USB PC oscilloscope projects.

[nigelwright7557]

My first USB PC scope was PIC18F4550 460K samples / second.
Worked very well.
My next version was a PIC32MX and ran at 1Mega samples / second.
Next version was a PIC32mz and ran at 2 mega samples per second.
This was a little more difficult as I had to get involved with fine scale SMD.
With a bit of practice I managed to solder them ok.

My current version is PIC32mz with AD9200 a2d and runs at 12.5 mega samples / second.
The pic software is mostly USB interface and the rest grabbing data from the a2d.
The PC end is the clever end with data screens and an fast fourier transform display.

[Mechatrommer]

Thanks for telling us how delicious your chocolate is.

[horo]

To ease your job of building the next version, please think about an EzUSB from Cypress (CY7C68013A). The processor pcb comes as "saleae clone" for some bucks from the friendly Chinese and is well documented, so you can concentrate on the analog frontend. If you look at e.g. Hantek6022 it's an easy task with much room for improvement. And you get the SW for free as a starting point for your own experiments.

[robert.rozee]

My next version was a PIC32MX and ran at 1Mega samples / second.

hi Nigel,
    i'm quite interested in this. for the past few days i've been mulling over ways to use a pic32MX170 as a low-end DSO, and this evening started looking into the Cypress device used in the saleae clones. my plans with the MX170 were to use the internal RAM to hold around 50kpts of samples, and send them back to the host over a serial-to-usb bridge.

how adaptable would your pic32 software be for use on a pic32MX270 - with the ADX MUX controlled from the host PC? this would have potential for a single-chip (in DIP package) solution, connected via USB, with switchable input scaling via the MUX using little more than a few resistors in a chain.


cheers,
rob   :-)

[nigelwright7557]

since i started this thread i have gone onto pic32mx which runs at 200mhz
i used an analogue devices external a2d and can get up to about 25 mega samples/second.
great fun including trying to smd solder fine pitch ic's.