Recently I discovered that the Teensy 2.0 can be bought on Aliexpress for $7.50 or less. It’s not as cheap as Pro Micro ‘Big chip’ you can get for $3.60 but a good alternative if want to make an fully compatible Arduboy clone and you’re not good at soldering tiny wires. The Teensy 2.0 has all the I/O pins broken out that are used by Arduboy.
There are no Power, Rx and Tx LEDs. This is good for making a low power Arduboy. But if you want the Rx and Tx LEDs you can add them as the required pins are broken out.
The Teensy 2.0 uses a mini USB connector instead of micro USB. It comes with a short mini USB cable though.
The Teensy 2.0 uses a non CDC class Bootloader. So you’ll need to reflash the bootloader using another Arduino or an ISP programmer like an USBasp.
Here’s a picture of how things should be wired:
If you’re planning on using a lipo battery for power, here’s how you can wire a TP4056 charging module:
