View Full Version : DIY controller input

05/19/2005, 02:54 PM
I am pretty much finished with my controller and will be ordering PCB's in the next week or so. I want to gage interest in actually selling this as a DIY project. Kind of like a HeathKit approach with shematics and source code for the controller and PCB side of the software. This way everyone can either use the standard Kernel or modify it to fit their needs. I built this to fit my needs and with the components I have to make it as cheap as possible and speed the development time. I have been running the proto-type for about two months while I debug the system.

Here is what I have made so far.

The unit is 68hc11F1 based with a Real Time clock and 32K of NV ram and 64 of PROM. PC communication is standard RS-422 multidrop(small converter hangs of the PC RS-232 port)

Firmware is written in C.

There are four connectors that supply 7 open collector outputs for use with relays or outlet strips. I have also made an outlet strip that is optocoupled with high current triacs for outlet switching. You can really design your own strip depending upon what you need. These outlet strips are hardwires however then can be remote to about 20 feet as long as you can run a wire similiar to CAT-5.

There is one connector that supplies four level switches(contact closures) as well as 4 open collector outputs.

Two RTD temp probes.

two 12-bit DA(0-5V) outputs.

Four BNC probe inputs that can be configured for PH/ORP/ect. All these circuits are similar and can use the same types of circuits with different components. All of these connect to the HC11 via a 12 bit ADC.

Current firmware

There is calibration and temp compensation for three PH probes and a direct reading of ORP. There is not much need for ORP calibration since it is a direct MV reading. I have not played with any other probes however I doube it will be too hard.

There is Calibration routines for both Temp probes.

All outputs are programmed via Time on and Time off. These are also linked to one of the Temp probes so you can turn on heaters, fans and then start turning off lights when certain temp thresholds are reached. Again this is really user defined and the user can modify the firmware himself to meet these needs.

I am currently working on a dosing system that uses positive displacement pumps. so far works great just a little noisy. Not sure how well they will hold up though. resolution is 20 microliters per click. Need more click them more.

All of this can run standalone however I also wrote a Host program that connects to the controller and monitors all the probes/temps/outputs and inputs. These can all be saved to a ASCII file and graphed. All of the time and setpoints can be viewed and modified via the PC. Since the controller is RS-422 it can communicate with multiple controllers with the same program.

Looking for input here from people wanting to make a DIY controller. For those of you that would rather just buy something that done we can do that as well.

Looking for input and I am not trying to step on anyones toes.


05/19/2005, 03:01 PM
Any pics? I am interestein in it.

05/19/2005, 03:53 PM
I have a pic of the prototype however the finished product is alot different and more modular. As soon as my boxes come back I will through one together and take some pics. I can take a picture of the PCB but that is not going to tell you much. In about a week I will have pics and software screen shots posted on a webpage.


05/19/2005, 05:46 PM
Thats cool keep us informed

05/19/2005, 09:27 PM
Sounds very interesting...

I was looking at the Aqua Controllers.. But at the moment they are out of my price range...

Any idea on what kind of a price you are looking at for a finished product and a kit....

And I am assuming a finished product or kit will not include certain things.. IE. Probes, etc...

If I am reading your post correctly.

You have the unit hooked to a PC via Serial port..

Any way of doing this via USB port.... Just curious....

With your prototype... If someone wants to modify the time lights come on and off.. Do they need to know how to program in C or ???

05/20/2005, 05:10 AM
Yes the controller does attach to the computer via RS232 port though a RS422 converter. You can do the same thing with USB. I am running mine now via a USB to 422 converter. The reason I went with 422 is so I can talk to multiple controllers via the same communication line.

The basic kernel does just that turns on outputs(lights) based on time and temp thresholds. Unless you want to do something outside of what the kernel already does there is no need to prgram anything.

PM me with what you want and I will tell you what it will cost in parts assuming that is the way you want to go.


06/08/2005, 12:09 AM

06/08/2005, 06:21 AM
The alpha system has been running for over two months. The PCB for the beta system has been milled and stuffed however I do not have it in a box yet. I have been a little side tracked with my dosing pumps routines. Rather simple however there needs to be a little more fail safe protection in it.

The beta board might be up and running over the weekend. There is not much difference between the alpha board and the beta board other than everything is now on one PCB.

The guy that is making my web page should have it up and running any day now.

06/29/2005, 04:33 AM
For those that expressed interest in this project I finalized the PCB and had it order today. Should be running with the final unit in about two weeks.

07/09/2005, 05:04 PM
how's it commin along?

07/09/2005, 05:42 PM
I get the production board wednesday of this week. I am hoping to switch my system over from the proto-type system to the production one next weekend. All the basic stuff is written and debugged. I am now adding stuff for auto-water change and dimming ballast such as the icecaps.

I think I will be very happy with the end product!

07/17/2005, 01:31 AM
Get your web guy to finish the page yet? I've been watching/waiting in the dark, since the get go :D Definitly interested.

07/17/2005, 06:17 AM
I am actually taking pictures today so we should start seeming something soon!

07/17/2005, 11:12 PM
Excellent, can't wait :D

08/04/2005, 07:49 PM
Tank is going live with this weekend. Here is the pics of the bottom and back inside.



Still working on the Water change schem and the ability to dim lights on each outlet. On the bottom you will notice the four inputs for probes, and then all the RJ45 type connects used to control four 8 channel outlets. Each channel is defined in the controller which means that on a given outlet a few channels can control lights, a few can control fans, and a few can control valves for CO2 or top off water. Each outlet is hardwired and can be up to 20 feet from the controller.

08/08/2005, 05:36 PM
Got any update?

Will the final version have LCD and manual control.

08/14/2005, 06:50 AM
System is based around being stand alone. PC only uploads the data and displays it. You can also program it via the pv however you do not need to.

Yes final version uses a 4x20 char backlight display.

Runs well. still debugging however. I need to add adjustable control windows. Also just got in my 1 wire digital pots for the light dimmer control

08/18/2005, 04:54 PM
What's the final cost of this DIY controler with all the parts and everything?

09/29/2005, 07:53 PM

It has been about a month since your last update. Any progress to report?

09/29/2005, 08:24 PM
The final production unit has been up and running for awhile. Still a few small software bugs with the Kalk reactor routines but other then that I am happy. I have many things I want to add but it is getting a little out of control.

The current addition is adding moon phase control. Super easy just banging out the code.

Still major issues with self modification of code. You need an 68HC11F1 Compiler such as AVC11 for the firmware and you need VB for the pc end.

For all that is interested PM me.

10/01/2005, 07:21 AM

As you probably already know your mailbox is full. I would like to know the final cost and also if you will provide the programming for it (price?).


10/03/2005, 07:01 AM
Ok I am to a point where I want to wrap up the first phase of this. No Still no Website for this.

The whole purpose of this was to develop a base for the DIY'er to be able to customize a controller for their reef system. Everyone does something different and there is not a controller out there that does everything. I think I have a good base controller that is a good starting point for an open source controller project.

I need to stress that this is not an easy DIY project. You need to have some coding background if you plan on writting code. If yuo have no coding background you might be happy with teh basic kernel it very flexible. You can alwys upgrade the software once there are some open source code developed. It is programmed in AVC11 C for the Firmware and Visual basic for the host PC program. You will also need a compiler for C and visual basic. I can not provide those compilers for obvious reasons.

Those that are interested in this PM me. Understand that all code developed for this must be kept open source.


10/03/2005, 07:03 AM
Let me add that the PCB's for this are not vector or proto board. They are professionally made.

11/29/2005, 09:29 PM
I would be interested i have a lot of proggraming knowledge did 3 years of a CPSC degree and a little IEEE but then decided I wanted to do IT but am still interested in a little challenge. I have even coded in assembly. since you programe that runs on the pc is in vb one could easly incorperate outlook scripts into it. let me know.

12/14/2005, 01:23 PM
Hi Ronc

Hows the Beta board? any ideas on prices and wether I can convert it to 240v 50hz instead of your nicer 110v ??


04/18/2006, 09:02 PM
Sorry for the delay guys. This thread kind of died when I started the other thread. This link below should answer everyones questions.

DIY link (http://www.reefcentral.com/forums/showthread.php?s=&threadid=692306)