Circuit Lake

Electronic Project and Circuit Collection

AVR LED Candle

02/29/2012 Category: AVR, LED, Miscellaneous, Project

This LED candle is built to mimic the look of a traditional candle without the dangers associated with an open flame. It uses high brightness LED and is controlled by ATtiny85. It could be useful as movie props where you cannot afford to have a candle go out during a take or in your home in places not suitable for traditional candles such as in a wall niche or alcove.

LED candle DIY project

Pete made this candle with a Light Detecting Resistor ( LDR ) and a fixed resistor acting as a voltage divider. This is fed to one of the ATtiny85’s ADC inputs and sampled at discrete time intervals. At this time, the sample rate is 100mS. These 8-bit light level values are then stored to EEPROM so that the candle can recall the flicker pattern to play back on the LED that is connected to a PWM channel after being turned off. You only need to program the pattern once, but you can program it over and over again with just the push of a button.

LED Candle
Project Firmware, Schematic and Documentation