Rigol DS1054z 1 wire signal capture - Page 1
Forum section: electronics / testgear

author: scobay
author_rank: Newbie
timestamp: October 17, 2018, 12:09:49 pm
content: Hi I recently upgraded my rigol 1052e for a DS1054z I used to be able to the the Dell laptop signal ps_Id on my old scope but I am unable to capture the signal n the ds1054z. I believe this comes from within the charger from a Dallas chip using the 1 wire protocol. I dont need to decode the protocol just be able to see the signal is present for charging the battery.I haven't got the hang of the scope yet so any pointers would be great.

author: Fungus
author_rank: Super Contributor
timestamp: October 17, 2018, 01:48:50 pm
content: The procedure should be the same.What settings are you using?

author: scobay
author_rank: Newbie
timestamp: October 17, 2018, 03:49:01 pm
content: I have tried everything to no avail, I have copied the setting from this screen grab but I cannot see the signal (even on auto)

author: StillTrying
author_rank: Super Contributor
timestamp: October 17, 2018, 04:10:26 pm
content: "I have copied the setting from this screen grab but I cannot see the signal"Does the trace at least move up to the 3.3V level, or does it stay at the 0V marker level.Does the channel show the scopes own 1kHz 3V test.Is the probe and scope channel on X10.If you're using a new probe's witches hat clip they sometimes need more than expected force before they click and make contact.

author: Fungus
author_rank: Super Contributor
timestamp: October 17, 2018, 04:33:09 pm
content: Quote from: StillTrying on October 17, 2018, 04:10:26 pmThis seems likely if there's no signal at all. You have to press quite hard to get the clips to click into place.

author: scobay
author_rank: Newbie
timestamp: October 17, 2018, 04:35:10 pm
content: HI yes it jumps to 3.2v but no matter what I do I cannot get a signal from it

author: scobay
author_rank: Newbie
timestamp: October 17, 2018, 04:38:47 pm
content: I can get the test signal and various signals from around the board , clk/data but the ps_id sigal I cannot get

author: StillTrying
author_rank: Super Contributor
timestamp: October 17, 2018, 05:34:54 pm
content: If you've got the trigger on the same channel, the trigger level at about +1.5V, and the X trigger position at the center of the screen, I can't think of much else!Peak-detect and roll mode, to at least see if the signal is there?

author: kcbrown
author_rank: Frequent Contributor
timestamp: October 17, 2018, 06:42:31 pm
content: Check your triggering setup. From the image you posted from your 1052E, it appears that you'll want edge detect triggering on the falling edge (since it appears the signal is active-low), with a 1ms holdoff.What areallof your settings for the trigger? A screenshot of them from your 1054Z might help clarify things.Oh, and you probably want "normal" trigger mode for this, not "auto", so that you see only the signal.

author: scobay
author_rank: Newbie
timestamp: October 17, 2018, 08:18:44 pm
content: Seems to be it only pulses when power is supplied and I cant seem to acquire the signal as its too fast and I cannot figure out how to grab it.

author: TK
author_rank: Super Contributor
timestamp: October 17, 2018, 08:24:24 pm
content: Maybe you should try trigger in NORMAL mode?

author: scobay
author_rank: Newbie
timestamp: October 17, 2018, 08:44:36 pm
content: I changed the sweep to normal mode and I get this waveform

author: TurboTom
author_rank: Super Contributor
timestamp: October 17, 2018, 09:22:13 pm
content: You've also delayed the time base considerably so you actually never saw the trigger instant. Just press the "horizontal position" knob once and the trigger marker is right on-center and the triggering event should be visible.

author: kcbrown
author_rank: Frequent Contributor
timestamp: October 17, 2018, 10:00:56 pm
content: Quote from: scobay on October 17, 2018, 08:44:36 pmGood. The reason it looks different from your 1052E is that you have the timebase set to 50us instead of 500us, and you have the vertical sensitivity set to 2v/div instead of 1v/div. If you change those two things, you'll get something that looks similar to what you saw on your 1052E.It won't look identical, because it appears you had your trigger set up to look for rising edges on your 1052E, but it'll be close enough (given the signal, it looks like falling edge triggering is more appropriate for this signal, which is why I suggested it in the first place).

author: scobay
author_rank: Newbie
timestamp: October 18, 2018, 01:45:47 pm
content: Many thanks , I have a bit better understanding of it now. Basically I though this was a repeating signal so I was missing it as it only occurs once (When you plug in the adapter).