Hai mo.khairy.mo
Here is the description of USB based oscilloscope using PIC 18F2550. The complete kit including PCB, Programmed microcontroller, schematics,other passive components and the project deccription is vailable from www.united77.com/projects.htm.
Two-Channel PC Based Oscilloscope using USB port of the PC that operates at up to 10 kHz with ±16V input voltage. The oscilloscope uses IC PIC18F2550 microcontroller chip from Microchip as the main controller, which makes the oscilloscope compact as there is no need of additional power supply for the entire circuit board. This controller chip along with MCP6S91, LF353 and L7660 ICs are used in the project.
i need schematic of this circuit . i want to design this. i cant download in this website www.united77.com/projects.html.This controller chip contains MCP6S91, LF353 and L7660 & pic18f2550. plz help me