Intro

BeagleBone Black PRU clock cycle counter

Introduction

Today’s article will be a short one in which I’ll cover the so called cycle counter register (DWT_CYCCNT), which is present on the BBB’s PRU cores and on other CPUs from the Cortex architecture (See here). However this register is implementation dependent, so it might not be available on chips from some vendors. If this register is not present on a chip, it will always read zero. This register counts the number of cycles for which the PRU has been enabled. Continue reading BeagleBone Black PRU clock cycle counter

How to use hardware PWM/CLK to get exact timings on a Raspberry Pi

Introduction

This might not be a common issue, that hobbyists run into when creating their projects, because usually the software PWM, offered by the raspberry pi’s RPi.GPIO-Module, is exact enough for dimming some lights or controlling dc-motors. But for real-time and time-critical applications, this is actually an issue: Continue reading How to use hardware PWM/CLK to get exact timings on a Raspberry Pi