This project is a clock that does not contain any buttons, alarms, or settings. DS232 IC calculated the time for the clock and an IR detector adjusts the LCD backlight depending on the hand distance from the clock. [via]
Building a Simple Clock with IR Light Detector - [Link]
The circuit is able to burn a firmware into the microcontroller and uses only a 74HC00 (or 74HC132) and a couple of transistors to operate; it connects to the PC via RS232 native port or USB to RS232 interface. The control program, written in VB6, is fully available, in executable or source code form (easy to modify for implementing other micros). The circuit printed board layout in PDF 1:1 format and the electric schematic are also downloadable from the site below:
Simple Atmel AVR ATtiny2313 programmer with 74HC00 - [Link]
This charger is an automatic one that will prevent battery from overcharging. The circuit consists of two main parts a voltage and current regulator and a voltage monitoring circuit with a cutoff relay. When the battery voltage is below 12.6V the it’s charging and when voltage goes to 13.8 then charging process is stopped. [via]
Automatic battery charger – [Link]
The Soundcard Oscilloscope receives its data from the Soundcard with 44.1kHz and 16 Bit resolution. The data source can be selected in the Windows mixer (Microphone, Line-In or Wave). The frequency range depends on the sound card, but 20-20000Hz should be possible with all modern cards.
Soundcard Oscilloscope – [Link]