Any suggestions for computer monitoring voltages?

[Wolvenar]

I have been trying to find the best ready made solution to monitor a number of voltages via usb on a computer running linux.
I wish to monitor battery voltages and voltages across a shunt to determine amperage.

I also need to control some relays based on a number of factors.
I have been looking at this for some time.
http://www.nbglin.com/usb.htm
But cannot determine for sure how difficult it might be to talk to it without knowing more about the device.
Plus I just cannot shake the feeling that there might be something else out there with more bang for the buck.

Does anyone have any suggestions?

[tomw]

Wolv;

I snagged one of these 4Xrelay USB devices. Works treat for controlling relays.

http://dograt.homelinux.com:8080/products/index.php/menu-controls/menu-4xrelay-usb



Got mine off Feebay for like $35.

It comes with a Linux example source and binary that runs on X86. I couldn't get the source to compile for Arm processor, but I ain't no code monkey so likely me. single pole, with both N.O. and N.C. connections.

I, too, am seeking a Linux /USB solution for monitoring voltages.

Tom

PS.

It works fine without the 12 volt power in. It seems to just feed back out to run through the relays to power stuff? Its been running a week or so here with no issues driving my panels.

[tomw]

Direct link to feebay buy it now & free shipping:

http://www.ebay.com/itm/4xRelay-USB-Control-four-Relay-via-USB-/261042635335?pt=UK_Computing_Other_Computing_Networking&hash=item3cc75a8247

It showed up very fast for a free shipping item.

Tom

[madlabs]

Here, check these guys out:

http://www.dataq.com/usb-data-logger/usb-data-logger.html

Scroll to the bottom. Also:

http://www.dataq.com/usb-data-acquisition/usb-data-acquisition.html

Never had one of their USB products. I do have a two channel to serial ADC of theirs and it always worked well. I used it in my old seismometer at my old place.

Hope this helps!

Jonathan

[tomw]

I have had 4 of those dataQ things not one lasted very long so I gave up on them. Net very good Linux support but you can get them to push info to your computer that you can decode.

They use a common ground so its very limited on flexibility. Like you can't monitor different battery banks unless you want a common ground between them. I don't want that kind of thing.

Accuracy and drift are bad, too. IMHO.


Tom

[madlabs]

That's a bummer. The one I had I bought years ago, guess they've gone down the crapper like much of the rest of the world... 

[tomw]

That's a bummer. The one I had I bought years ago, guess they've gone down the crapper like much of the rest of the world... 

Yeah, everything seems to be bottom line driven these days so quality suffers.

Lots of buying out a good company with customer trust then milking it dry by passing off substandard crap with the "good" name on it.

I almost grabbed another but decided good money after bad is not a sane approach.

There is always the serial port capable handheld voltmeters but they are a kludge and expensive.

Hoping something gets posted in here so I can get back into computer monitoring.

Tom

[Wolvenar]

Well for now I purchased one of these
]


This thing lends itself to way to many possibilities to pass up.
Of course any code or scripts I come up with I'll gladly share with the world.
Hopefully this doesn't turn into a nightmare. 

I'm still looking for alternatives though so please pitch in if you have anything.

[tomw]

Well for now I purchased one of these
]


This thing lends itself to way to many possibilities to pass up.
Of course any code or scripts I come up with I'll gladly share with the world.
Hopefully this doesn't turn into a nightmare. 

I'm still looking for alternatives though so please pitch in if you have anything.

Whatever you do, don't tell us wtf they are or where to get them.

Seriously.

Tom

[Wolvenar]

Sorry, my bad I guess.
My first post with link and my last post had a clickable image bringing you to the site.
I guess I thought that would be enough

Anyhow
Here is one currently on ebay, the seller relists when one is sold so just search if this gets sold.
This is another site with them plus software and specs (as posted before)
http://www.nbglin.com/cpjsimage/usbtool2.JPG

From the ebay listing

5 Major Basic Function:

A. Four Ports Relay Control by Computer
B. One Ports Relay Control with 3 difference period setting
C. Square Wave Signal Generator 5 Hz,10 Hz,50 Hz,100 Hz,200 Hz, 500 Hz,1K Hz,2K Hz,5K Hz,10K Hz,20K Hz, 50K Hz,100K Hz,200K Hz,1M Hz,2M Hz
D. Act as Tachometer for counting the number of rotation
E. 8 Ports Voltage Meter (Voltage Range: 0-60V)

*Post is not finished*

[rossw]

About 18 months ago, I got some small and modest-cost boards. They have 8 digital inputs, 8 digital outputs, 4 analog inputs (one is set up for 0-3.3V, the others are 0-10V) and 8 temperature (DS18B20) inputs.
The new version of this board will also accept a second ADC for another 4 channels, I believe.

DOESN'T have USB, but to me that's a good thing. I hate USB. It does have Ethernet though. You can query it over the net (linux, windows, whatever you want) and set outputs. It can operate stand-alone. It has about 4,000 lines of PLC code memory so you can load a whole bunch of smarts into it and leave it do its thing (if voltage gets below X for Y time, and temperature 1 is below z degrees then turn on output n, and send an email) - all while being able to monitor it remotely.

Here's one I've mounted up in an IP67 box, along with 4 output relays and a 3G cell-router to talk to it.


Cost varies depending on who you get them from, but $50-$70 is about right.

For measuring a shunt, you'd need an amplifier, Tom. Or... use one of the hall devices. The ADC is only 10-bit which is a bummer, but most inexpensive stuff seems to be.

[Wolvenar]

@Ross
I like your setup, i may get more info from you in the future as I expand my setup.

In my case for now it's a matter of least power costs.
This PC is already located in a perfect spot for the job, and having essentially unlimited resources for any code/logging I desire is also a plus to me.

[rossw]

In my case for now it's a matter of least power costs.

Yep. Same. I run 100% totally, completely, entirely off-grid, so I am fully aware of the concerns.
I have currently 6 of these running here (without the 3G option, directly cabled in to my network).
Partly because my house is so damn long (over 150 feet end to end), and I'm monitoring 45 important temperature points (I think I've posted some of that stuff on the forums already). This lets me monitor analog inputs and temperatures, without long input leads, and without putting all my eggs in the one basket as it were.
The boards draw a couple of watts each.

[tomw]

Sorry, my bad I guess.
My first post with link and my last post had a clickable image bringing you to the site.
I guess I thought that would be enough

I can't see a difference between a photo as an external link and the "default" expand photo pointer.


I usually don't expand photos.

Now a normal link would be dead obvious and I would have clicked it.   The first one with link was "I am looking at" no mention of purchase. I am easily confused and my clairvoyance ability has been disabled.

Off topic...

Did you look at that screenshot with the web bugs listed as coming from AP web pages? Curious on when those snuck in?

Thanks.

Tom

[tomw]

@Ross;

I thlnk we discussed this unit before just don't recall the name and unless you hid a link in your post it is not there?

Web based and low power is a real good setup. Takes the "OS support" out of the picture and allows remote operation.

You probably told me sometime but where do I find them?

Thanks.

Tom