More temperature probes!

Request new hardware or ideas for the controller
User avatar
joshlawless
Posts: 138
Joined: Thu May 23, 2013 2:52 pm

More temperature probes!

Post by joshlawless »

It seems as though no matter how complicated your reef angel setup, there's an upper limit on the number of temperature probes you can monitor, since only the head unit includes ports for attaching temperature probes.

Please consider adding support for more temp probes. For example, you could include a temp probe port on the pH or ORP or salinity expansion modules (similar to what Neptune does with their probe expansion hardware). Alternatively, you could release a stand-alone temp probe expansion, which would hopefully be fairly cheap, given the simplicity.

Areas where it's helpful to monitor temperature:

temperature of water in display tank
temperature of water in refugium
temperature of water in additional connected/nearby tanks (QT, hospital)
temperature of air in enclosed canopy
temperature of air in enclosed stand
temperature of heat sink in DIY LED build
etc. etc.
User avatar
lnevo
Posts: 5430
Joined: Fri Jul 20, 2012 9:42 am

Re: More temperature probes!

Post by lnevo »

The topic has been discussed a few times. You can splice in more temp probes and I believe theres an installation out there the has quite a few. I know its not so plug and play but maybe it would be easy to just create a y cable that would let you plug in more much easier than splicing...
User avatar
joshlawless
Posts: 138
Joined: Thu May 23, 2013 2:52 pm

Re: More temperature probes!

Post by joshlawless »

I searched the forum, and have seen posts indicating that it is possible to mod the head unit to support more probes, but am unclear as to how. As I understand it, the temperature probe is a thermistor, and I can't imagine how you could arrange multiple resistors on the same port while still being able to separately monitor their resistance. Any further clarity you can shed on this issue would be much appreciated.
rimai
Posts: 12881
Joined: Fri Mar 18, 2011 6:47 pm

Re: More temperature probes!

Post by rimai »

It's currently software limited to 3 probes. It's not a hardware limitation.
The hardware limitation is easy to overcome.
More probes can be added to the bus, which is capable of reading a whole bunch. 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.
The probes are not thermistors. They are digital temperature sensors with unique serial ID.
So you can address every single one of them in the same bus.
The chip used is DS18B20.
Roberto.
Piper
Posts: 296
Joined: Fri Jul 20, 2012 7:13 am
Location: Oakley, CA

Re: More temperature probes!

Post by Piper »

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
rimai
Posts: 12881
Joined: Fri Mar 18, 2011 6:47 pm

Re: More temperature probes!

Post by rimai »

Yes :)
Roberto.
wideawake
Posts: 29
Joined: Mon May 20, 2013 3:55 am

Re: More temperature probes!

Post by wideawake »

Hi guys,
I have some spare DS18B20 temperature probes at home. The ones I have, have wires coloured Red/Black/Blue. The probe that came with RA was Red/Black/White. I wired the Blue to take the white wire place on a 3 pin connector.

But when I plug it in, the controller display blacks out and all the relay turns off. Any idea what's happening? How can I determine the right wire color?

Thanks.
rimai
Posts: 12881
Joined: Fri Mar 18, 2011 6:47 pm

Re: More temperature probes!

Post by rimai »

Don't use the colors.
The pinout can be found in the eagle files, but if you are looking at the header pins pointing at you, they are:
left-> GND
middle-> Data
right-> +5VDC
Roberto.
mkoryto
Posts: 7
Joined: Tue Mar 19, 2013 8:35 pm

Re: More temperature probes!

Post by mkoryto »

I would purchase a connector/expansion that would allow extra temp probes (6) if one was available. I would think others would too. You can never have too many temp probes!
wideawake
Posts: 29
Joined: Mon May 20, 2013 3:55 am

Re: More temperature probes!

Post by wideawake »

rimai wrote:Don't use the colors.
The pinout can be found in the eagle files, but if you are looking at the header pins pointing at you, they are:
left-> GND
middle-> Data
right-> +5VDC
Got it working. Thanks Roberto!
User avatar
jsclownfish
Posts: 378
Joined: Mon Oct 24, 2011 7:52 pm
Location: Saint Louis

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
Posts: 296
Joined: Fri Jul 20, 2012 7:13 am
Location: Oakley, CA

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
Piper
Posts: 296
Joined: Fri Jul 20, 2012 7:13 am
Location: Oakley, CA

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
Posts: 12881
Joined: Fri Mar 18, 2011 6:47 pm

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.
Piper
Posts: 296
Joined: Fri Jul 20, 2012 7:13 am
Location: Oakley, CA

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
Piper
Posts: 296
Joined: Fri Jul 20, 2012 7:13 am
Location: Oakley, CA

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
Posts: 12881
Joined: Fri Mar 18, 2011 6:47 pm

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.
Piper
Posts: 296
Joined: Fri Jul 20, 2012 7:13 am
Location: Oakley, CA

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
Posts: 12881
Joined: Fri Mar 18, 2011 6:47 pm

Re: More temperature probes!

Post by rimai »

Ahhh....
Add a 10K resistor to your hub between VCC and DATA
Roberto.
Piper
Posts: 296
Joined: Fri Jul 20, 2012 7:13 am
Location: Oakley, CA

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!
Piper
Posts: 296
Joined: Fri Jul 20, 2012 7:13 am
Location: Oakley, CA

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
Posts: 12881
Joined: Fri Mar 18, 2011 6:47 pm

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.
Piper
Posts: 296
Joined: Fri Jul 20, 2012 7:13 am
Location: Oakley, CA

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
Piper
Posts: 296
Joined: Fri Jul 20, 2012 7:13 am
Location: Oakley, CA

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
Posts: 12881
Joined: Fri Mar 18, 2011 6:47 pm

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.
Piper
Posts: 296
Joined: Fri Jul 20, 2012 7:13 am
Location: Oakley, CA

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
Piper
Posts: 296
Joined: Fri Jul 20, 2012 7:13 am
Location: Oakley, CA

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
Piper
Posts: 296
Joined: Fri Jul 20, 2012 7:13 am
Location: Oakley, CA

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
Posts: 12881
Joined: Fri Mar 18, 2011 6:47 pm

Re: More temperature probes!

Post by rimai »

Are the other channels working and only the moonlight channels acting up?
Roberto.
Piper
Posts: 296
Joined: Fri Jul 20, 2012 7:13 am
Location: Oakley, CA

Re: More temperature probes!

Post by Piper »

All ports acting up. I removed the moonlights to test too and same results.
Post Reply