I2C the Hard Way

I2C the Hard Way

[Igor] has an AS5600 magnetic rotary encoder chip on a breakout board. Normally, you’d think that was an easy device to work with since it has an I2C interface. But [Igor] wanted to do it the hard way. What’s the hard way? By hand. He directly manipulates the clock and data lines using some push buttons. You can see how it goes in the video below.


This is possible because the controlling device — in this case [Igor] — gets to set the clock rate, and there’s no reason it has to be regular. We have to admit that it never occurred to us to do this, but we have written “bit banged” I2C-like code before.



The practical value of this isn’t clear, but we were still impressed. Certainly, if you had to write code or build hardware to operate the protocol, this would tell you quickly if you understood the fundamentals. We wonder if his next trick will be RS232 via Morse code key.


If you want a deep dive into the world of I2C, we can help with that. This reminded us of the old “paperclip computer book” that showed how to make your own computer with oatmeal boxes and paperclips. You just had to do the work of the CPU yourself.




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