Help Identifying Instek GDS-2000E pin headers - Page 1
Forum section: electronics / testgear

author: rhb
author_rank: Super Contributor
timestamp: November 19, 2018, 11:48:55 pm
content: I am finally getting time to work on FOSS FW for Zynq based scopes. At present I have a GDS-2072E for a test platform. My first task, of course, is to understand the design and how to bare metal program it.I'm trying to sort out some connectors on the main board. In particular:J500J501 (not populated, but appears to be a USB PHY)J502J1170On my later production MSO-22004EA only J502 is populated.I need to find out how to reprogram the device when I brick it. I'm hoping I won't do that, but I want to be prepared. I've never attempted anything like this. So I'm assuming I'll brick it more than once. I have 30 years of DSP experience with a wide range of hardware and have built up a pretty good bench setup with budget for more T&M gear as needed. Most of the work will be done on a MicroZed or Zybo Z7-20, but at some point I'll need to start testing my FW on the 2072E.I'm hoping for something usable in 12 to 18 months. So don't hold your breathe. The DSP is easy, but I doubt that the FPGA dev tools are.There is a getty initiated on ttyPS0 (one of the two Zynq UARTs) in /etc/inittabI lucked out and got the GDS-2072E from Amazon for $244 delivered in one of their old stock selloffs. The Siglent SDS1202X is also Zynq based. So I'm looking for a similar deal on one of those. My goal is to write FW which is portable so that a port to a new scope is as easy as possible. I've also bought a Cyclone V based Terasic DE-10 Nano and will be testing my Verilog code on both Zynq and Cyclone V as I write it. I don't know of anyone using it in a DSO yet, but I learned a long time ago that the sooner you identify portability issues, the better.Any assistance on either the Instek or the Siglent would be a huge help. OEM technical documentation on either DSO would make it my primary target if someone can provide that. I can get an SDS1202X from Amazon for $380 delivered. I'd buy one in a heartbeat at that price if I had a schematic or service manual. Otherwise I'll take my time and look for a better price.My ultimate goal is to create a situation where an OEM can design a piece of HW and then just install a well supported FOSS FW rather than develop the FW themselves. It seems to me that both the OEMs and the users would greatly benefit. My fundamental model is what Gary Kildall did with CP/M. All an OEM had to do was write the BIOS routines and buy a copy of CP/M. In my case, I'm not looking for more money.

author: tautech
author_rank: Super Contributor
timestamp: November 20, 2018, 02:47:52 am
content: Quote from: rhb on November 19, 2018, 11:48:55 pmCorrection: SDS1202X-E is.QuoteThat's the current RRP:https://store.siglentamerica.com/product/sds1202x-e/All the documentation including a SM is here:https://www.siglentamerica.com/resources/documents/digital-oscilloscopes/#sds1000x-e-series

author: EEVblog
author_rank: Unknown
timestamp: November 20, 2018, 06:04:19 am
content: Quote from: tautech on November 20, 2018, 02:47:52 amWow, I had no idea Siglent released service manuals!

author: tautech
author_rank: Super Contributor
timestamp: November 20, 2018, 07:12:57 am
content: Quote from: EEVblog on November 20, 2018, 06:04:19 amNearly all products have service manuals Dave and those that don't, well they're under construction or being translated.

author: rhb
author_rank: Super Contributor
timestamp: November 20, 2018, 01:26:33 pm
content: Thanks. I'm quite impressed. There is actually useful information about test points. Unfortunately, for my purposes it does not include the JTAG or other programming headers.This is a huge improvement over the Siglent manuals when I was deciding on an MSO. I was strongly swayed by the quality of the GW Instek manuals. I read the Rigol, Siglent and Instek manuals until I thought I'd lose my mind. Siglent was dead last at manual quality, but obviously they recognized the issue and addressed it. GW doesn't offer a service manual at all, nor do they shield the SMPSU, so the EMI is horrible. I'm studying how to retrofit proper shielding on the GDS-2000E.Unfortunately, the MSO-2204EA did not live up to expectation in terms of FW or HW quality. But then neither the MSOX3104T or the RTM3104 at 10x the price met my expectations for FW QC.Most of the features of a DSO are the same. The integration of hard ARM cores into the FPGA provides a level of uniformity that it makes me think a CP/M style (i.e. device specific details isolated to the BIOS) DSO package under an LGPL license, so OEMs can focus their efforts on innovative functions for their HW is viable.Prior to the Zynq there were just too many permutations of CPU and FPGA for it too be sensible. This won't likely be viable for high end DSOs. But a 2 channel 200 MHz DSO for $380 list is a huge reduction in cost from the Tek 475.Lots of people don't understand that the ability to design HW, write a BIOS, license CP/M and go to market was what made the personal computer market explode. That continued with MS-DOS until programmers started writing to the bare hardware directly rather than using the BIOS and the HW had to be IBM compatible.I've been told this is impossible. You can't make it portable, it's more work than you can do, no OEM would adopt it, etc. But I made 500,000 lines of VAX FORTRAN code portable across 6 *very* different flavors of Unix by paying very close attention to always adhering to POSIX and the language standards. After cleaning up the many violations of F77 that the AIX compiler emitted warnings for, I was able do ports to DEC Ultrix and SGI IRIX as an afternoon lark. Most of the time was just waiting for it to compile.

author: tautech
author_rank: Super Contributor
timestamp: November 20, 2018, 06:51:33 pm
content: Quote from: rhb on November 20, 2018, 01:26:33 pmYou should find all you're looking for in Daves teardown:https://www.eevblog.com/2017/04/06/eevblog-985-siglent-sds1202x-e-oscilloscope-teardown/Do pay attention to the added preamble at the start.Dave tears down the 100 MHz model and sniffs the buss but then Siglent only releases the 200 MHz version to western markets.

author: nctnico
author_rank: Super Contributor
timestamp: November 20, 2018, 06:54:54 pm
content: Quote from: rhb on November 20, 2018, 01:26:33 pmBut it didn't bring much profit to IBM!

author: rhb
author_rank: Super Contributor
timestamp: November 20, 2018, 10:45:05 pm
content: Quote from: tautech on November 20, 2018, 06:51:33 pmThanks. I'll look at that again. I only had a general interest at the time. I think Siglent did the right thing.

author: rhb
author_rank: Super Contributor
timestamp: November 20, 2018, 10:52:25 pm
content: Quote from: nctnico on November 20, 2018, 06:54:54 pmWell, for several years if you wanted to run certain software it *had* to say IBM. So it gave them a pretty strong grip on the market.But my point is simply that by implementing a hardware abstraction layer as was done with the initial C version of Unix, most of the code can be very portable. That's true of a DSO as well.