ATtiny85 8MHz and ADXL345 via I2C with Arduino code

This is a small setup based on the ATtiny85 to make use of the advanced features of the ADXL345 accelerometer.

Parts

• Adafruit Trinket 3V ATtiny85 board
  • No need for level shifting for ADXL345 I2C
  • Comes with [Trinket Bootloader] to upload binary with USB during the first 10 seconds of power-up/reset
  • Red LED on #1/PB1 is handy for debugging
• GY-291 ADXL345 Digital 3-Axis accelerometer breakout
  • On-board 3.3V LDO for ADXL345
  • I2C 4.7k pull-ups
  • CS 4.7k pull-up - enable I2C, not SPI
  • SDO 4.7k pull-down - I2C address 0x53
  • Comes with 2.54mm pin header

Wiring

• ATtiny -> ADXL345
• USB -> VCC
• GND -> GND
• #0/PB0 -> SDA
• #2/PB2 -> SCL

Code

Code