Page 1 of 2

Re: More temperature probes!

Posted: Sat Sep 28, 2013 5:37 pm
by Piper
Roberto,

Still not much luck on this. I tried a 10K resistor and a 4K7 (after doing some research on the probes) and I still get that two tenths of a degree fluctuation after about 15 minutes.

Looking at the Eagle file for the head unit, wouldn't R29 (2K2) act as my pull-up resistor in this case? In theory, I should simply be able to plug my hub in (like you originally stated) and have a pull-up resistor automagically "built in" based on my very limited electronics experience. Looking at the eagle file it looks like that is all you're doing with the two right-hand connectors, correct?

I also tried parasite-powering the probes by tying the ground the the vcc (with a 4K7 resistor between the vcc and the data) on the probes. Still getting the same results.

Any other suggestions?

~Charlie

Re: More temperature probes!

Posted: Sat Sep 28, 2013 7:52 pm
by rimai
The 2ke is the pull up I use on the board, but when the extension is too far, the cable has a natural capacitance that makes the signal too sluggish and causes it not to work properly.
I have made temp probe hubs in the past with a 10K resistor in the hub end and it worked fine.

Re: More temperature probes!

Posted: Wed Oct 02, 2013 8:05 am
by Piper
I'm not sure what my issue is on this but I made a little progress last night. I went back to a 10K resistor and that seemed to help slightly. What's interesting is that if I plug a probe in the port closest to the pH BNC jack and then plug the hub into the middle port it seems to work much better. I get a little fluctuation but not like I was before. It might even be a legitimate fluctuation as it was only in one of the probes (open to the air) and not as rapid as before.

This just has me scratching my bald spot. I can't see how the hub is any different than the two right hand ports on the head unit looking at the Eagle file. I'll keep monkeying around with it and let you know if I figure it out.

~Charlie

Re: More temperature probes!

Posted: Mon Oct 07, 2013 6:50 am
by Piper
Roberto,

It's my PWM Dimming addon module that is causing the problem with the temp probes. I was always working on this in the evening after work. I finally caught on to the fact that it started going wonky when the main lights went out and the moonlights came on. I disconnected the dimming module and the temp probe hub works fine.

Now when I try to reconnect the dimming module all the moonlights blink on/off. Similar to how the temps would fluctuate in fact. Any ideas on what could be going on here?

~Charlie

Re: More temperature probes!

Posted: Mon Oct 07, 2013 8:00 am
by rimai
Strange.
Where are the moonlights connected? Std channels?
What is the AP/DP showing?
Can you measure voltage and confirm the same fluctuation?
What happens if you disconnect your temp hub? Does the moonlight stop doing it?

Re: More temperature probes!

Posted: Mon Oct 07, 2013 8:32 am
by Piper
Strange.
Agreed :)
Where are the moonlights connected? Std channels?
I think they're on ports 1, 2, & 3 on the PWM expansion but can't be 100% sure till I get home and look at it again.
What is the AP/DP showing?
They're fine. They are running my two Jebao pumps and no issues there.
Can you measure voltage and confirm the same fluctuation?
Will do. I'll check that tonight when I get home and let you know.
What happens if you disconnect your temp hub? Does the moonlight stop doing it?
No. Now any time I plug in the PWM module (no matter if they're on or off in the code) it just makes the moonlights blink.

I'll post back tonight with the voltage reading. I'll also try a different USB cable to see if that helps as well.

~Charlie

Re: More temperature probes!

Posted: Wed Oct 09, 2013 6:59 am
by Piper
Can you measure voltage and confirm the same fluctuation?
Each port jumps all over the place from ~1.4v the just under 2V. The green led on the front of the PWM addon also flashes sporadically with the voltage.

I want to try one more thing tonight when I get home. I want to plug the PWM module directly into the main relay box and eliminate the expansion hub. I'm 90% sure it's my PWM module but I just want to rule out the expansion hub.

~Charlie

Re: More temperature probes!

Posted: Wed Oct 09, 2013 7:40 pm
by Piper
Definitely the PWM dimming module. Same results hooked up to the main relay or expansion hub. Anything I can try at home or do I need to send it in for you to look at?

~Charlie

Re: More temperature probes!

Posted: Wed Oct 09, 2013 8:48 pm
by rimai
Are the other channels working and only the moonlight channels acting up?

Re: More temperature probes!

Posted: Wed Oct 09, 2013 9:11 pm
by Piper
All ports acting up. I removed the moonlights to test too and same results.

Re: More temperature probes!

Posted: Wed Oct 09, 2013 9:29 pm
by rimai
Bring it with you this weekend to BAP.
I'll be there.

Re: More temperature probes!

Posted: Thu Oct 10, 2013 7:10 am
by Piper
Will do. Thanks, Roberto!

Re: More temperature probes!

Posted: Thu Oct 10, 2013 7:18 am
by Piper
It's the 19th; next weekend. I'm doing a presentation on DBTC that I was planning to put that together this weekend. You had me worried there for a minute :)

~Charlie

Re: More temperature probes!

Posted: Thu Oct 10, 2013 8:44 am
by rimai
Thank God we had this discussion.
I thought it was this weekend and would be hitting a closed door when I got there... :evil:
The week after it is then... See ya there

Re: More temperature probes!

Posted: Mon May 04, 2015 5:28 pm
by joshlawless
Sorry to resurrect an old, old thread, but does "splicing" another temperature probe mean just connecting it via a 3-pin Y-cable? Can't understand how that would work, but happy to hear it if so. I have four temperature probes, and only three headers. Would love to get the fourth one onto the bus, but not quite up to ordering any more custom PCBs right now.

Re: More temperature probes!

Posted: Mon May 04, 2015 8:23 pm
by rimai
Yes, Y cable works :)

Re: More temperature probes!

Posted: Mon May 04, 2015 8:30 pm
by joshlawless
Awesome!

Re: More temperature probes!

Posted: Mon May 18, 2015 4:39 pm
by joshlawless
Is this the right code to access the value of the fourth probe?

Code: Select all

ReefAngel.Params.Temp[T4_PROBE]

Re: More temperature probes!

Posted: Mon May 18, 2015 5:18 pm
by rimai
yes

Re: More temperature probes!

Posted: Mon May 18, 2015 6:16 pm
by Sacohen
Following.
I may want to add another temp probe to my salt mixing station.

Re: More temperature probes!

Posted: Fri Jun 05, 2015 8:39 am
by ewaldsreef
Do you add the code in setup?

Re: More temperature probes!

Posted: Fri Jun 05, 2015 8:49 am
by rimai
Yes.