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

[AquaRaider44]

Alright running into a question as I am looking at what parts to buy for the dosing, lighting, and pH. I want to run all of these on one Pi. I see that the pH monitor build uses the same SDA / SCL pins (GPIO 2&3) as the PCA9685 uses. What is the best way to wire up all of these? Should the pH and PCA 9685 both be connected to the SDA / SCL pins (GPIO 2&3) or should the pH be connected to the PCA 9685 which is then connected to the SDA / SCL pins (GPIO 2&3)? Thanks for your help!

 

[Ryan115]

Alright running into a question as I am looking at what parts to buy for the dosing, lighting, and pH. I want to run all of these on one Pi. I see that the pH monitor build uses the same SDA / SCL pins (GPIO 2&3) as the PCA9685 uses. What is the best way to wire up all of these? Should the pH and PCA 9685 both be connected to the SDA / SCL pins (GPIO 2&3) or should the pH be connected to the PCA 9685 which is then connected to the SDA / SCL pins (GPIO 2&3)? Thanks for your help!

Whichever way works out better for your connections. You can have up to 128 devices on a single i2c bus.
As you add more than one device on i2c, just keep an eye on the pull up resistors on each device. Ideally you will need to remove/jumper on all but one of the devices.
Actually I think the raspberry pi has internal pull ups on the i2c, so you may be able to remove them from all devices. @Ranjib are these set in hardware on the board, or do we have to call them in software?

All that being said, I have not removed them from my devices (and most people probably havent either) and I have not had an issue. But I am only running a single PCA9685 on the i2c bus.

 

[b4tn]

Had my first reef-pi failure today. More specifically the power strip. Reef-pi is actually working perfectly. I got txt bombed that my temp was below the threshold this morning. Luckily over the course of my 8 hour work day my temp only dropped a few degrees from 78.5 to 75 before I got home. At lunch I picked up a new heater since my eheim is 4 years old anyway and honestly I thought it failed. Turns out my heater outlet is not working. I put it on on my spare outlet and all is good now. What’s funny is I can hear the heater relay click on and off. I need to break into the power box and take a closer look

 

[b4tn]

I just confirmed the relay for the heater outlet failed. All the other relays work just fine. To be honest it does not surprise me and I kind of expected it since I am using reefpi to control the heater. I am going to go ahead and trim my heater up and let it control the switching for now and leave it on the spare outlet until I can replace the relay board. But this may be my excuse to change the heater relay to solid state. Just for everyone’s info these are the relays I got.

https://www.amazon.com/dp/B00LW2GA5Y/ref=cm_sw_r_sms_c_api_i_wDJYCbTDFGBS4

The heater relay lasted about 3 months switching on and off all day. My interval is set to 60 seconds

 

[Bigtrout]

I just confirmed the relay for the heater outlet failed. All the other relays work just fine. To be honest it does not surprise me and I kind of expected it since I am using reefpi to control the heater. I am going to go ahead and trim my heater up and let it control the switching for now and leave it on the spare outlet until I can replace the relay board. But this may be my excuse to change the heater relay to solid state. Just for everyone’s info these are the relays I got.

https://www.amazon.com/dp/B00LW2GA5Y/ref=cm_sw_r_sms_c_api_i_wDJYCbTDFGBS4

The heater relay lasted about 3 months switching on and off all day. My interval is set to 60 seconds

What wattage was the heater on the relay

 

[b4tn]

What wattage was the heater on the relay

It was a 250watt eheim beaver

 

[AquaRaider44]

It was a 250watt eheim beaver

Did u have it default open or closed?

 

[b4tn]

Did u have it default open or closed?

For the heater is was default open. So if reefpi lost connection or power the heater would turn off.

 

[AquaRaider44]

Normally closed would have prevented the tank from going too cold as relay would fail closed and heater would continue to function based off it's own temp sensor

 

[b4tn]

Normally closed would have prevented the tank from going too cold as relay would fail closed and heater would continue to function based off it's own temp sensor

It’s kind of a toss up which way to wire it. I did it NO so that the heater would stay on if I disconnect reefpi. But then there is it not heating the tank if the relay fails. I will have to re think my relay set up.

 

[sergifed91]

I'm going the pi route. If I'm going to be automating my skimmer, circulation pumps, heater and sbreef lights how many pi's do I need to do this?

 

[Bigtrout]

It was a 250watt eheim beaver

So the heater drew 2.1 amps give or take and those relays are rated for 10 amps resistive load...this is what scares me about the 8 to 10 dollar relay boards...which I am changing in my build to a name brand industrial relays.
I have solid state controlled heaters(aquaeon pro) but I run mine normally closed so that the heater does the control and reef pi is the failsafe.
You have the relays working the heater which has them clicking on and off more often. But according to the songle relay specs (blue relays used on all these relay boards)they should be good for at least 100,000 operations at 2 amps.
Do the math:
100,000 divided by 1440 minutes in a day =only 70 days if the heater switches on and off every minute.

You get what you pay for and I cant trust my tank to hinge on a few .35 cent relays.
A similar rated mini industrial name brand relay like an idec, phoenix contact, allen bradley is rated for a few orders more magnitude of operational life. The phoenix contact relays I will be using are rated at 20,000,000 operations at 2 amps. Of course they cost more, but my main goal for reef pi is functionality and RELIABILITY. Being an electrician and cnc service engineer, I cant bring myself to trust 35 cent relays for something as critical as heaters.
That being said, 100,000 operations is a good long life for something that switches on and off only a few times a day.

 

[Ranjib]

Whichever way works out better for your connections. You can have up to 128 devices on a single i2c bus.
As you add more than one device on i2c, just keep an eye on the pull up resistors on each device. Ideally you will need to remove/jumper on all but one of the devices.
Actually I think the raspberry pi has internal pull ups on the i2c, so you may be able to remove them from all devices. @Ranjib are these set in hardware on the board, or do we have to call them in software?

All that being said, I have not removed them from my devices (and most people probably havent either) and I have not had an issue. But I am only running a single PCA9685 on the i2c bus.

All on hardware . We don’t configure any pull up or down resistor from software

 

[Ranjib]

I just confirmed the relay for the heater outlet failed. All the other relays work just fine. To be honest it does not surprise me and I kind of expected it since I am using reefpi to control the heater. I am going to go ahead and trim my heater up and let it control the switching for now and leave it on the spare outlet until I can replace the relay board. But this may be my excuse to change the heater relay to solid state. Just for everyone’s info these are the relays I got.

https://www.amazon.com/dp/B00LW2GA5Y/ref=cm_sw_r_sms_c_api_i_wDJYCbTDFGBS4

The heater relay lasted about 3 months switching on and off all day. My interval is set to 60 seconds

This is very informative. Thank you for sharing. What was the heater rating ? Like in wattage

 

[Ranjib]

This is very informative. Thank you for sharing. What was the heater rating ? Like in wattage

Oops , sorry I noticed you answered this already.

 

[Zippyfear]

I'm going the pi route. If I'm going to be automating my skimmer, circulation pumps, heater and sbreef lights how many pi's do I need to do this?

It’s kind of a toss up which way to wire it. I did it NO so that the heater would stay on if I disconnect reefpi. But then there is it not heating the tank if the relay fails. I will have to re think my relay set up.

After reading this, I think my strategy will be a primary heater with the built in thermostat, with the system to turn it off if the tank temp crosses above 81 degrees, and a secondary heater switched off, only to switch on(controlled) to provide additional heat below 80.. as of today, both heaters were running with their built in thermostat and all 3 probes have run between 80.6 and 80.8 all day.

What's everyone else doing to maintain temp? and what temp ranges do you keep?

 

[Bigtrout]

I'm going the pi route. If I'm going to be automating my skimmer, circulation pumps, heater and sbreef lights how many pi's do I need to do this?

Depends on how many channels of lighting and how many outlets. A typical reef pi setup with one pi following the guides can handle 8 power outlets and 16 pwm channels for lighting and ato. Adding a second uln 2803 will get you 4 additional outlets and leave a few gpio for inlets.

But I think a new feature being added to 3.0 is being able to control a cluster of reef pi with one main reef pi, which would give you alot of expansion room.

 

[Bigtrout]

After reading this, I think my strategy will be a primary heater with the built in thermostat, with the system to turn it off if the tank temp crosses above 81 degrees, and a secondary heater switched off, only to switch on(controlled) to provide additional heat below 80.. as of today, both heaters were running with their built in thermostat and all 3 probes have run between 80.6 and 80.8 all day.

What's everyone else doing to maintain temp? and what temp ranges do you keep?

I use my heaters set at 78 with their own thermostats, to maintain 78 degrees. I have 2 heaters at 250w in a 75 gallon freshwater planted tank. If one heater tstat fails in off position, the second can handle the tank. Reef pi is set up so that each heater has its own control. They are wired NC and set at 80. If my heater tstat sticks ON, the tank gets to 80 and reef pi opens the circuit to prevent boiled fish. If reef pi fails, the heaters still run on their own thermostat thru the NC relays.
Can you tell i have had a few failed heater deaths? I like redundancy with the heaters!!

Speaking about redundancy, my reef pi setup on my heaters has been reliable enough that im giving my inkbird controller , that i used to use as a failsafe,to a young neighbor whos just starting into the hobby with a 30 gallon freshwater. With my plant jungle that I cull every 2 weeks he will have a good start on a planted tank with the plants I thin from my tank.

 

[sergifed91]

Depends on how many channels of lighting and how many outlets. A typical reef pi setup with one pi following the guides can handle 8 power outlets and 16 pwm channels for lighting and ato. Adding a second uln 2803 will get you 4 additional outlets and leave a few gpio for inlets.

But I think a new feature being added to 3.0 is being able to control a cluster of reef pi with one main reef pi, which would give you alot of expansion room.[/QUOTE
I'll be running 2 wave pumps, each li light has blues and LEDs whites. 2 sbreefs lights. A heater, and a skimmer. I thought my hob filter but I think that will remain plugged in to my wall outlet. Since that is just house cheeto only. Total of 8 outlets. But will add a ph gauge and eventually a tampeture. Maybe monitor par down the road. But for now 2 wave makers, skimmer and 2 sbreef lights. With 2 c hffanneks one for blues and one for whites.

 

[Bigtrout]

One reef pi should do all you ask, with the exception of reading PAR...thats not a feature on the radar as far as i know.

If you are good with soldering, the adafruit guide is a great project. If not, or you want a good shortcut read up on the fantastic reef pi hats that were designed by a few on here. @Michael Lane @wykat and @theatrus all make a great hat, though there are different features to each, depending on what you want to do.