Original project by: Владислав Шаповалов
Such multi-purpose device is a nice example of of using microcontroller for combined tasks. The idea of radio-clock-thermometer came up when authors car audio head-end was stolen. He decided to use what’s left left from car radio and build something nice. So the project has started.

Once I’ve got several HQM1286404 graphical LCD displays around so I decided to build a prototyping board where I could easily plug LCD to it, read data via ADC and display graphs, plug keypad if needed for some menu functions. Earlier I was testing graphical LCD on prototype breadboard, but dealing with multiple wires (GLCD [...]

Introduction
TDA7313 audio processor have been used for more than ten years in the industry because of its simplicity, functionality and good parameters like low distortion, low noise. Chip is based on BIPOLAR/CMOS technology and can be used in various applications including car radios, Hi-FI, simple mixers.
TDA7313 chip has 3 external stereo inputs, that allows to [...]

So this time I decided to make pretty simple but powerful enough audio amplifier. For this I’ve chosen quad bridge car audio amplifier TDA7384 which has four input and four output channels with power capability 4×35W(4Ω).

 
If connect to car battery where operating voltage is about 13.2V, then each channel can give 22W(4Ω) – what is [...]

USBASP is well known USB programmer for Atmel AVR microcontrollers originally supported by Thomas Fischl. USB ASP is made of an Atmega8 and few components. The programmer uses a firmware driver that makes this programmer attractive to many amateurs.
Another thin why this programmer is so popular – because it is officially included and supported [...]

Building AVR Jtag clone
Finally I found some time to finish AVRJTAG clone. It was hanging for a while on a breadboard with bunch of wires. I have made an Eagle CAD project with PCB layout you will find at the bottom of article.

 
I didn’t change the circuit very much from previous, just added ISP header(but [...]

After unsuccessful attempts to run few programs who drive peripherals like USART and Timers on Atmega128 I decided to make JTAG debugger. I hope it will allow me to see what is really happening – is may atmega128 corrupted or something is really wrong with software or with hardware.

 
The most widely used AVR JTAGICE clone [...]

Earlier I have written about Piconomic learning course and its nice development board they provide. You can purchase the board if you are from a South Africa internationally for $49.99 + $9.37 airmail shipping with a tracking number, which takes 2-4 weeks, depending on custom delays. Of course there is good opportunity to build this [...]

During spare time I made quick design of TTL to RS232 adapter, that works with my AVR development board. This adapter helps to connect TTL (Transistor-Transistor Logic) level signals to RS232 interface. TTL side is 9-pin female connector and RS232 sire is male connector.
Unit is powered from target board using power pins.
The RS232 TTL adapter [...]

Sometimes when tuning various electronic hardware we need simple signal generator with various waveform and frequency. One of the options is to by a professional with variable gain professional coating and many additional functions. But if you are an amateur you might want to build one. This small project is dedicated for building one of [...]