.-----___-----.
 RESET ---| O |--- VCC
PB3/ADC3/~OC1B ---| TINY85 |--- PB2/ADC1/SCL/T0
PB4/ADC2/OC1B ---| |--- PB1/OC0B/OC1A
 GND ---| |--- PB0/SDA/OC0A/~OC1A/AREF
 '-------------'

This is a collection of short Arduino sketches I have written for the ATtiny85 microcontroller.

• smartboost: software-configurable boost converter power supply
• clocksync: synchronize DC motor to mains frequency to run electric clock

• I prefer the Sparkfun Tiny AVR Programmer to program the ATtiny85s.

• The circuit diagrams, where included, have been rendered with Schemascii.

• Unless otherwise noted: for those sketches that use I2C communication, SDA and SCL are as indicated in the diagram above and require external pull-ups, and the protocol for communication is a standard register-based read-write method, done as follows:

  • To write a register or block of contiguous registers: write the first register's index, followed by register contents. Register pointer auto-increments, and wraps at the end. In Arduino code:

    Wire.beginTransmission(XXX);
    Wire.write(regAddress);
    Wire.write(myData, sizeof(myData));
    Wire.endTransmission();

  • To read a register or block of contiguous registers: write the first register's index, issue an I2C restart, and then read. Register pointer auto-increments, but does not wrap at the end. In Arduino code:

    Wire.beginTransmission(XXX);
    Wire.write(regAddress);
    Wire.endTransmission(false);
    Wire.requestFrom(XXX, NNN);

• The built-in I2C slave functionality is only present in Spence Konde's ATTinyCore, please use that when compiling these sketches.