Confused Noob on Logic Analysis capabilities of Osciliscopes DHO914S - Page 1
Forum section: electronics / testgear

author: simonboydfoley
author_rank: Contributor
timestamp: January 04, 2024, 02:24:29 am
content: Hi Guys,a muppet here trying to save some time and avoid traps for new players. I'm interested in analyzing SPI and CAN bus signals and I have used cheap signal analyzers from amazon that connect to my PC and work OK. I have a basic Hantek oscilloscope that I hacked and ..... yeh it like the village bicycle ... I want to upgrade, and I was looking at the DHO914S that has an integrated logic analyzer ... but when I search for the cable that connects to the logic analyzer on this scope PLA2216 .... I get quotes for 400-500 GBP just for the cable that connects to the oscilloscope ..... Am I going nuts ? My open source sigrok solution setup is a fraction of the cost at 20-50 GBP and yet these guys want 400-500 GBP for a cable that I can probably make myself using my 3d printer ?Am I being stupid ?

author: Kean
author_rank: Unknown
timestamp: January 04, 2024, 02:49:14 am
content: Search the forum for PLA2216 and you will find a few DIY options.

author: Fungus
author_rank: Super Contributor
timestamp: January 04, 2024, 03:06:40 am
content: Quote from: simonboydfoley on January 04, 2024, 02:24:29 amNope.They're not just cables, have high speed comparators in them with programmable threshold voltages, but the price is still a bit of a ripoff.

author: mwb1100
author_rank: Frequent Contributor
timestamp: January 04, 2024, 04:29:26 am
content: Quote from: Kean on January 04, 2024, 02:49:14 amThere are also clones available on eBay for around $80 USD. Likely based on the DIY threads here. I can't vouch for the quality, so do whatever due diligence you need before you decide to take the plunge.

author: pickle9000
author_rank: Super Contributor
timestamp: January 04, 2024, 04:51:54 am
content: You can do serial decoding without the PLA2216.

author: ebastler
author_rank: Super Contributor
timestamp: January 04, 2024, 10:15:00 am
content: Quote from: mwb1100 on January 04, 2024, 04:29:26 amThe low-cost solution on ebay does not have the proper comparators, but just standard CMOS-to-differential-pair drivers. I.e. it is not possible to set the low/high threshold via the scope software, but it is fixed at 1.5 V or so -- which is OK if you only want to probe 3.3V and 5V logic. It also comes with a more bulky, standard ribbon cable and cheap grabbers, so the ergonomics are worse than with Rigol's solution.I first thought "ripoff!" as well when I saw Rigol's price. But if you look at the cost of building a DIY solution with the same comparators and quality grabbers, it turns out you can't save that much (if you want the full functionality and quality).

author: Mechatrommer
author_rank: Super Contributor
timestamp: January 04, 2024, 11:50:42 am
content: Quote from: simonboydfoley on January 04, 2024, 02:24:29 amits not just cable, its called logic probe.. as others have mentioned, it got 8pcs LMH7322 in it, costed me $100 of money damage from Mouser just on the chips, 3d printed enclosure is another story, the chip size 4mm x 4mm and try to solder it on pcb is another more story... as others have mentioned too, you dont need it if all you want is to decodeserialdata... you dont even need the DHO"S"model. the LA probe only for parallel 16 bits, and GUI is pretty basic on the S model. here there thread they talked about...https://www.eevblog.com/forum/testgear/rpl1116-active-logic-probe-pod-for-1000z-series-teardown/ymmv.

author: simonboydfoley
author_rank: Contributor
timestamp: January 04, 2024, 12:40:13 pm
content: Thanks for the help guys appreciatedI'll do some more digging to see if its worth paying for the logic analyzer capabilities in the scope or sticking with my Sigrok solutions :-)most of my stuff is Arduino / Pico SoC GPIO SPI & 3D Printing Canbus analysis so we would be looking 3-5v.

author: simonboydfoley
author_rank: Contributor
timestamp: January 05, 2024, 03:21:41 am
content: After doing some digging and reading the manual I can get away with the onboard 4 channel decoding of SPI (My old Hantek DSO5102P series Scope only had 2 Channels) , as you guys have stated I don't need to use the LA interface for what I am doing. This means I don't need to buy the PLA2216.I have ordered the DHO914S so I always have the option in the future of using the LA if I need more logic channels and the onboard AFG means I can save some more desk real estate.I suspect I can hack it to 250MHz like I hacked the Hantek to 200MHz.This unit is perfect I can connect it to my microscope monitor via HDMI as well for my failing eyesightThanks for all your help .... really appreciated ... its going to be a revelation to have a decent scope ....the Hantek barley got me by :-)

author: Mechatrommer
author_rank: Super Contributor
timestamp: January 05, 2024, 03:30:27 am
content: Quote from: simonboydfoley on January 05, 2024, 03:21:41 amdefinitely can! ignore the siglent naysayers spitting bullsheet about aliasing...https://www.eevblog.com/forum/testgear/hacking-the-rigol-dho800900-scope/https://www.eevblog.com/forum/testgear/rigol-dho804-bode-plot