Frequency meter with some of quite good performance, capable of measuring frequencies from 1Hz to 10MHz (9,999,999 Hz) with a resolution of 1 Hz over the entire range. Ideal for function generators or as a standalone meter. It is cheap and easy to make, with parts that can be bought anywhere, and with a small size that allow it to be mounted in the panel on any device.
400W car power amplifier. Based on a push-pull converter with TL494 (KA7500) driver, 500W of power is enough for four TDA7294 integrated amplifiers. Three three-digit multimeters on front-panel shows actual battery voltage, temperature, and estimated output power.
The “not-ordinary bulb”, as title say, typical glass and metal bulb with electronic inside. Powered from miniature AC-DC converter – i have used that one from 230-5V USB chargers – it has enough power (about 500mA) for few RGB leds. Next is Attiny13 (SOIC8 package) based RGB driver, it not only can change colors, but has 3 modes and an automatic color and mode saving to eeprom memory – so after power up you always will see last seen mode and color.
Electronic business card / scroll display. 85 SMD 0805 led’s matrix display, Atmega88V uController, and couple of other smd parts. Dimensions are 24mm x 85mm, supplied from 3V small coin battery. It will work for long time, even on discharged battery (2V). After button is pressed, device is waking-up from power-down mode and start scrolling text equivalent to pressed button. 4 text’s are saved in eeprom memory, each one can be 127 character length (128 cell is used for holding special end-char).
Interactive mug coaster, thanks to analog temperature sensor LM35 and uC builded-in analog-digital converter, device can read temperature from standing on it glass. Device calculates temperature and smoothly light-up our drink with slowly changed RGB colours. When temperature is under 20*C then displayed colors are cold, and when temperature is above 28*C then colors are hot. When nothing stands on device (temperatures from 20*C to 28*C) then it automatically swich off. Fusebits are: 4,8Hz internal clock, not divided by 8. Supply voltage is stabilized by 1117 type stabilizer to 3.6V. The red LED requires lower voltage, and current on that…
3W RGB mood lamp, a “mylonit” lamp from ikea. Powered from TNY245 based AC-DC converter. Next is Attiny13 based RGB driver, it not only can change colors, but has 3 modes and an automatic color and mode saving to eeprom memory – so after power up you always will see last seen mode and color.