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

[Diamond1]

So, I've been looking to replace my controller for my Jebao-DCP 15,000 with something RPI driven and was looking at this as a option for the controller. I was wondering if someone with more hardware chops could take a look at tell me if it'll work.

@rushbattle has made something like this work with dc pumps. Check his thread it might get you going in the right direction.
https://www.reef2reef.com/threads/0-10v-control-of-prop-pumps-for-alternating-gyre.510928/

 

[Ranjib]

@Ranjib and @theatrus - thanks for the driver_ui pointer. I'll update my local repo tonight and tinker.

WRT the ATO controller - since I'm only going to read the 'on/off' from the Tunze to monitor usage, my input will be whatever GPIO has that signal, but the 'equipment' won't exist. I am thinking about having an LED just to give it something to connect to in the 'ATO' tab. Is this a viable option?

You have to write a driver for both of this. For the outlet it will be a hal.OutputDriver and for the tunze ato it will be a hal.InputDriver (checkout reef-pi/hal repo for definition and reef-pi/rpi or reef-pi/drivers for example implementation)

 

[Ranjib]

Finally some parts has arrived...

This is my shopping list
http://www.amazon.de/registry/wishlist/250QZH4E9GUSD

Yay . I’m not sure about the ato sensor , keep us posted on how it goes

 

[dmolavi]

You have to write a driver for both of this. For the outlet it will be a hal.OutputDriver and for the tunze ato it will be a hal.InputDriver (checkout reef-pi/hal repo for definition and reef-pi/rpi or reef-pi/drivers for example implementation)

Dang...Looking at the optical sensor you're using, it looks like it outputs 5V when the water is at the right level, but drops to 0V when the water level drops (and the ATO needs to be triggered). This is the opposite of how I will be using it - I will get 3.3V HIGH when the ATO is running and 0V LOW when it isn't. Argh.

Will this still be able to utilize the ATO usage charts?

 

[theatrus]

Dang...Looking at the optical sensor you're using, it looks like it outputs 5V when the water is at the right level, but drops to 0V when the water level drops (and the ATO needs to be triggered). This is the opposite of how I will be using it - I will get 3.3V HIGH when the ATO is running and 0V LOW when it isn't. Argh.

Will this still be able to utilize the ATO usage charts?

All inputs are reversible in software. Just check the box

 

[dmolavi]

All inputs are reversible in software. Just check the box

Hmmm, so then wouldn't the existing ATO functionality work for me, reverse the input...check if it's high, light the LED (that's a 'dummy' ATO pump in the equipment)?

 

[Ranjib]

Hmmm, so then wouldn't the existing ATO functionality work for me, reverse the input...check if it's high, light the LED (that's a 'dummy' ATO pump in the equipment)?

Yup

 

[dmolavi]

Yup

w00t

can't wait for the gear to arrive.

 

[rushbattle]

@rushbattle has made something like this work with dc pumps. Check his thread it might get you going in the right direction.
https://www.reef2reef.com/threads/0-10v-control-of-prop-pumps-for-alternating-gyre.510928/

Interestingly, while I personally don’t know much about motor controllers, my company builds electric motors and use motor controllers all the time. But ours are huge multikilovolt, 250 kilowatt systems so I am not familiar with the common small DC motor controllers. However, I suspect that one in the link won’t work as it’s expecting a brushed DC motor, while the Jebao is a brushless DC, or in our terms permanent magnet, motor. The RPi pwm pins could definitely send pwm signal to that controller though.

 

[theatrus]

There are two main types of brushless motors: sensored and sensorless (back EMF). A controller for one won’t work for the other, especially a sensored controller for a sensorless motor.

 

[rushbattle]

There are two main types of brushless motors: sensored and sensorless (back EMF). A controller for one won’t work for the other, especially a sensored controller for a sensorless motor.

Thanks for pointing that out, I was thinking that they are all using back EMF in the aquarium pumps. Are there many BLDC motors used in aquarium pumps with Hall effect sensors?

 

[theatrus]

Thanks for pointing that out, I was thinking that they are all using back EMF in the aquarium pumps. Are there many BLDC motors used in aquarium pumps with Hall effect sensors?

IIRC all of the Vortech powerheads are sensored. The larger Vectra pumps are back EMF.

 

[dmolavi]

I can't speak for DC aquarium pumps, but (usually) in power tools (think DeWalt and similar drills, etc) that are DC powered, the motors usually have a Hall effect sensor sensing a diametrically magnetized ring on the shaft of the motor. The sensor sends info back to the controller which compensates with more (or less) power to the motor depending on where the trigger position is (which is usually just a slide pot).

The risk here is that if the user says "take it to 11" (or in our case "pump 1000gph"), the controller will give the motor all the electrons it can...so there needs to be some current limiter in there (fuse, resistor, etc) to prevent overloading. I would see this being an issue in aquarium pumps...water and electricity...esp when the lower cost stuff is taken into account. Just like Harbor Freight, they trim costs by eliminating everything that isn't absolutely necessary for the item to function...

 

[b4tn]

So, an interesting thought I had today. I dabble in Radio controlled cars as one of my other money pit hobbies. The brushless motors are controlled my an electronic speed control that I assume takes a PWM input from the radio receiver. I wonder if there are some pre built ESC that can be interfaced with the pi's PWM?

 

[4dtough]

How do I go about adding additional temperature sensors? I keep getting an error on the one I have setup and I want the redundancy. Last night my tank dropped 3 degrees before the sensor stated working again.

 

[rushbattle]

So, an interesting thought I had today. I dabble in Radio controlled cars as one of my other money pit hobbies. The brushless motors are controlled my an electronic speed control that I assume takes a PWM input from the radio receiver. I wonder if there are some pre built ESC that can be interfaced with the pi's PWM?

The ESC is a motor controller, just built for RC applications.

 

[b4tn]

The ESC is a motor controller, just built for RC applications.

But I am sure there has to be some sort of pre built ESC comparable with pi. It would be pretty easy to control something with the light program via pwm if there was a brushless driver. Just a quick search.

https://www.amazon.com/dp/B075L7YDR9/ref=cm_sw_r_sms_c_api_i_dhtnCbMX999H7

 

[crusso1993]

There are two main types of brushless motors: sensored and sensorless (back EMF). A controller for one won’t work for the other, especially a sensored controller for a sensorless motor.

Thanks for pointing that out, I was thinking that they are all using back EMF in the aquarium pumps. Are there many BLDC motors used in aquarium pumps with Hall effect sensors?

Did someone say, "EMF?"
Sorry, I couldn't stop myself!

 

[theatrus]

I can't speak for DC aquarium pumps, but (usually) in power tools (think DeWalt and similar drills, etc) that are DC powered, the motors usually have a Hall effect sensor sensing a diametrically magnetized ring on the shaft of the motor. The sensor sends info back to the controller which compensates with more (or less) power to the motor depending on where the trigger position is (which is usually just a slide pot).

The risk here is that if the user says "take it to 11" (or in our case "pump 1000gph"), the controller will give the motor all the electrons it can...so there needs to be some current limiter in there (fuse, resistor, etc) to prevent overloading. I would see this being an issue in aquarium pumps...water and electricity...esp when the lower cost stuff is taken into account. Just like Harbor Freight, they trim costs by eliminating everything that isn't absolutely necessary for the item to function...

It’s not used for current limiting - there is a dedicated sense resistor (or using the fet rds) for that. The sensors are for commutation, so the motor controller knows which of the three Wye coils to energize and by how much. Most small motors using a trapezoidal drive scheme and variable PWM to smoothly move. Without any sensor, the speed controller has no idea where the rotor is or how fast it’s going (or if it’s just bouncing back and forth rapidly).

RC ESCs are the same thing at a different scale. Do they use a Hall effect or just back EMF? I haven’t looked at anything RC for a long long time.

 

[dmolavi]

It’s not used for current limiting - there is a dedicated sense resistor (or using the fet rds) for that. The sensors are for commutation, so the motor controller knows which of the three Wye coils to energize and by how much. Most small motors using a trapezoidal drive scheme and variable PWM to smoothly move. Without any sensor, the speed controller has no idea where the rotor is or how fast it’s going (or if it’s just bouncing back and forth rapidly).

RC ESCs are the same thing at a different scale. Do they use a Hall effect or just back EMF? I haven’t looked at anything RC for a long long time.

The hall effect sensors aren't used for current limiting, but they do send info back to the controller saying "the shaft is rotating at X RPM"...the controller then corrects with either more or less power. The current limiting comes into play to make sure that too much power isn't sent...