Build A Simple USB Digital Logic Analyzer

Purpose: For someone learning digital electronics and needing to see the waveforms of counters/shift registers or any other digital signal, you can build this simple USB circuit with easily available few parts.


Requirements: What Do I Need To Get Started?

The following table shows the main parts needed:

Quantity Part Number Description
1 PIC18F4550 MICROCHIP 8 Bit Microcontroller (or any other development kit which can use this MCU)
1 62256 32K x 8-bit SRAM memory (Any manufacturer with that number as their part number will do)
Note: If you don't have any 62256, you may use other compatible 32k x 8 static RAM chips
like the Cypress CY7C199. Even if the pinout is not exactly the same, it will still work.
1 74LS244 Octal Buffers and Line Drivers with 3-State Outputs
(Any variation of 74244 will do)
1 10k Pull-up resistor
Any other components will depend on how the circuit is to be built.
You will need a basic setup for working with PIC devices. You can use any PIC programmer such as MPLAB IDE or the more recent MPLABX IDE/IPE.
I used the PICDEM FS USB Demo board, PICkit 3 and MPLAB IDE V8.92 from Microchip while developing the project.



Here are all the necessary files to do the project:
Digital Logic AnalyzerVer2.pdf - PDF file of the schematic
18F4550HEXHIDAgent.zip - PIC18F4550 MPLAB HEX file and HID Agent OCX
*** IMPORTANT *** You must first install the HID Agent ActiveX control
before installing the Digital Analyzer VB.NET program.
Using the MS-DOS Command Prompt, go to the folder
where you extracted the above ZIP file and execute
the following command (not case sensitive):
RegSvr32 HIDagentXControl1.ocx
Note: Make sure you have Admin priviliges
or else it will not succeed.
Install Digital Analyzer VB.NET program.

Contact Info: marcpic13@yahoo.com