Just wanted to report on completing a quick electronics prototyping project – making a very tiny ATTiny45-based simple USB dongle.
I used the blueprints from here: http://macetech.com/blog/?q=node/46
Printed the thing on the Roland Modela in the Media Lab shop, stuffed it with components obtained from DigiKey (links) there are only 5…, and programmed with a combination of the code from macetech and this instructables tutorial, and voilla – it works.
The advantage of the ATTiny45-20 (as opposed to the 45 not ’20’, e.g. ’10’) is that it works at 5V, which is what you get from USB, and also has an internal oscillator and PLL that can go over 20MHz (@ 4.5V-5.5V), which surpasses the USB’s requirements of 16MHz. The ATTinyX5-10 will not do, as it doesn’t go over 10MHz. So basically this chip is all you need to create a USB device, how awesome is that?
This is the image I used for cutting out the board (it is to-scale at 500 DPI, meaning you can use it to mill your own board). The red marking can be used for cutting out the board:
I needed to create a small, cheap USB-enabled circuit to serve as a key logger, and I’ve found some nice projects online that explain how to do this.
