RE: Blog #5 I2C Attiny 85 Communication

misaz — Mon, 26 Jun 2023 21:42:55 GMT

Congrats. For saving time buy logic analyzer.There are some expensive one, but since I2C is very slow cheepest chinese are also suitable. The most cost efective way is Aliexpress (around 9 USD nowadays): https://www.aliexpress.com/item/1005003375736481.html. I bought it for 13 USD several years ago and it saved be thousands of hours of debugging (not only low level codes).

It will show you what is happending on the I2C bus (and other signals). Mentioned samples at 24 MHz and is suitable for analysing buses up to 12 MHz which 0.4MHz I2C fully satisfy.

If you cant find working library there is no better way than write your own. While you was trying several third-party software which did not work right for you, it was possibly more cost efective learn how do the I2C and ATtiny86 work and write your own software from scratch. ATtiny86 is old microcontroller and have no I2C peripheral. There is USI which can be used for implementing partialy hardware accelerated I2C slave. Library you find most probably control it in tricky way or implement I2C slave using bitband method (directly reading GPIOs and driving them). The second mentioned is simple to implement yourself.