More temperature probes!

Request new hardware or ideas for the controller
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jsclownfish
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Re: More temperature probes!

Post by jsclownfish »

It' s not as simple a solution, but if you upgraded to the RA+ like I did, you can use the original RA to read some extra temps (3) or even pH and sent it to the main over I2C.

-Jon
Piper
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Re: More temperature probes!

Post by Piper »

Piper wrote:
rimai wrote:Simply by splicing it or creating a simple breakout board that would do the split for you.
I'll put something together for the breakout and change the libs to be able to be initialized with more probes.
So I can put something together on a Veroboard that will split out four or more additional probes and plug that into one of the existing connectors, correct? I know need to update the software too. I want one more probe for to monitor my W/C water so I might as well make room for a few more while I'm at it.

~Charlie
Roberto,

I soldered up a 4-port "temp probe hub" last weekend and plugged it into one of the ports on my RA head unit. I did it mainly as an extension cord for the current probes with the idea that I can add more later when I have time to dig in to the libraries.

I ran into some problems with it though. When I had all three probes plugged into the "hub" the temps would fluctuate up and down a few tenths of a degree every second or two. That was causing the relays for my heaters and fans to repeatedly kick on and off.

Is there anything special I need to do to the libs to get this to work? I thought the changes needed to the libs were only to get the RA to recognize more than 3 probes.

~Charlie
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Re: More temperature probes!

Post by Piper »

I might have a bad solder on one of the ports or I possibly neglected to reboot after plugging in the probes. I moved the temp probes around on the hub and rebooted and it seems to be working correctly now.

~Charlie
rimai
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Re: More temperature probes!

Post by rimai »

Nothing on the libs.
You are correct that the change in the libs was neeeded for more than 3 probes support.
Glad you got it working :)
Roberto.
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Re: More temperature probes!

Post by Piper »

rimai wrote:Glad you got it working :)
It was short lived :/ Within about an hour it was getting all wonky on me again. I'll take a closer look at the board when I get home tonight and make sure I'm not shorting out somewhere and/or didn't cross a wire.

~Charlie
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Re: More temperature probes!

Post by Piper »

Still no luck with this. All the solders looked good. I also tried it on a breadboard just to make sure and it still gets wonky after about 15 - 45 minutes. The temps only fluctuate 2 - 4 tenths of a degree but it's enough (on my setup at least) to keep triggering the relays.

Is it possible that I'm still having I2C issues on my setup? I suppose I can try unplugging the expansion hub tonight and eliminate all the add-ons to test that.

~Charlie
rimai
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Re: More temperature probes!

Post by rimai »

The temp probes don't use I2C.
They use OneWire.
And I'm taking the fluctuation doesn't happen when the probes are connected straight into the head unit, right?
Roberto.
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Re: More temperature probes!

Post by Piper »

Correct, no rapid fluctuation when connected directly to the head unit. Just the expected temp fluctuations due to ambient temp. In fact, if I leave just one probe plugged in on the hub it doesn't fluctuate either.
rimai
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Re: More temperature probes!

Post by rimai »

Ahhh....
Add a 10K resistor to your hub between VCC and DATA
Roberto.
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Re: More temperature probes!

Post by Piper »

I just downloaded the Eagle file for the head unit and saw the resistors :) I'll try that tonight and let you know. Thanks!
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Re: More temperature probes!

Post 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
rimai
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Re: More temperature probes!

Post 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.
Roberto.
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Re: More temperature probes!

Post 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
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Re: More temperature probes!

Post 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
rimai
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Re: More temperature probes!

Post 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?
Roberto.
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Re: More temperature probes!

Post 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
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Re: More temperature probes!

Post 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
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Re: More temperature probes!

Post 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
rimai
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Re: More temperature probes!

Post by rimai »

Are the other channels working and only the moonlight channels acting up?
Roberto.
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Re: More temperature probes!

Post by Piper »

All ports acting up. I removed the moonlights to test too and same results.
rimai
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Re: More temperature probes!

Post by rimai »

Bring it with you this weekend to BAP.
I'll be there.
Roberto.
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Re: More temperature probes!

Post by Piper »

Will do. Thanks, Roberto!
Piper
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Re: More temperature probes!

Post 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
rimai
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Re: More temperature probes!

Post 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
Roberto.
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joshlawless
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Re: More temperature probes!

Post 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.
rimai
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Re: More temperature probes!

Post by rimai »

Yes, Y cable works :)
Roberto.
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joshlawless
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Re: More temperature probes!

Post by joshlawless »

Awesome!
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joshlawless
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Re: More temperature probes!

Post by joshlawless »

Is this the right code to access the value of the fourth probe?

Code: Select all

ReefAngel.Params.Temp[T4_PROBE]
rimai
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Re: More temperature probes!

Post by rimai »

yes
Roberto.
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Sacohen
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Re: More temperature probes!

Post by Sacohen »

Following.
I may want to add another temp probe to my salt mixing station.
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