reef-pi :: An opensource reef tank controller based on Raspberry Pi.

[ThorEp]

All guides use carbon film resistors. The main bill of materials has a resistor pack link from amazon. Which guide you are referring?

https://reef-pi.github.io/build-guides/temperature/ it shows a resistor in the drawings. Cant seem to find one in the description

 

[TMB]

I have also been looking at solutions for PH probes. I think the one listed above by @Gareth elliott is actually an analogue output, which would require conversion via ADC (MPC3008?) Gareth elliott, if these are different than the one you have please provide a link to that product.
Here are links to the probe, I think they are the same:
https://www.ebay.com/itm/Liquid-PH0...271985715879?_trksid=p2385738.m4383.l4275.c10
And here is a link to Data Sheet:
http://vi.vipr.ebaydesc.com/ws/eBay...descgauge=1&cspheader=1&oneClk=1&secureDesc=0
The addition of the PH probe is something that I'm willing to experiment with as well, hopefully I can help add to this great project.

 

[TMB]

@ThorEp

https://reef-pi.github.io/build-guides/temperature/ it shows a resistor in the drawings. Cant seem to find one in the description

If you're referring to the resistor required for the Temp circuit - it specifies a value of 4.7k. And I believe the data sheet says the value may be between 4.7k and 10k. I have tested and can confirm that the 10k resistor will also work.

 

[Gareth elliott]

I have also been looking at solutions for PH probes. I think the one listed above by @Gareth elliott is actually an analogue output, which would require conversion via ADC (MPC3008?) Gareth elliott, if these are different than the one you have please provide a link to that product.
Here are links to the probe, I think they are the same:
https://www.ebay.com/itm/Liquid-PH0...271985715879?_trksid=p2385738.m4383.l4275.c10
And here is a link to Data Sheet:
http://vi.vipr.ebaydesc.com/ws/eBay...descgauge=1&cspheader=1&oneClk=1&secureDesc=0
The addition of the PH probe is something that I'm willing to experiment with as well, hopefully I can help add to this great project.

Yeah i found the a pi specific build, ordered mcp3008. Total build cost now. $44, bought 4 a/d chips this would be a little lower if i bought just 1.

 

[Ranjib]

https://reef-pi.github.io/build-guides/temperature/ it shows a resistor in the drawings. Cant seem to find one in the description

That’s a mistake from my side, I didn’t get a chance to update that guide. It should include a 4.7k resistor

 

[Ranjib]

So, amazon now has the atlas scientific kit back in stock, and I just ordered one. I’ll keep you all posted about the progress

 

[Ranjib]

I have also been looking at solutions for PH probes. I think the one listed above by @Gareth elliott is actually an analogue output, which would require conversion via ADC (MPC3008?) Gareth elliott, if these are different than the one you have please provide a link to that product.
Here are links to the probe, I think they are the same:
https://www.ebay.com/itm/Liquid-PH0...271985715879?_trksid=p2385738.m4383.l4275.c10
And here is a link to Data Sheet:
http://vi.vipr.ebaydesc.com/ws/eBay...descgauge=1&cspheader=1&oneClk=1&secureDesc=0
The addition of the PH probe is something that I'm willing to experiment with as well, hopefully I can help add to this great project.

Just wanted to share some of my learning with the analog output route. Early in the reef-pi development ( I used to call the project as “reefer” then ) I was primarily thinking of analog output sensors (temperature, water level etc) , mcp3008 support was available in reef-pi code base as well. Initially I tried out various sensor like etape and temperature probes (from cheap digital thermometers), though the circuit worked and I could read the analog values , they would not represent the exact metric we want (like temperature in Fahrenheit) and I had to use some scaling factor to convert the sensor reading to usable metric. This is where things get tricky , the logic of this scaling is not same for all the sensors and in the entire range of values.
Let me know what you find , I can always bring back the mcp3008 code and add support for this probe if it worked out. I definitely like the cheaper price point. This Atlas scientific kit is prohibitively expensive :-(

 

[TMB]

Ranjib, what Atlas sensor did you order? There are several variables for the components that vary in cost. I was thinking about ordering the simple development board and "OEM" circuit to try it out. https://www.atlas-scientific.com/ph.html This would be a much cheaper option to start out testing with.
I think the difference is in the signal shielding, which may or may not be needed for this application. My understanding is that when/if you incorporate more than one of this type sensor into the system, full isolation is needed to keep stray signals from being picked up across sensors. your thoughts?

 

[reelss]

Once set up, how do you access Reef Pi? Do you need to have a computer connected to it, or can you access it via the browser, as long as you are on the same network?

 

[Gareth elliott]

Your ip address:8080
User name reef-pi
Pw reef-pi

Example 155.155.1.155:8080

 

[Ranjib]

Once set up, how do you access Reef Pi? Do you need to have a computer connected to it, or can you access it via the browser, as long as you are on the same network?

You can connect it via browser from any device in the same network (like phone or tablet), I access it from internet (when I am in vacation) using port forwarding

 

[Ryan115]

Your ip address:8080
User name reef-pi
Pw reef-pi

Example 155.155.1.155:8080

It was updated a few releases back, no more :8080
All you will need is the IP address from a computer on the same network.

Port forwarding is next on my list.

 

[Ranjib]

Ranjib, what Atlas sensor did you order. There are several variables for the components that vary in cost. I was thinking about ordering the simple development board and "OEM" circuit to try it out. https://www.atlas-scientific.com/ph.html This would be a much cheaper option to start out testing with.
I think the difference in is the signal shielding, which may or may not be needed for this application. My understanding is that when/if you incorporate more than one of this type sensor into the system, full isolation is needed to keep stray signals from being picked up across sensors. your thoughts?

I have ordered this one: https://www.amazon.com/gp/aw/d/B007...fic+ph+kit&dpPl=1&dpID=41jvE+Ni2+L&ref=plSrch

I was initially thinking of getting the tentacle board (which combines circuit for three probes ), but I realized I won’t need the orp or salinity probe

I have a working code for the atlas scientific ezo board already, last year one of the fellow reefer played with the tentacle shield and he shared then prototype code with me

 

[jcmental]

Would this work with the Reef pi program? I'm not sure what to look for by way of interface's. http://www.ebay.co.uk/itm/PH-Sensor-for-Arduino-/222467535540?_trksid=p2385738.m4383.l4275.c10

also is there or will there be a control for running a calcium reactor with a built in ph probe in the reef pi program?
I used to run a Calcium reactor on my old tank but didn't have any form of monitoring the ph in the unit, I'd get another if the Reef pi could be configured to run one.

 

[Gareth elliott]

Would this work with the Reef pi program? I'm not sure what to look for by way of interface's. http://www.ebay.co.uk/itm/PH-Sensor-for-Arduino-/222467535540?_trksid=p2385738.m4383.l4275.c10

also is there or will there be a control for running a calcium reactor with a built in ph probe in the reef pi program?
I used to run a Calcium reactor on my old tank but didn't have any form of monitoring the ph in the unit, I'd get another if the Reef pi could be configured to run one.

I am testing the accuracy of this type of chip myself. I will post my results once i have them. Currently there is no ph sensor in reef pi, ranjib is still working on adding them. Ranjib is using the atlas scientific chip and probe in his build. From what i understand ph support is still going to be some months away. I personally have little faith in the analog probe, but i have a different use. Constant Monitoring of ph as a tank health parameter. The amount of deviation from standard being important not the actual number.
For my high tech planted aquarium, which is not on reef-pi, i have a similar use for controlling ph. Where i would like a ph reading to turn on and off a co2 solenoid. For this i will await ranjib’s findings to see if i use reef-pi or the pin point ph controller($200). To trust a cheap chinese probe with something as important as co2 impregnation, where a small error in readings equals fish death; i am not there yet lol. Also the cost of my build keeps going up, i expect when i am done i will be roughly 1/2-2/3 cost of the atlas setup; after adding in costs of isolation. For isolation i am leaning towards digital isolators like iso7220adr, if this works will be closer to the 1/2 mark or a little less.

 

[Ranjib]

My atlas scientific kit is on the way. I plan to add the support in reef-pi before May, probably sometime in late February.
I went with the full kit, as I need the calibration solutions for additional checks (the kit with three different solution each with different ph)

 

[jcmental]

Well I made my first power bar today. I used a 6 gang power strip and soldered wires to the Live pin inside the unit, I've also taken a live back to my SSR to use as a jumper to each SSR, I've done it in such a way that the neon light inside the switch will light up when the pi brings on that socket. I can also over ride the SSR to bring that socket on if needed simply by switching the switch on. the only down side to this is if you forget to put the switch in the off position the pi will will have no control over that particular socket.
I've done a crud drawing just to help explain my text.

 

[jcmental]

And the finished product complete with shrink tube.

 

[Ranjib]

And the finished product complete with shrink tube.

Sweet :-)

 

[Ranjib]

Coding updates,
last couple of days, i was working on to get an rpi hardware timer based pwm driver working. Couple of posts earlier I mentioned the recent availability of the 2 hardware timers from rpi, which we can use to generate pwm . What this means for us is as long as we want only two dimmable dc output (like individual doser, kessil controllers etc), we can do it reliably just using raspberry pi zero/3. no need for pca9685 IC. this will bring the cost 10-14$ less, save power, space and circuit complexity.

Anyway... i got the library working: https://github.com/reef-pi/rpi/tree/master/pwm
will be working on to integrating this with reef-pi, while I wait for the ph probe . I have received the jebao pp4 , so I might take the rpi pwm driver based code to power the new doser or wave maker.