This is a firmware for ATTiny85 microcontrollers providing a PWM signal controlled via I²C. The microcontroller acts as a I²C slave and allows a single byte write operation which is used unmodified as PWM output value.
Beside the usual VCC andGND pins, the following pins are used:
- 5 (
PB0) - I²C SDA - 6 (
PB1) - PWM output - 7 (
PB2) - I²C SCL
The I²C pins utilize the internal pull-ups but external pull-up resistors should be added according to the specifications.
The configuration can be done by mondifying config.h accordin to the needs.
Right now, there are only two options to set:
TWI_ADDRESS- Contains the address of the slave on the I²C bus. This must only contain the leading 7 bit of the address without the R/W flag.PWM_PRESCALER- The prescaler to use for the PWM output. See Table 12-5 in the ATTiny85 datasheed vor valid values. All settings are relative to 8MHz CPU frequence.