Bread Heads - AVR Breadboard Programmers

I recently found myself needing to reuse some older prototypes for a newer project, as part of the repurposing I needed to flash an Arduino compatible bootloader on the AVR processors in them. The design didn't include an ICSP header so I wanted to find an easier way to flash…

CNC Auxiliary Input Board

After a little mishap involving my CNC machine I have been slowly restoring it to working order with a few pitfalls on the way. This post describes a small Arduino compatible auxiliary input board I designed around a ATmega8 microcontroller. Overview I recently replaced the main control board on my…

TGL-6502 Hardware Design

In this post I describe the hardware design of the TGL-6502 emulator board. The full schematic is available in the GitHub repository (PDF), it might be worth opening it in another window for reference while reading this post. I started this project as a challenge to see how much I…

Programming the TGL-6502

This post describes how to develop software for my TGL-6502 emulator board. The most recent update to the GitHub repository includes a desktop implementation of the emulator software so you don't need to build the hardware to write and test programs. Overview This is going to be a very long…

5 Simple Ways to Save IO Pins

It has been far too long since I have put up a new post so I thought I would share some techniques I've discovered while working with low pin count micro-controllers like the ATtiny85, LPC810 and the PIC16F1827. A lack of IO pins can be a limiting factor but there…

PWM Output on the ATtiny85

The next step in the Bluebell project is a way to provide notifications. We can control the device remotely using Bluetooth and now we need to make it display the data sent to it in an easily noticeable format. I'm going to use an RGB LED for this - it…

Using the HC-05 Bluetooth Breakout

In my previous post I described the implementation of a two pin, interrupt driven serial interface for the ATtiny - in this post I'll describe how to configure and use a HC-05 Bluetooth breakout board with that interface so you can remotely control any ATtiny based circuit. The HC-05 Bluetooth…

A Software UART for the ATtiny85

I've recently started work on a small project to provide visual notifications from a PC over a Bluetooth connection. I mentioned it on G+ a little while ago, it's essentially a minimalist version of this product. I started working on a post describing the work I was doing but it…