Sometimes, it’s better to DIY your own electronics project than buy it in the electronic shops. Honestly, you cannot even find some of the incredible devices elsewhere, unless you build it yourself!
In this case, this cheapest dual trace scope would be the best example. Different from the other dual trace scope, it’s a submini USB scope that based on an Atmel Tiny45 CPU.
Basically, it has two analog inputs and can supply 5V onto the 4 pins header on the right. For your information, one of the inputs can be easily scaled down with the trim pot.
Furthermore, the firmware in the Tiny45 is well-written in C language and compiled with Winavr and USB source code from obdev.
If you’re referring to the above figure, you might find out that there is no crystal, as the software sync the internal 16.5MHz PII clock with the USB clock!
The device is designed to plug into a project breadboard. In this case, there is no need for you to apply a power supply on it. The dual trace scope can be connected directly to a PC with USB in HID mode, without needing to install any specific driver.