Hi Everyone!

Would need your advice on which Micro controller that i should use to build a PC-USB based oscilloscope, i would need to have high sampling rate, maybe 100M, but based on my search online,most of the board can only handle less than 10M, onboard ADC can only do 200K e.g. beagle bone, sorry, i might be wrong.

Do your guys have any recommendation for this?

Thanks!!!!

 

Hi,

I don't have a recommendation for 100M sample rate. However, you can get the equivilent of 100M by using a lower sample rate and "Repetative" sampling, if your signal is periodic.

 

People have done this a hundred times. Why are you trying to re-invent the wheel? It's not an easy project; it's high performance and requires advanced analog and digital knowledge. If you're just dropping into this board and saying, "what should I use for this" you may not have the chops to do it. But learning about it is always good so here are some resources.

Google "USB Oscilloscope" and you'll find a lot of them. Here's one with a dsPIC processor. But I think it's only 1Msps.
http://www.instructables.com/id/DIY-USB-OSCILLOSCOPE-IN-A-MATCHBOX/

I think to get 100Msps you'd have to use an outboard high-speed ADC. I don't think any microcontroller has a 100Msps ADC.

This page describes a 40Msps scope among other things. It has a lot of resources.
http://www.opencircuits.com/Oscilloscope

 

What will you use for the ADC? Do you plan to use an MCU with such a rapid sampling ADC built in? How many bit resolution do you plan to have. That might affect the processor choice.

Anyway, a thread was started at ElectroTech a few years back. It was a cooperative design-build for an oscilloscope that got almost to the finish line, but then died. Most of the good stuff is around page 3. Here's a link: http://www.electro-tech-online.com/threads/coop-build-scope-probe.130742/

John

 

Do your guys have any recommendation for this?

Put 100 such mcus, each sampling at 1Msps successively. You have got yourself a 100Msps device.

The highest sampling rate mcu I have seen is LPC437x series, capable of 80Msps. Analog or Freescale are your other choices, without going to dedicated adcs.

 

http://www.mouser.com/ProductDetail...Fd/fuLqZPt6I39%2b11MvJJbLiV2GqqgI/%2b4X0BDw==

24 bucks.