Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Equipment & Tools From test equipment to hand tools

PC USB scope project.
PC USB scope project.
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 7th July 2019, 03:59 AM   #41
astromo is offline astromo  Australia
diyAudio Member
 
Join Date: Nov 2017
Location: BFN
Kudos to you.

Looks like you've made some serious progress.

Nice.
  Reply With Quote
Old 7th July 2019, 04:06 AM   #42
nigelwright7557 is offline nigelwright7557  United Kingdom
diyAudio Member
 
nigelwright7557's Avatar
 
Join Date: Apr 2008
Location: Carlisle, England
Quote:
Originally Posted by astromo View Post
Kudos to you.

Looks like you've made some serious progress.

Nice.
I am currently getting a new pcb made in China and they are going to solder the microcontroller and fast external A2D for me. I will do the rest as its still through hole. I will probably go to all SMD at some point.
I just build on the previous version of software for the faster version.
The external A2D is easier than using the one on the microcontroller as its just reading a port as fast as possible and dumping data into RAM. Its then sent out via USB.
__________________
PCBCAD51 download or CDROM 2019 version out now https://www.murtonpikesystems.co.uk
  Reply With Quote
Old 7th July 2019, 09:40 AM   #43
astromo is offline astromo  Australia
diyAudio Member
 
Join Date: Nov 2017
Location: BFN
Kool as bro'

I haven't gone down the path of an O'scope yet. No rush. But when the time comes, it would be heart warming to back "home grown" .. if you get my drift.

Keep the updates coming..

Last edited by astromo; 7th July 2019 at 09:50 AM.
  Reply With Quote
Old 10th July 2019, 01:05 AM   #44
Bigun is offline Bigun  Canada
diyAudio Member
 
Bigun's Avatar
 
Join Date: Jan 2009
Location: Waterloo, ON or Herefordshire UK
PC USB scope project.
Wow, I've seen a lot of stuff from you Nigel, have to say that you are a multi-talented guy!
__________________
"The test of the machine is the satisfaction it gives you. There isn't any other test. If the machine produces tranquility it's right. If it disturbs you it's wrong until either the machine or your mind is changed." Robert M Pirsig.
  Reply With Quote
Old 10th July 2019, 03:05 AM   #45
anatech is offline anatech  Canada
diyAudio Moderator
 
anatech's Avatar
 
Join Date: Jun 2004
Location: Georgetown, On
PC USB scope project.
Nigel,
Very impressive! Keep the updates coming. This is very interesting.

-Chris
__________________
"Just because you can, doesn't mean you should" my Wife
  Reply With Quote
Old 11th July 2019, 02:40 AM   #46
nigelwright7557 is offline nigelwright7557  United Kingdom
diyAudio Member
 
nigelwright7557's Avatar
 
Join Date: Apr 2008
Location: Carlisle, England
Still waiting for my new usb scope hardware to arrive.
So got my previous version out and started writing code on it for my new hardware.
I was a bit disappointed to find I could only get about 4MHz sampling rate.
After a little help from Microchip forums I managed to get it up to 10MHZ but that looks about the limit for the microcontroller I am using. While it is 200MHz it doesn't run code that fast. It seems to run about a fifth of that speed so I guess it must be about 5 clock cycles per instruction.
I have to clock out data from the a2d so it takes time to clock the I/o pin and then read the i/o port then store the data in a memory buffer.
__________________
PCBCAD51 download or CDROM 2019 version out now https://www.murtonpikesystems.co.uk
  Reply With Quote
Old 11th July 2019, 02:11 PM   #47
anatech is offline anatech  Canada
diyAudio Moderator
 
anatech's Avatar
 
Join Date: Jun 2004
Location: Georgetown, On
PC USB scope project.
Hi Nigel,
It looks like you're going to have to use another A/D converter and use the PIC products for control and maybe features. The PIC could run math functions on the data before displaying it. If you use a small PIc for overall housekeeping and functions & range selections, then the faster PICs for math functions and display you could end up with one heck of a nice 'scope.

-Chris
__________________
"Just because you can, doesn't mean you should" my Wife
  Reply With Quote
Old 11th July 2019, 07:11 PM   #48
jan.didden is online now jan.didden  Europe
diyAudio Member
 
jan.didden's Avatar
 
Join Date: May 2002
Location: Westende Resort, BE coast
Quote:
Originally Posted by nigelwright7557 View Post
Still waiting for my new usb scope hardware to arrive.
So got my previous version out and started writing code on it for my new hardware.
I was a bit disappointed to find I could only get about 4MHz sampling rate.
After a little help from Microchip forums I managed to get it up to 10MHZ but that looks about the limit for the microcontroller I am using. While it is 200MHz it doesn't run code that fast. It seems to run about a fifth of that speed so I guess it must be about 5 clock cycles per instruction.
I have to clock out data from the a2d so it takes time to clock the I/o pin and then read the i/o port then store the data in a memory buffer.
Most PICs use 4 clock cycles per instruction. Also, this type of high-connectivity chips have programmable clock-wait-cycles in their data I/O operations. Maybe you can change the defaults to run it faster, there's several registers involved.
Never used this one but looked at it some time ago for another project.

Jan

Jan
__________________
Cable: a potential source of trouble interconnecting two other potential sources of trouble - Erik Margan
Linear Audio pubs and articles . The SilentSwitcher now at diyaudio store SilentSwitcher. Keeping in touch with SY.

Last edited by jan.didden; 11th July 2019 at 07:16 PM.
  Reply With Quote
Old 11th July 2019, 07:35 PM   #49
phofman is offline phofman  Czech Republic
diyAudio Member
 
Join Date: Apr 2005
Location: Pilsen
I have absolutely no experience with these MCUs - but the parallel master port + DMA combination looks like the best performing way of parallel data transfer

e.g. Embedded Engineering : PIC32MX DMA Performance Test , PMP Parallel Master Port DMA Performance (Specifically PIC32MX470F512H) 10MHz x 32bit rate with 120MHz MCU.

I have no idea if that is practically viable for the transfer from the ADC.
  Reply With Quote
Old 11th July 2019, 10:16 PM   #50
nigelwright7557 is offline nigelwright7557  United Kingdom
diyAudio Member
 
nigelwright7557's Avatar
 
Join Date: Apr 2008
Location: Carlisle, England
Using best discrete code so far I can get 12.5MHz sampling rate.
I don't think PMP or DMA would do it much faster as they still use same PIC bus.
__________________
PCBCAD51 download or CDROM 2019 version out now https://www.murtonpikesystems.co.uk
  Reply With Quote

Reply


PC USB scope project.Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
New project 1megasample/second PC USB scope project. nigelwright7557 Digital Line Level 0 14th July 2018 10:42 PM
DSO150 - a poor 'scope, but is it enough 'scope? bugbear Equipment & Tools 14 5th June 2018 03:13 PM
New project USB scope. nigelwright7557 Equipment & Tools 12 6th February 2017 05:59 PM
USB Scope - Real scope and not too expensive Algar_emi Equipment & Tools 11 16th March 2010 11:40 PM
Great deal on Digital scope. Is this enough scope? hifimaker Pass Labs 1 1st May 2007 09:59 PM


New To Site? Need Help?

All times are GMT. The time now is 09:14 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki