I was recently sent a Piksey Atto by it’s creators at BnBe club. The Atto is the Latest in their range of small Arduino IDE compatible micro-controllers. You can see the earlier Piksey Pico in my last post on the binary clock. The Atto is a real step down in size from the Pico measuring just 20 x 13mm. While there are other very small Arduino compatible micro-controllers they are often limited by choice of processor and / or connections. With the Atto the makers have opted to use the same processor as the Arduino Leonardo (ATmega32U4) this ensures good level of capability and importantly simple installation – no additional config or 3rd party drivers needed just select the Leonardo in the IDE.

To get as much IO as possible 3 sides are used for connections. The Atto has castellation holes making it flexible to use both on prototyping boards and PCBs.

To make access to the end connections a little simpler I made a small adapter board from bits I had to hand.

Communication with the Arduino IDE was as promised very straight forward and I had the usual blink example working without a problem – note, the Atto does not have an onboard LED so you have to connect to your own to see Blink working.

Next was to decide an application for the Atto. IOT applications are an obvious route given it’s size but I had recently seen Arduino Nano code for a mini Tetris game and so for a bit of fun thought this would show off the size of the Atto well and be a bit different. You can see the finished results below and the to the right.

I had to make a couple of changes to IO assignments in the s/w as the Leonardo uses different pins for I2C to the Nano, the only other job was ‘tuning’ the buttons. The Tetris game connects to the buttons via a single analog pin using dividing resistors to give a different analog reading for each key combination. I had not seen this before and although not strictly needed here is simple way to squeeze a bit more IO out when you are short. For more on this see the following link http://fritzing.org/projects/arduino-5-buttons-keypad .

All in all the Atto is useful addition to the range of Arduino compatible micro-controllers, for me using the Leonardo processor is great step up from the competition, taking away the need for extra 3rd party drivers. It’s size does mean a couple of compromises, no onboard power regulator (there is still an external 5V connection pin) and no LED but I am happy to take these given it’s small size.

Credit to Badfeed for the original Tetris code