A need arose to use an Oscilloscope to debug some Arduino projects. I had disposed of my Tektronix Mainframe and plugins and needed something more transportable. I looked on ebay and saw some 2 channel boxed units for around $70. I then came across what is claimed to be the worlds smallest oscilloscope, at gabotronics.com called the XMEGA Xprotolab. The module is 1"x1.6" with a 0.96" square lcd display, has an two oscilloscope channels, onboard Arbitrary waveform generator(AWG) and 8 channel logic analyser. It is based on an ATMEGA32 chip. The display would be a strain on the eyes to say the least. The good news is that the module has a USB port allowing a (bigger) version of the display to be seen on a computer. There is a larger version 3.3 x 1.75" with a 2.4x2.4" display called the XMEGA Xminilab which had an awful orange LCD; still too small. Looking around the site I found the Xprotoplain which has no display and relies totally on the computer display. The good news was the cost ...$20! It has the capability of a Bluetooth interface so I paid the extra $2 for the BT connector and placed an order.It arrived in 3 days (despite the christmas holiday).
Small size PCB!
The drivers and PC display software were easily installed following the instructions at here.I connected a wire from the AWG to channel 1 input.