Jebao doser.

[AbjectMaelstroM]

Just did some testing with a cheapo dosing pump like this.

https://alexnld.com/wp-content/uploads/2015/03/61650.jpg

I think the controller DC ports are the basically the same as the ML adapter. That has darlington pairs which is two BJT's working together, I think the end result is the same. If you look at Design #1 on this page you'll see how controller DC ports are setup, the PWM from pca9685 controls the mosfet though.

5 Simple DC Motor Speed Controller Circuits Explained

The article presents 3 types of DC motor speed controller circuits using a simple mosfet and potentiometer, next using a IC 555 and then with IC 556

www.homemade-circuits.com

At full speed (12v) changing the pca9685 frequency from 50 - 1000 has no visual or audio affect.

With freq set to 1000 the speed can be turned down to 47 which was 5.8v, the pump was running ok, left for 5 minutes no heat.

With freq set to 50 the speed could go down to 28 but that resulted in the same 5.8v. I think I could hear I high pitched squeal but barely.

If I went lower in speed (voltage) the pump would run but not enough juice to start up. So 6v for a 12v pump, sounds good.

Then I tried a 12v LED strip light with similar results but could see more effect with frequency changes.

At 1000hz, speed 1 it was 6.67v so light was quiet bright.

At 50hz, speed 1 it was 2.4v but light was flickering quite badly.

Finally settled at 60hz and it's 2.6v no visual flicker but I'm sure it's there and light is very dim.

Good stuff right there! I'll keep this in my back pocket. I did notice that when I lowered frequency to 100 from 800 the pump became more audible. I

Also this makes me want to use a DC port to power my sump light LED strip, pretty sure it's a 12v; rather than powering it from the wall.

 

[ReeferLou]

Good stuff right there! I'll keep this in my back pocket. I did notice that when I lowered frequency to 100 from 800 the pump became more audible. I

Also this makes me want to use a DC port to power my sump light LED strip, pretty sure it's a 12v; rather than powering it from the wall.

Just make sure it draws less than 500ma - that's all the ULN2803 output is rated for. If you need more consider a L293D driver board.

 

[robsworld78]

Good stuff right there! I'll keep this in my back pocket. I did notice that when I lowered frequency to 100 from 800 the pump became more audible. I

Also this makes me want to use a DC port to power my sump light LED strip, pretty sure it's a 12v; rather than powering it from the wall.

I'm not really sure what the best frequency is to use, I get the same with a lower frequency. Strip lights work good on them, if they're RGB you can connect each color to different port for independent control. You can also add any switch to a sensor port so the light comes on when you open the door.

 

[AbjectMaelstroM]

I'm not really sure what the best frequency is to use, I get the same with a lower frequency. Strip lights work good on them, if they're RGB you can connect each color to different port for independent control. You can also add any switch to a sensor port so the light comes on when you open the door.

Yeah it's just a single color (white) led strip. I have it going through a micro pressure switch on the door so it comes on when the door is open. Plug realestate is valuable so Im always on a lookout for a way to free-up a plug.

 

[ReeferLou]

So I got my Jebao 4S hooked up to my reef pi using an L293 driver board.

I use a typical RJ/phone jack with 6 poles and it plugs directly into the doser. The doser does come with the cable too.

With speed of 48 and time of 10 secs I can get 5ml output. I dilute my Alk/Calc with RODI water so 10ml (20sec) target is good enough for me. I use an empty water bottle with a hole drilled into the cap for the reservoir - nothing fancy.

Note that I reversed the polarity of the power to where I supply +12 to the motor with the ground on pins 1+6. It was just my preference BUT I find the LED lights on the doser would not work. This bothered me so even with no functional issue I de-soldered the LED on the unit to reverse LED pinout and now it is fine - but just wanted to point that out for others. It was not very hard to do.

 

[ariellemermaid]

Sounds good. Yeah I'm using RoboTank with Michael Lanes Jebao slave doser adapter.

https://www.tindie.com/products/ranthalion/dosing-pump-adapter/

Using PWM signal from the PCA9685 to the adapter which is then talks to the doser. After opening the doser up, I don't think it has any "controller" components in it, just routing power and is relying on the reefpi/adapter.

I’m getting the DP4 and thinking about reef pi and robo tank to try and control it. Can you explain to me exactly what this control board does? In other words, why can’t you just wire 4 DC output ports on the Robo Tank directly to each of the 4 motors? Does it modulate the current or something? Also, what port(s) on the Robo Tank are you connecting to this controller board? Thanks!

 

[ReeferLou]

I’m getting the DP4 and thinking about reef pi and robo tank to try and control it. Can you explain to me exactly what this control board does? In other words, why can’t you just wire 4 DC output ports on the Robo Tank directly to each of the 4 motors? Does it modulate the current or something? Also, what port(s) on the Robo Tank are you connecting to this controller board? Thanks!

The control board acts like a solid state relay that can PWM. If you do not PWM then the output of the pumps will be like 1ml / sec - so yes you can connect the pumps to straight 12v as I did . You will not be able to tightly control the output as with the PWM.

 

[ariellemermaid]

The control board acts like a solid state relay that can PWM. If you do not PWM then the output of the pumps will be like 1ml / sec - so yes you can connect the pumps to straight 12v as I did . You will not be able to tightly control the output as with the PWM.

Oh! I didn’t get that from reading the Robo Tank manual at all! The manual makes it sound like controlling as on/off or PWM is determined by whether it’s added as an “output” or “Jack” in reef pi. So what you’re saying is that anything you want to control by PWM requires a separate 12v PWM controller? So one for the dosing pump, one for an LED light strip, one for everything? That’s a lot of extra controllers!

Would I need a separate PWM controller for each pump? If not, how does reef pi communicate with each pump individually through 1 controller? Just when I thought I was starting to understand things..... I’m trying to connect the pumps directly because I bought the DP4, not the S with the slave port.

 

[ReeferLou]

Oh! I didn’t get that from reading the Robo Tank manual at all! The manual makes it sound like controlling as on/off or PWM is determined by whether it’s added as an “output” or “Jack” in reef pi. So what you’re saying is that anything you want to control by PWM requires a separate 12v PWM controller? So one for the dosing pump, one for an LED light strip, one for everything? That’s a lot of extra controllers!

Would I need a separate PWM controller for each pump? If not, how does reef pi communicate with each pump individually through 1 controller? Just when I thought I was starting to understand things..... I’m trying to connect the pumps directly because I bought the DP4, not the S with the slave port.

I was referring to the Tindie control board. I hooked up 2 of my doser pumps to a regular OUTPUT with NO PWM and the 2 "built in" reef-pi PWM to the other 2 inputs on the tindie board. I was not using robo-tank board. I was just trying to say you do not need PWM for pumps but they will pump faster at 1ml/sec. And yes they need to be 12V outputs. Since you have the regular DP4 I am not sure if you want to bypass the controls on that and use the Robo-tank. That may require more modifications. There is a way to get more than 2 PWM using the PC9685 expander board, this may be included in the robo tank design.

 

[robsworld78]

The DC ports

I’m getting the DP4 and thinking about reef pi and robo tank to try and control it. Can you explain to me exactly what this control board does? In other words, why can’t you just wire 4 DC output ports on the Robo Tank directly to each of the 4 motors? Does it modulate the current or something? Also, what port(s) on the Robo Tank are you connecting to this controller board? Thanks!

The DC ports are PWM controlled, the level of the PWM signal determines how much voltage comes out the DC port. You can get a range from about 2.5v - 12v however most motors don't appreciate anything under 6v. Some motors are strictly 12v so you wouldn't want to slow it down, you can usually tell how the motor sounds if it's ok.

Because the ports are PWM driven you can assign them as "outlets" or "jacks" in reef-pi so you can use them for anything. The controller has 8 DC ports total, 7 are high powered and the feed port is low power, anything under 300ma.

As @ReeferLou mentioned it's probably more difficult to connect DP4 as it has it's own controller built in, the S is a straight connection to the motors I believe. If you went down this path you probably need to disconnect wires going to motors and wire direct.

 

[ariellemermaid]

The DC ports

The DC ports are PWM controlled, the level of the PWM signal determines how much voltage comes out the DC port. You can get a range from about 2.5v - 12v however most motors don't appreciate anything under 6v. Some motors are strictly 12v so you wouldn't want to slow it down, you can usually tell how the motor sounds if it's ok.

Because the ports are PWM driven you can assign them as "outlets" or "jacks" in reef-pi so you can use them for anything. The controller has 8 DC ports total, 7 are high powered and the feed port is low power, anything under 300ma.

As @ReeferLou mentioned it's probably more difficult to connect DP4 as it has it's own controller built in, the S is a straight connection to the motors I believe. If you went down this path you probably need to disconnect wires going to motors and wire direct.

Thanks for the reply and the email! Even though people have worked with the DP4 I’m finding it difficult to find straight how-to info for the reef pi because people are working with all different kinds of hardware (Robo Tank vs. no Robo Tank, DP4 vs. DP4-S).

Since the regular DP4 is the one I could easily get on Amazon with free shipping, that’s the one I went with before I had thoughts of controlling with reef pi. Wiring the motors directly I would consider a pretty small modification compared to what some folks are doing. The DP4 is such a great deal at $55 compared to almost any other 4 pump dosing option and even a DIY solution where you’d have to come up with some kind of housing. Heck the Apex 2-pump is $300!

I think this is good info on the Robo Tank from Rob’s email so I wanted to post it here for everyone:

“The controller has a pca9685 16 channel 0-5v PWM driver, 8 channels are used for the DC ports, the feeder port is technically the same so that’s one of them although a feeder only needs on/off. This allows you to add any of the 16 channels in reef-pi as either “outlets” or “jacks” for either on/off or speed controlled. The ports run in a range of about 2.5v – 12v.”

Overall, it seems to me like the Robo Tank is the go-to solution for novices and weekend programmers to get into reef pi without having to engineer separate controllers and circuits. Or anyone looking for a clean all-in-one reef pi design. I already have an unused Pi 3, so I’m looking at approx $200 to get more functionality than the Apex EL at $500. Well done!

 

[robsworld78]

Thanks for the reply and the email! Even though people have worked with the DP4 I’m finding it difficult to find straight how-to info for the reef pi because people are working with all different kinds of hardware (Robo Tank vs. no Robo Tank, DP4 vs. DP4-S).

Since the regular DP4 is the one I could easily get on Amazon with free shipping, that’s the one I went with before I had thoughts of controlling with reef pi. Wiring the motors directly I would consider a pretty small modification compared to what some folks are doing. The DP4 is such a great deal at $55 compared to almost any other 4 pump dosing option and even a DIY solution where you’d have to come up with some kind of housing. Heck the Apex 2-pump is $300!

I think this is good info on the Robo Tank from Rob’s email so I wanted to post it here for everyone:

“The controller has a pca9685 16 channel 0-5v PWM driver, 8 channels are used for the DC ports, the feeder port is technically the same so that’s one of them although a feeder only needs on/off. This allows you to add any of the 16 channels in reef-pi as either “outlets” or “jacks” for either on/off or speed controlled. The ports run in a range of about 2.5v – 12v.”

Overall, it seems to me like the Robo Tank is the go-to solution for novices and weekend programmers to get into reef pi without having to engineer separate controllers and circuits. Or anyone looking for a clean all-in-one reef pi design. I already have an unused Pi 3, so I’m looking at approx $200 to get more functionality than the Apex EL at $500. Well done!

Thanks, it sounds like the DP4 has extra brains for DP4-S. The easiest thing is to just disconnect the wires from motors and run new wires to controller, this way you can undo easy too.