ATtiny85
From Leo's Notes
This page was last edited on 27 July 2021, at 06:41.
The ATTiny85 is an Atmel 8-bit AVR microcontroller. It's main features are its low power consumption and its small form factor.
The distinction between the other ATtiny microprocessors are:
| ATTiny25 | ATTiny45 | ATTiny85 | |
|---|---|---|---|
| Programmable Flash Memory (10k write/erase) | 2K | 4K | 8K |
| EEPROM (100k write/erase) | 128 bytes | 256 bytes | 512 bytes |
| SRAM | 128 bytes | 256 bytes | 512 bytes |
| Program Counter bits wide | 10 | 11 | 12 |
Random notes:
- All 6 port B pins can be used as IO lines to the internal 8 bit bus (high bits, lower 2 bits aren't connected?)
- System clock can be selected with CKSEL. It can use the internal 8MHz ocillator (with some options which sets it to 16 or 8mhz) An external clock is given with XTAL1 and XTAL2.
- Regardless of the oscillator, CLKPS sets the prescaler
- Setting the wrong clock setting can be problematic to recover from. You would likely need to inject a clock signal.
Fuses
- Settings are set with fuses. These fuses are actually flash/eeprom and used as configuration parameters.
- Fuse calculator at https://www.engbedded.com/fusecalc/
Flashing
Other resources
- https://www.electroschematics.com/attiny85-pwm-primer-tutorial-using-arduino/
- https://circuitdigest.com/microcontroller-projects/attiny85-ic-programming-through-usb-using-digispark-bootloader