Assistance needed- building a Controller using a Rasberry Pi or similar

[Norton]

*mods- please move this thread if it's in the wrong section- wasn't sure where to put it

Hi Folks,

I have a project that needs planning to upgrade a control circuit currently using these:

Spoiler: current device

http://www.westsidewholesale.com/intermatic-et70215cr.html

They are basically parking lot light timers or irrigation system timers but I have them in use for a different purpose. They are currently no longer available so I need to come up with an alternative- the replacements from this company will not be useful for me.

Here's the current capabilities of the existing units:
- built in clock
- able to control 2 devices with preset on/off times
- programmable via Windows using a serial port interface (RS232 iirc)
*note- due to the age of the software and hardware the PC used needs a regular serial port,
USB to serial adapter do not work correctly... tried 5 different kinds

What I'm looking for in a replacement:
- Hardware cost under $200 each (basic controller setup)
- programmable thru Windows or Linux
- Direct interface (mouse/kb/monitor) or with a PC via USB/LAN connection
- time based contact closure (dry contact) for a minimum of 2 outputs- expandable for up to 8 outputs would be ideal but not absolutely necessary. Downstream hardware/devices is/are setup separately.
- possibility of adding/programming digital or analog inputs at some point (optional)

My initial thought is trying to setup something using a Rasberry Pi or Intel Atom/AMD E- series but I'm not a programmer so I wouldn't even know where to start?

Thoughts/Ideas???

*note- this is currently a personal project but there is a possibility of going beyond that if we can get a viable replacement working properly.

 

[brandonwh64]

If you are looking for a windows based small form factor, you could get a Minnow Board. (http://www.minnowboard.org/) These are quite powerful and small while using windows OS. You would also need a I/O PLC bus that allows for timing.

 

[silentbogo]

Hi!

There are many options for timer switches.
The easiest, of course, is a pre-made device, but there are almost none with all of your desired features in one package, or at reasonable price.

If you want to make your own solution - it's not hard at all, if you are comfortable with programming and soldering.
I did a similar project for work (required simple schedule-based multi-channel relay switching with UART interface) and it only took around $10 in parts and materials, plus few days of tinkering/soldering/coding.

Basically it boils down to this:
1) You need a multi-channel relay board (either 5V or 12V trigger). There are tons of inexpensive units out there from single- to 16ch units.
2) You will have to use something to drive these relays, like ULN2003 ICs or some small mosfets with >80mA throughput.
3) You can use pretty much any microcontroller or embedded computer you like. All it needs is enough GPIO to drive your # of relays and some interfacing options (e.g. UART, WiFi/Bluetooth/ZigBee, or physical controls).
My last similar project was implemented with ATTiny2313A and few supplementary components to drive an 8-channel relay module depending on sensor inputs or UART commands received from Bluetooth SPP module (activates lights, music, motors etc). So, in my opinion, RasPi or Intel Edison is an overkill for this task.
4) You might also need an RTC, but some microcontrollers already have it built-in (just need an additional oscillator) or write a software implementation (which is pain in the ass but still doable).

I have just started to work on a digital circuit breaker with wi-fi connectivity, so it kinda goes along the same line of tech. If you can tell me more about your project I might be able to help you with implementation or an easier solution.

 

[Norton]

Thanks for the input

Most of what I'm looking for is the ability to program on/off cycles at specific intervals that I can output to close the coil on a relay, which will then activate the device- a pump for example.

The current unit and its software* allows me to program multiple cycles easily (reasonably easily anyway) that I can save, upload/download to each device whenever I need to.
* program saves into an xml format afaik if that means anything?

Will update this post with a screenshot of the cycles for one of these timers a little bit later today- they're in my laptop atm and I'm going out for a few hours shortly...

Basically what I need it to do is:

At a specified time- start a device- run the device for a certain duration (variable/adjustable)- stop the device.... repeat at next programmed time. Each day has up to 72 cycles per device.

In the meantime- See page 6 of the software manual as an example of how it is setup:

http://intermatic.com/~/media/Inter...ries/Next Generation Software User Guide.ashx

 

[silentbogo]

Ok. Got it. It seems like they have a built-in SPI Flash to store the schedule and it is a relatively small chip (probably 1Mbit). I've looked at their new $400 unit and it reminded me of another cool project I've seen recently.

Google an OpenSprinkler project. It is designed to control 24VAC[DC] sprinkler valves, but can be easily modified to run, for example, an array of relays.
This thing is a fully Open Source project and includes tons of features, like USB and Ethernet interfaces, I/O expansion modules, Wireless networking, microSD card slot etc.
Also it has a much more flexible event programming through Web Interface or an Android app, in addition to data logging from external sensors (moisture, temperature etc.).

The retail price is around $155, but you can buy a DIY kit for $90 and solder it yourself : all components are through-hole, so you can make it with a simple $5 soldering iron.

http://rayshobby.net/opensprinkler/

 

[Norton]

The new unit is available easily enough but the programming features don't seem to match what the old one can do.

This is an example of what I have one of these setup to do:

Just using it for starts/stops on a 24 hr clock, I'm not using/don't need any of the other functions.

That OpenSprinkler device looks very interesting- Thanks!

 

[OneMoar]

I think you may want arduino its geared much better for what you want
also way way cheaper something like this
http://www.seeedstudio.com/wiki/Relay_Shield_V2.0
what you could do is the following sheild tree
Arduino }
network shield
Rtc shield
relay shield
and assuming you can code you could work up a simple web-server for remote management
all for well under 100.00 a unit
there is probably somebody someplace thats done exactly what you want
edit: google ftw
http://www.instructables.com/id/Ethernet-Switching-with-Arduino/

 

[silentbogo]

I've scanned through datasheets for both devices and functionally it looks simple enough. I already got some ideas about hardware design, and the software is not rocket science either.

I'll try to come up with a small prototype in a few days. I guess if there is a demand for such things we might turn it into a low-cost product for DIYers!

Getting sleepy now, but I'll try to get schematic done tomorrow.

I'll keep you posted on the progress.

 

[Brusfantomet]

your application screams MCU, my favorit there is the Atmel xmegas (some national pride right there).

for ease of use the Auudrinos are probably a good option.

I have personal experience with the evaluation kit for the xmega-a3bu, winch is probably 10x the capabilities you need.
BUT the board is in its self great. lots of GPIO (3,3 V) 5V to 3,3V, buttons, screen, UHART. USB input for programing/communication.
And you have a adequate IDE for development and loads of examples and a exiting community.

the best part, i got mine for the equivalent for 14 USD. For your use you would need a spearate relay card (easy to make yourself or get form e-bay)

For an alternative, i do not have knowledege of what kind of power we are getting (110V AC/ 12VDC /24VDC) But for that kind of money i could get a WAGO 750-881 CPU and some 750-513 cards (this is a cheap PLC with capabilities a magnitude of price over what you pay for it). we use them all the time for "special" projects at work. this is a profeshonal part tho. and it uses a 24V DC supply. This however uses CoDeSys for programing, not that its bad compared to its competitors but the licensing is not what us normal consumers are used to. And geting help from a google serch requiers some google-fu ( IEC-61131-3 is somewhat different from PC programing, beeing more focued on the real time aspect of it.

 

[Norton]

and assuming you can code you could work up a simple web-server for remote management

I don't code, wouldn't know where to even start

I would need some form of user interface that I could put settings into like the pic in my post above...

 

[Brusfantomet]

I don't code, wouldn't know where to even start

I would need some form of user interface that I could put settings into like the pic in my post above...

Then the xmega i suggested is out, needs some knowledge of C/C++ for the IDE.

As long as you read the help files for the wago tho, you might actually get that to work.

the Audrino is the go to for starting programmers (have seen 8 year olds programing stuff with that in a week) you should be able to get that ball rolling.

Also, if qualifies as a user interface then the atmel it a possibility again.

But from my mind, you are going to end up with a Adrino of some sort, that you are going to hardwire for each spesific use.
Or you are going to learn some simple com interfaces and use it to configure a simple timer based program on the audrino.

 

[Steevo]

https://batchloaf.wordpress.com/201...nding-characters-to-a-serial-port-in-windows/


You could write a simple batch program that queries the system time and sends a specific command to a serial port, looked up out of a CSV table, and the CSV table would be easy to come up with in open office. A simple microcontroller with a switching relay could do the work.

http://stackoverflow.com/questions/...g-from-a-csv-file-and-extracting-certain-data

http://www.robotshop.com/en/12-bit-...p70NqyZXomNBLf4eJ3NA1zGsglzO1NJKl0xoCRAnw_wcB

http://www.omega.com/googlebase/pro...Ziz0Rx13Vxx-2o19VF_ui_GOGPLAboX7o5xoC1yPw_wcB

 

[Brusfantomet]

https://batchloaf.wordpress.com/201...nding-characters-to-a-serial-port-in-windows/


You could write a simple batch program that queries the system time and sends a specific command to a serial port, looked up out of a CSV table, and the CSV table would be easy to come up with in open office. A simple microcontroller with a switching relay could do the work.

That would work.

Then again, we have a saying in norwegian "Skyte spurv med kanon" wich translates to: using to much power it not a good thing. A x86 system will have the power and accuracy to do what he asks, but it will requirer a x86 system. i agree with my self 30 minutes ago (and @OneMoar that a simple MCU, and the simplest there is for the user is the audrino, would suit his needs perfectly. Only problem is that @Norton have limented , "I don't code, wouldn't know where to even start" knowledge of low (correct) level coding) the Audrino is the best option (acesseable price, easy to master and a metric ton of peripherals communicating to the thing). closely folowed my by my one wago solution. Problem is, both require him to actually code the thing himself, and by his own admission, that is a problem. My stand is that beeing an adult with a reasonable understading of things he should be able to us an audrino to do waht he wants (if he gets a fancy one with usb conaction he can make a sple program that sets each timer on the MCU for him).

 

[Steevo]

A old cheap XP system or laptop would work perfectly, and consume a whole 20-30Watts of power to run this, and it would run until hardware failed or the world ended whichever comes first.


If he wanted it could be setup remotely and use Remote desktop connection to run it.

 

[Norton]

A old cheap XP system or laptop would work perfectly, and consume a whole 20-30Watts of power to run this, and it would run until hardware failed or the world ended whichever comes first.


If he wanted it could be setup remotely and use Remote desktop connection to run it.

I have about 10 of the timers I linked to in the OP- they do the job just fine but they are not made anymore. The current replacement model sucks to program so I'm stuck with the old ones and piecing them together from scrounged parts, overpaying for old stock, etc..

All I need the replacement to do is what the old one does and connect with something newer than a serial port.

Kudos to all for the input and discussion so far!

 

[Steevo]

The serial port issues you have had are with cheap serial controllers, and the lack of buffer space ( which makes them cheap). I use Sabrient USB to serial controller cables all the time, and the biggest thing is to use the older driver, and to assign the COM1 port to the USB adapter it will be plugged into, then to tweak the buffers and max speed.

http://www.newegg.com/Product/Product.aspx?Item=N82E16812156008

The new drivers cause the issues with newer versions of windows, especially X64 versions, so using the old driver and not allowing windows update to screw with it is essential.

I would also try to work with AgExpress in Iowa, not sure if you are from the US, but they will fix and or build you anything you want within reason.

 

[Brusfantomet]

A question, what is the nubers to be used here? we talking 1 to 10 for personal/friends use or a system aimed at those havin one of the afomented parts an wanting the same when theirs break down and all the others, meaning 1000 + systems and the backup (or lack thereof) for that?

 

[Norton]

The serial port issues you have had are with cheap serial controllers, and the lack of buffer space ( which makes them cheap). I use Sabrient USB to serial controller cables all the time, and the biggest thing is to use the older driver, and to assign the COM1 port to the USB adapter it will be plugged into, then to tweak the buffers and max speed.

http://www.newegg.com/Product/Product.aspx?Item=N82E16812156008

The new drivers cause the issues with newer versions of windows, especially X64 versions, so using the old driver and not allowing windows update to screw with it is essential.

I would also try to work with AgExpress in Iowa, not sure if you are from the US, but they will fix and or build you anything you want within reason.

Had no luck with that one- the best I could do was establish communications one way with one of the ones I tried. Even tried it with the Dell D610 w/XP Pro that I use now for these (straight serial works perfectly)

A question, what is the nubers to be used here? we talking 1 to 10 for personal/friends use or a system aimed at those havin one of the afomented parts an wanting the same when theirs break down and all the others, meaning 1000 + systems and the backup (or lack thereof) for that?

These are for controlling pumps where I work- will never reach 1000+ units.... couple of dozen at most.

 

[Brusfantomet]

So we are talking something manageable for you alone then.

The idea to use Audrions and specifiably program each one of them for the task seams like the best solution here. you can (if you want) make a general program that is programmable trough some common port (my suggestion would be usb) for the particular configuration.'

the execution here can either give you a nice all purpuse usage timer thing to help you at work, or a highly specialized box that only you understand and gives some position safety.

Also, i am wondering, what is the supplied power here (AC/DC and voltage) and is that cointrol surface going to be used for anything (or are we talking new box, new HMI but same hardware controlled here)?

 

[Aquinus]

So you just need to control 115-230v AC pumps? So you want something like a controller that can handle several SPDT switches based on a real time clock?

Just so I understand the needs perfectly (as well as everyone else,) you're basically asking for something like this: http://www.grainger.com/product/INTERMATIC-Electronic-Timer-3FWZ4
Except with software level flexibility to set up when the timer gets triggered instead of a flat schedule?

 

[Norton]

So you just need to control 115-230v AC pumps? So you want something like a controller that can handle several SPDT switches based on a real time clock?

Just so I understand the needs perfectly (as well as everyone else,) you're basically asking for something like this: http://www.grainger.com/product/INTERMATIC-Electronic-Timer-3FWZ4
Except with software level flexibility to set up when the timer gets triggered instead of a flat schedule?

Something like that yes but with software access to download/adjust/upload the settings to- I run through several timer settings changes a year and hold the current settings, for the old unit. in my laptop for doing the changes, reinstalls, etc...

EDIT- think I found something...

http://www.intermatic.com/en/Produc...l_Timers/TalentoPro_Series/Talento882Pro.aspx

Will look into this one further.