Why is it you can never find the data sheet you need when you’re in a hurry?

I’m currently exploring (or as my More Significant Other puts it, ‘twotting about with’) AVR microcontrollers. This is a natural extension of my earlier addiction to Arduinos, which are the gateway drug of the microcontroller world. Sooner or later you start feeling constrained by the Arduino IDE and libraries. Yes, it’s lovely that your project actually works, but when that success is dependent entirely on libraries built by other people, where’s the achievement?

And so to the twotting…

My AVR chip of choice, for now, is the ATMEGA 328P. It’s what you find in an Arduino Uno and it’s a great all-purpose µproc. But I got tired of trying to remember which are the interrupt pins and which are the UART ones.

Yes, I have the data sheets on my computer, but I’m old-fashioned and when I’m working on the hardware I like to have the reference material nicely to hand. In other words, on paper.

So I created a couple of cheat sheets and I thought I’d share them. The one above simply shows the pinouts. You can click on it to see/save a larger version. As the ATMEGA 88 and ATMEGA 168 are pin-compatible with the 328, these diagrams work for those too.

Below is my worksheet version. This has the pinouts as an aide memoire and another version with blank spaces where I write what each pin is connected to.

And here’s a PDF version with lots of space around the diagrams for you to write notes, hastily scrawled circuit diagrams and shopping lists.

Let me know if you find them useful.