Backyard Aquaponics
A place to discuss aquaponics

Now this is kind off the topic of the electronics and timers and such but, it is a note we might want to keep in mind.

Ya made a comment here that there is another answer for. Yes in a perfect world one might want the pump to run only long enough to flood the growbed and no longer. However, we are not in a perfect world and most systems are not using a full 2:1 ratio or better. Therefore if you only run the pump long enough to just flood the grow bed each hour, you are probably not circulating/filtering enough of the fish tank water. If it was only about the plants then just pumping enough to flood the beds would be fine, however, filtration/circulation for the fish is very important too. I think this could be a big reason why the 2:1 ratio is a model to aim for. If you only pump long enough to flood the grow beds each hour, then you almost need a 2:1 ratio to get anywhere near filtering the volume of the fish tank each hour.

In short letting the water filter through a flooded bed for a bit longer than needed to flood the bed in order to filter/circulate more of the fish tank water each hour is definitely worth while up to a point.

yes, I would agree, TC. I keep my density fairly low. In fact, my system shuts down at sun down and it starts again in the morning. I'm still in experimentation-mode to try to find a balance between the stock density and amount of electricity the system uses.

Everyone here has very different systems...and there isn't one solution that meets everyone's needs. I'm just trying to come up with a "solution" that could fit many of our needs. I think most of us are simply trying to turn something on or off, whether it's a pump, or a valve, or a sequencer. If I can design a micro based switch, a few software commands could accommodate many of these needs. By all means, I'm no expert with AP....I'm always open to suggestions....even if you say my little controller is useless for everyone here, that's fine. I still learn a little and keep watching my fish grow.

Actually, I think it sounds like a great controller. I think I'm just a bit intimidated by it

If its for a ready to go tested unit and flow switch I think it is much better than reasonable

I like the idea of a flow sensor, I have given some thought to their usefulness, what would the sensor cost on its own? What size pipe are you looking at? You mentioned waterproof how do you wire it up and do the side holes leak?

Would it be possible to put your talents to the design of a water diverter? At the moment my serial GB systems have worked but the inline setup would be more useful if it could be used in a horizontal T diverter instead of vertical then I could more easily keep the piping out of the growbed.

It's actually quite easy to use...or it can be very complicated if it's in host-mode. The stand-alone mode (timer) is very simple to set up:
1) plug unit into USB port. The computer will auto-detect the device and install it as a serial port (usually COM2 or 3)
2) Load up a terminal emulator program such as HyperTerm of PuTTy. Once it's detected, a menu will show up on the terminal screen.
3) Send a couple of commands: "MODE=1" (puts it in timer mode), "A=45" and "B=15" tells it to be off for 45 minutes and on for 15 minutes. you can also hit "?" and it will display a list of commands you can enter in.
4) Unplug from the computer and plug it into your system.

The biggest problem with it is to make any changes, you either have to bring it to your computer, or your computer to it! I'm debating making a little hand-held "remote" that could be used to program it...sort of like a TV remote. If you have a bunch of these in your system, I think it would be easier to program them with one...... I have all kinds of crazy thoughts!

I'm hoping to keep the stand-alone sensor at around $25....ideally $20. It depends how much it costs to laser cut the flapper inside it. That photo is a prototype so there's a lot of slop in it..quite exciting cutting that little piece of plastic with a bandsaw!

There's a collar that goes around the sensor that keeps it from leaking. I just didn't take a pic of that part. It's made out of 1" PVC.

If I understand the horizontal diverter correctly, it may be difficult to design since that would create pressurized system and then have to have seals on all the moving components...? Perhaps you can do a little drawing so we can have a better idea? For serial system (6 beds/1 pump), I made a sequencing valve...It's been running all summer.... http://www.youtube.com/watch?v=u7XGME4kdJc Rupe has one too that can handle larger flow than this one.

I love that valve

Ok here is the latest update to my universal timer.

The circuit has changed slightly I have added an extra link for selecting between controlling a car door actuator by relay or by h-bridge. Its J3 on the circuit.

For those that would like it I am including some circuits that could be used to control a basic relay, or for the car door actuators a sample for controlling via relays.

For those that would like to use a H-Bridge I suggest you use the one detailed here
http://www.mcmanis.com/chuck/robotics/t ... rcuit.html

It is reliable and low cost. Control is via 3 control lines Forward, reverse and enable
the way I have set up the time it will pulse the actuator on forward to open the valve, leaving it open for the on time, while it is on it applies a short across the motor to provide motor braking, which can help hold it in position. Then on close it pulses the reverse line and again applies the brake. On the circuit A is forward B is reverse C is enable.

When actuator control is by relay forward and reverse are controlled by Relay1 and the pulses on A and B pulse Relay2 control the on time.

For general control of a relay instead of actuator D is used as the output.

For costing and parts list examples (based on Futurlec prices)



For Timer

PIC16F630-I/P PIC16F630 Flash 14-pin 1kB Programmed 1 8.00
78L05 78L05 - 5V Positive Regulator (100mA) 1 0.25
LED3YG Yellow-Green 3mm Round LED 1 0.15
C100UMC 0.10uF (100nF) 50V Multilayer Ceramic Capacitor 1 0.08
C330UMC 0.33uF 50V Multilayer Ceramic Capacitor 1 0.25
TACT001 Small Black Tactile Switch 1 0.31
R560R14W 560ohm 1/4W 5% Carbon Film Resistor 2 0.24
R0047K14W 4.7kohm 1/4W 5% Carbon Film Resistor 2 0.24
HEADS10 10 Pin .100 Straight Male Headers 1 1.12
HDSHCB Shorting Block Closed Black 4 0.76
HDCONNS4 4 Pin .100 Header Connector 1 0.19
STPBRD2 Stripboard - Small 1 1.19
Total (AUD) 12.78


For H - Bridge

TIP107 TIP107 - PNP Power Darlington Transistor 2 1.38
TIP102 TIP102 NPN Power Darlington 2 1.88
TLP521-4 TLP521-4 - Quad PhotoCoupler 1 0.75
RN1K5P 1kohm 4 Resistor Network (5 pins) 1 0.22
RN10K5P 10kohm 4 Resistor Network (5 pins) 1 0.22
RN470R5P 470ohm 4 Resistor Network (5pins) 1 0.22
Total (AUD) 4.67

For Actuator relay control

HFD2-12 DPDT 12V 2A PCB Relay 2 2.00
BC549 BC549 Transistor 2 0.24
FR102 FR102 100V 1A Fast Recovery 4 0.48
R470R14W 470ohm 1/4W 5% Carbon Film Resistor 2 0.24
Total (AUD) 2.96

For relay control
GRBLADE Socket for Blade Terminals DPDT (10A) 1 3.69
GR230V10ABL DPDT 230VAC 10A Blade Terminals Relay 1 6.19
BC549 BC549 Transistor 1 0.12
FR102 FR102 100V 1A Fast Recovery 1 0.12
R470R14W 470ohm 1/4W 5% Carbon Film Resistor 1 0.12
Total (AUD) 10.24
or cheaper if lower power relay is chosen.

To test it and demonstrate how to program it I have done a rough prototype from parts I had.
Here is a video of how easy it is to program
http://www.youtube.com/watch?v=rrMbNX7JfcE

and an example strip board layout, this has not been tested so please check before powering up as might have slipped up in the layout.

And finally how the links are configured for the various modes.

Nice job on the one-button programming. How do you like working with the PIC's? I've only have done programming on the AVR's......

What were you programming it to do on the video? Its very much like getting fault codes out of an ECM.

Here is the description from youtube
The unit can be programmed to have independent on and off times from 1 sec to 99 min & 99 seconds.
When the timer is powered up a led flashes for four seconds to allow you to enter programming mode.
If you press the switch the unit will enter programming mode and both leds will light.
programming is done in 10 steps
1 = on 10's of seconds
2 = on 1's of seconds
3 = on 10's of minutes
4 = on 1's of minute
5 = off 10's of seconds
6 = off 1's of seconds
7 = off 10's of minutes
8 = off 1's of minutes
9 = 10's 0f pulse duration
10 = 1's of pulse duration

With each step in the programming the count starts at 0 and progresses to 9, if you do nothing then zero is set, if you press the button it accepts the number it is on at the time. The example shows the programming set to
1 = 0
2 = 3
3 = 0
4 = 0
5 = 0
6 = 3
7 = 0
8 = 0
9 = 5
10 = 0
which is on time 3 seconds, off time 3 seconds, pulse duration 50 (which is actually multiplied by 5ms so its 250 ms)

Pulse duration is used to control car door actuators used as flow vales.