The following construction has just two features ideal for basic testing and troubleshooting on audio devices. Here low-frequency generator of structure / trackers offers the following uses: In function generator allows the injection of low-frequency signals in the way of audio devices such as amplifiers.Contrast,in low-frequency trackers feature allows you to listen to any low-frequency [...]

This device is fully functional sound card for PC. The main advantage of using PCM2704 against PCM2702 is much easier construction. The circuit can be powered directly from USB port. Source: diy4fun

This is a very simple and easy to build programmer for Atmel microcontrollers from AVR family. The microcontrollers must support serial programming. This programmer is connected to a PC through the RS232 serial interface and can be used with the PonyProg or Avrdude software programmer. Source: diy4fun

Yet another darkroom timer using a PIC 16F84A. All the functions are in firmware: Lamp(s) light at start of timing and turn off when timer reaches zero. A set of leds were added between the minute and second leds which blink during timer operation. 7 segment displays include tails for digits 6 and 9. A [...]

The light level can be adjusted with two push-buttons “Up” and “Down”. Controller in this application is PIC16F84 that drives BUZ11 mosfet. Dimmer is tested with a light bulb 12V/4W and mosftet didn’t get even warm (which was expected since the datasheet says: 50V/30A). Source: Elektronika.ba (niho) Forum post: Digital light dimmer

This small circuit is very simple to make,with only few components caps, resistors and the heart of this circuit is Attiny84 microcontroller running at 20MHz. Source: 5volt

I needed a solution to remotely turn on a computer. There are many hardware devices you can buy, but I thought Wake on LAN (WOL) would be the ideal solution and give me a chance to experiment with Microchips ENC28J60 Ethernet controller chip. WOL is a computer networking standard that allows a shut-down computer to [...]

This project shows the temperature on a three digit 7-segment display, it measures the temperature from -9.5 to 99 degrees Celcius in 0.5 C steps, or from 0 to 210 degrees Fahrenheit in 1.0 degrees steps. Because of the LED display the temperature is also readable in the dark. The TCN75 from MicroChip is used [...]

This code is for a simple RGB LED controller for 8 LEDs using a PIC16F628. The PIC selects each LED then turns on/off the respective colors then goes to the next LED. Source: Semifluid

How to make a simple yet professional looking UV lightbox for PCB production. With a few items salvaged and picked up in a sales you can make an effective PCB exposure box for less than half the price of the cheapest commercial boxes. I have made four of these units (some double sided) yet still [...]

The RGB LED driver described on this page uses logic level ‘N’ channel MOSFETs which allow it to control LED arrays or lamps at up to 5 amps per channel without heatsinks. The driver uses exactly the same firmware as the small RGB LED driver so you can use the same code and sequences with [...]