This simple ATTiny 2313-based USB media controller design from Rupert Hirst lets you add an external volume and mute control to your PC. It uses V-USB, a software implementation of a USB 1.1 compliant for lower end AVR microcontrollers that do not natively support USB.
USB media control using ATTiny2313
I chose to go with the Zener 3V6 (3.6volts) diode approach to keep the Micro power rails at 5volts as I have in most of my experiments.The specification of the 3V6 type Zener is very important to the design, the total power consumption of the part must be no more than 500mw (0.5w)! due to extra capacitance on the USB -DATA and +DATA lines. A Zener rated at 250mw (0.25w) would be ideal yet I have yet to find any in a through hole part.
ThomasVDD‘s DIY capacitance meter uses a 555 timer circuit as a monostable multivibrator, where the output pulse interval depends upon the value of the capacitance to me measured. An ATTiny84 is used to measure the duration of the 555 timer output pulse, and thus compute the capacitance, which is then displayed on a seven segment LED display module.
A while ago I also posted a tutorial on how to measure capacitance with a PIC microcontroller.
Digital capacitance meter
This project, named IViny, is about an easy-to-build USB based data acquisition device using ATtiny85 MCU that communicates to a PC using V-USB. It is capable of logging data to the computer at 150 samples/sec. It features:
- 2 channels 0 – 5V and 0 – 3V digital input/output
- 2 channels 0 – 5V 10 bit analog input
- Channel maximum current 20 mA
- ATTiny85 based
- USB supply, no need external supply
- V-USB based communication
- PC user interface
- 150 Samples/sec
- 50 mm x 33 mm x 17 mm
IViny: A tiny datalogger device using ATtiny85