i2c to SPI converter with Attiny 13?

Hey everyone,

in my current project I have only 2 wires left to be used for an Oled display. So i2c is the way. I killed my last SH1106 Oled while installing it and I ordered a new one. This time I went for a SDD1306 1,54 inch Oled only to find it just offers SPI and can´t be used in i2c mode.

While I was trying to google for a i2c to SPI bridge device I remembered that I have a couple of ATTiny13. Had them for years and never used them.

Is there a way to have an ATTiny13 recieve the i2c and translate it to SPI?

I have found this https://github.com/bunnie/i2c-spi-bridge

which uses an ATTiny85. If this could also work with a 13 could someone tell me how to connect it? I have never worked with it and can´t make heads or tails from the example code.

Alternatively: could I employ an Arduino Nano to do the conversion?

Cheers Chris

P.S.: I don´t need a super fast interface. The Oled will be used as a time and date display build into a wooden frame

The ATtiny13 has no I2C bus. The ATtiny85 has flexible universal hardware that does it all, it is called the USI (Universal Serial Interface). That makes a big difference.

You can use the ATtiny13 for a single task, or maybe two or three very simple tasks. Driving a fan with a pwm signal, reading an analog sensor, and so on.

The Arduino Nano can be a I2C Slave. You have to careful with that. Most examples for a Slave sketch are wrong.

Those displays are cheap. Get an i2c one, or research and find the jumper to move to put it into i2c mode (pretty sure the difference is just a jumper (0 Ohm resistor) to set the interface mode)

DrAzzy: Those displays are cheap. Get an i2c one, or research and find the jumper to move to put it into i2c mode (pretty sure the difference is just a jumper (0 Ohm resistor) to set the interface mode)

That one doesn´t seem to have it. It has resistors on the back, but not the usual you would expect for the interface selection.

The Arduino micro (not a nano, my bad) as a converter would be nice though. Any hints? Right now I could connect the display with SPI to the micro and have it receive data over serial and display it. But that wouldn´t allow me for OTA updates. Since it will be hidden behind some furniture is would be sweet to retain the OTA ability. Thats why I would love to have it run as a converter only.