I'm a big fan of early ATtiny series chips, I even made my own ATtiny Flasher tool for productive development and few educational kites based on ubiquitous ATtiny85. Time has come to extend my horizons and look into the modern line of ATtiny chips, specifically so called 1-series and 2-series line of MCUs. No need to mention that they went far ahead old series, and having resources comparable with old ATmega series.
This gave me an idea to make Arduino Nano pin compatible development board, so I can start using it the projects, where I'd normally pick Arduino Nano. In my practice the best way to get familiar with new hardware is to start using it in the actual projects.
So here it is, Arduino Nano replacement, but with modern ATtiny MCU onboard.
If you want to start working on modern ATtiny series chips, you need two fundamental materials contributed by Spence Konde. First being the flashing instructions (much more than that actually) and second Arduino core description. Both will give you more than enough to get started and litle extra knowledge to fit your expectation to the reality around these chips.
- (a) Legacy way is to take any Arduino Nano board and use jtag2updi project to make yourself programmer.
- (b) Better (read recommended) way is to use SerialUPDI tooling with hardware modified serial programmer
- (c) Alternative is to use Optiboot bootloader and Serial programmer interface like on Arduino boards
Method (c) is disqualified on 1-Series chip because of RESET/UPDI pin collision, and both (a) and (b) work equally well, difference being what is easier for you: (a) dedicate Arduino Nano board for programming or (b) do solder job on your usb-serial adapter.
Having this said, you ready to write your own code. Changing pin states is rather lacking drama, using built-in libraries like SPI or I2C also seems simple.
I guess this is the same for every new product, same situation for RP2040 after it went live, community support came later. Not sure if modern Tiny series will gain same momentum eventually, probably not.