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

[geekengineer]

So is there a thread on the pressure transducer idea? I also go look but just checking in case it doesn't' exist yet. I would be interested in something that could measure level say in something bigger like a 55gal drum for saltwater storage.

 

[dmolavi]

So is there a thread on the pressure transducer idea? I also go look but just checking in case it doesn't' exist yet. I would be interested in something that could measure level say in something bigger like a 55gal drum for saltwater storage.

On the pico board thread, @theatrus has a 3D render of a board he's been designing for it. The major blocker right now is the lack of USB support in reef-pi, as it uses a USB interface back to the Pi.

 

[Bigtrout]

Theres an i2c water pressure sensor, thats not specced too bad, thing is the board part has to be waterproofed, it returns an analog voltage

MS5837 .2mm accuracy

 

[theatrus]

On the pico board thread, @theatrus has a 3D render of a board he's been designing for it. The major blocker right now is the lack of USB support in reef-pi, as it uses a USB interface back to the Pi.

Not sure its the major blocker, as I could adapt this to an ADS1115 breakout as well. Its a 0-5V analog output differential pressure sensor.

 

[KevinDodge]

A while ago I was playing around with using capacitance as a way to measure fluid height. I stuck 2 strips of aluminum tape on either side of a cup and then used my multimeter to to measure the capacitance. As I would add/remove water it would increase/decrease capacitance accordingly. I have wanted to do more experimentation with this to see if it would be consistent over time but I needed a device with an analog pin to be able to do the capacitance check. Has anyone else tried this?

Here is the instructable I was following. https://www.instructables.com/id/Capacitive-Fluid-Level-Sensor/

 

[geekengineer]

A while ago I was playing around with using capacitance as a way to measure fluid height. I stuck 2 strips of aluminum tape on either side of a cup and then used my multimeter to to measure the capacitance. As I would add/remove water it would increase/decrease capacitance accordingly. I have wanted to do more experimentation with this to see if it would be consistent over time but I needed a device with an analog pin to be able to do the capacitance check. Has anyone else tried this?

Here is the indestructible I was following. https://www.instructables.com/id/Capacitive-Fluid-Level-Sensor/

Interesting I haven't tried that. So i can't quite tell if the metal parts isolated from the water? Hopefully that would be the case. Maybe we need a separate thread on water level sensors. lol Is there one around already?

 

[Bigtrout]

Something to keep in mind, when thinking about water level sensors. KISS is the rule here. Most industrial controls dealing with fluid levels, are designed such that while there may be several sensors in a control to get fluid levels( pressure sensors, infrared, ultrasonic etc) the failsafes to back those up are generally simple mechanical float switches.

That being said, I think for reef pi we need to be looking in the direction of relatively simple sensors for water level. I agree with @theatrus here, the most robust sensors with relatively easy support for the developers are :
1. Mechanical floats
2. Pressure sensors(including a differential pressure type sensor)
3. The E-tape type sensors

These also happen to be the easiest for someone building a reef pi for the first time to implement into their setup.

 

[Hookster15]

Can I put a 7 inch display on a PI zero using HDMI ?, should i just keep the PI 3 in line?

 

[Mikeneedsahobby]

Can I put a 7 inch display on a PI zero using HDMI ?, should i just keep the PI 3 in line?

I connected a 5 inch to a pi zero. It worked but the web browser in raspbian runs very slow on a pi zero. Combined with a small screen and fat fingers I found the setup not worth it. I removed my screen and only use my laptop and or phone to see reef-pi now.

 

[doughboy]

Agree on the ultrasonic. The absolute accuracy is meh, and in an enclosed small space will hear tons of reflections. E-tape or a pressure transducer is the way to handle analog level.

I've used it for years with no accuracy issue. The software use a running average to calculate the reading. The ping is in milliseconds, so will not affect any animals.

 

[pickupman66]

Just wanted to say thanks to those that helped get be back on track here. it is nice to see everything working as it should and the trends showing up. Amazing how much my heater actually runs.

 

[Hookster15]

I connected a 5 inch to a pi zero. It worked but the web browser in raspbian runs very slow on a pi zero. Combined with a small screen and fat fingers I found the setup not worth it. I removed my screen and only use my laptop and or phone to see reef-pi now.

Thanks, its a thought.

 

[KevinDodge]

I thought I would mention that on this page -- https://reef-pi.github.io/guides/intro/ -- The "Dosing Controller" link is wrong. I put a PR in github to change it but I am not sure anyone monitors that github account.

Also on this page -- https://learn.adafruit.com/reef-pi-guide-5-dosing-controller/circuit-construction -- The fritzing diagram is slightly wrong. In the top middle the yellow wire is connected to the wrong line. The line it shows it shows is ground. It should moved one pin to the right. The pictures of the actual board are correct.

 

[dmolavi]

Sooo I did some looking. The company that manufactures ETape is less than 3 miles from my house haha. I might have to go visit.

 

[theatrus]

I've used it for years with no accuracy issue. The software use a running average to calculate the reading. The ping is in milliseconds, so will not affect any animals.

Interesting! I assume you use this on a sump? Also interested in any pics of your controller setup.

 

[16Reefer170]

Hi all, I wanted to mention that adafruit.io has a very nice “notification” setting in the feed section. It will notify by e-mail if the reef-pi data feed (in my case temp) does not arrive as expected. My temp is updated every 2 min, and I have Adafruit set to notify me if goes more than 10 min without an update. It’s nice to know that my network, power, and reef-pi are all up and running.

 

[buddy.]

So I am having a couple of problems that hopefully I can sort out.

Firstly, my temperature sensors drop out randomly. Today they randomly dropped out while I was not home and the heater got stuck on and my tank got to 102F.
It also failed to send an alert (alerts had been working previously)
I use a titanium heater that usually runs from its own controller but I decided to try reef-pi t control it.
If I power off my reef-pi and turn it back on, all the sensors are working again.

The other problem is that my metal halide does not turn off when I shut the relay off in the equipment tab. I tried other equipment on that outlet and it works perfectly, just seems the MH gets stuck on.

 

[4dtough]

you have a reef-pi build ? or its related to something else, just curious

Reef pi build, I've been meaning to set up a build thread but haven't got to it yet, maybe this weekend.

 

[Bigtrout]

So I am having a couple of problems that hopefully I can sort out.

Firstly, my temperature sensors drop out randomly. Today they randomly dropped out while I was not home and the heater got stuck on and my tank got to 102F.
It also failed to send an alert (alerts had been working previously)
I use a titanium heater that usually runs from its own controller but I decided to try reef-pi t control it.
If I power off my reef-pi and turn it back on, all the sensors are working again.

The other problem is that my metal halide does not turn off when I shut the relay off in the equipment tab. I tried other equipment on that outlet and it works perfectly, just seems the MH gets stuck on.

How much draw does the MH light have in amps?
What are your relays rated at?

I ask because a metal halide ballast is a highly inductive load. When power is cut quickly on a highly inductive load, a voltage spike is produced that can damage a relay contacts.
To combat this, an RC network or MOV can be connected across the load to limit this spike.
With inductive loads, its better to oversize the relays and use some type of protection.

 

[Bigtrout]

So I am having a couple of problems that hopefully I can sort out.

Firstly, my temperature sensors drop out randomly. Today they randomly dropped out while I was not home and the heater got stuck on and my tank got to 102F.
It also failed to send an alert (alerts had been working previously)
I use a titanium heater that usually runs from its own controller but I decided to try reef-pi t control it.
If I power off my reef-pi and turn it back on, all the sensors are working again.

The other problem is that my metal halide does not turn off when I shut the relay off in the equipment tab. I tried other equipment on that outlet and it works perfectly, just seems the MH gets stuck on.

In respect to your temp sensors, how are they wired...have you checked all connections? How long are the cables and how many sensors? What size resistor did you use as a pull up resistor?
Try disconnecting the sensors one at a time to see if one sensor may be causing the problem. Troubleshoot further from there.