Danny_Payne
Posts: 3
Joined: Tue Aug 28, 2012 12:59 pm

Solar monitoring?

Tue Aug 28, 2012 2:08 pm

Hey all, I'm new here so if I posted in the wrong place, feel free to move!

I've had my Pi for a while, probably since mid July, awesome device, really really nice.

Last weekend we had a solar system fitted, 16 panels and an inverter box. On the bottom of the box is an RS232/serial port, you can connect this to a Windows machine and view stats of the inverter box like total power output, how much it's generated and how much it's generating now, graphs, etc.
It also has 2 RS485 plugs on the bottom, can't say I've heard of that but thought I would include.
Manual HERE that includes info on that on page 29. Our model is the SR4K4TLA1.

I'm wondering if I can use my Pi to monitor the system like I would with a Windows machine. Ideally I'd like to either be able to view this info through a local webserver on the Pi, or through a local IRC network the Pi can connect to, like typing a command and the Pi spit out the info on the channel.

I'm completely new to all of this, and have no idea where to start, even if I can use serial on the Pi.

Any help would be great,
Cheers guys! :)

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Jim JKla
Posts: 2218
Joined: Sun Jan 29, 2012 11:15 pm
Location: Newcastle upon Tyne UK

Re: Solar monitoring?

Tue Aug 28, 2012 3:01 pm

RS485 is not that different from RS232 it just allows for a longer cable and or environment with mor RF interference. I was involved in a project to put networked barcode readers into a plant that made radiators including some within 15 foot of a spotwelding doing multiple simultaneous spot welds. It was a fun job. The plugs were the same as RS232 Dtype 9pin as you can get 50 foot (15 Meters) out of an RS232 I think you can ignore RS485

if you are dertermined there are plenty of RS232 - 485 converters

That was about twelve year ago and we would proably do it differently now.

Look for an rs232 to USB converter you may even find one with some Linux software support ;)

Here is a link to some generic support

http://blog.mypapit.net/2008/05/how-to- ... buntu.html
Noob is not derogatory the noob is just the lower end of the noob--geek spectrum being a noob is just your first step towards being an uber-geek ;)

If you find a solution please post it in the wiki the forum dies too quick

Danny_Payne
Posts: 3
Joined: Tue Aug 28, 2012 12:59 pm

Re: Solar monitoring?

Tue Aug 28, 2012 6:50 pm

Sounds good, I think I have a spare one laying around somewhere, will have a look. If not they're cheap enough from Ebay or Maplins.

As for getting the data from the Inverter, would I be able to use Wine and install the program on there that way? Or is there a cleaner way to do it?

Bert_be
Posts: 2
Joined: Tue Aug 28, 2012 6:28 pm

Re: Solar monitoring?

Tue Aug 28, 2012 7:10 pm

Hi Danny,

I've bought one of my Pi's for exactly the same reason!

I've got a solar inverter that's equiped with an RS485 port. The manufacturer provides Windows software but there are several alternatives for Linux.

BUT... the Raspberry Pi has problems with serial communication over USB!
I've even bought 2 different cables (FTDI FT232RL and Prolific PL-2303).

The Pi just becomes unresponsive ("hangs") after a couple of seconds of serial communication.
When this happens it isn't even possible to log in with SSH.

There are discussions about this in several threads. Here's one of them.

I hope this get's fixed soon...

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Jim JKla
Posts: 2218
Joined: Sun Jan 29, 2012 11:15 pm
Location: Newcastle upon Tyne UK

Re: Solar monitoring?

Tue Aug 28, 2012 10:39 pm

The answer may be in either going to pure RS485 and or access via GPIO.

The RPi is effectivly in pre-release mode.

Remember the main eddition is the planned "A" and you could say we are just breaking ground with the "B"

Some 18 Months down the road some whizz of a 14 year old may write some super neat code that connects your RPi model "A" wirelessly to a dongle that plugs into your RS "whatever" connection.

OK the 14 yearold may charge an arm and a leg for the software but we will probably find one of us oldies can reverse engineer it and print a Gnu version on a 3D rep-rap printer :D
Noob is not derogatory the noob is just the lower end of the noob--geek spectrum being a noob is just your first step towards being an uber-geek ;)

If you find a solution please post it in the wiki the forum dies too quick

Bert_be
Posts: 2
Joined: Tue Aug 28, 2012 6:28 pm

Re: Solar monitoring?

Wed Aug 29, 2012 7:05 am

Jim JKla wrote:The answer may be in either going to pure RS485 and or access via GPIO.
... and that's why I'm keeping a close eye on the RasPiComm board
(but this will bring the total cost of my little project up to (or over) the price of a second hand plug-and-play solution for my solar inverter)

Danny_Payne
Posts: 3
Joined: Tue Aug 28, 2012 12:59 pm

Re: Solar monitoring?

Thu Aug 30, 2012 12:47 pm

Late reply.

So this could be possible? How would I go about connecting the unit to the Pi's GPIO pins thru RS232?

I have no idea what I'm doing here so any info would be cool :)

catmaker
Posts: 50
Joined: Thu May 24, 2012 8:32 am

Re: Solar monitoring?

Thu Aug 30, 2012 1:24 pm

Danny_Payne wrote:Late reply.

So this could be possible? How would I go about connecting the unit to the Pi's GPIO pins thru RS232?

I have no idea what I'm doing here so any info would be cool :)
You can try one of the few RS232 breakout boards on RPi Expansion Boards: look through for the boards that mention RS232 and that board will probably convert the GPIO UART pins into the RS232-levels required for connection to your device. (I risk "advertising", but mine is listed on that page as the second last one :| )

tasminracer
Posts: 2
Joined: Fri Aug 24, 2012 8:52 am

Re: Solar monitoring?

Wed Sep 26, 2012 2:31 pm

I've just bought a piglet board that has rs485 on it, and im going to try and figure out how to talk to the data stream from an sma inverter.

anyone else tried it

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anwmalos
Posts: 19
Joined: Wed Nov 16, 2011 12:13 pm
Location: Greece
Contact: Website

Re: Solar monitoring?

Wed Sep 26, 2012 8:40 pm

Hello,

I have no problem connecting usb2serial on the raspberry pi, it seems strange that you mention it. Actually, right now I have one PL-2303 converter connected, with an application banging bytes out the serial and there seems to be no problem. (FYI I have the latest raspbian installed)

Nevertheless, the addon board I am most expecting is here: https://amesberger.wordpress.com/ with rs232, rs485 and native raspi support. Not the only one, but a cool one...

Now on to a shameless plug: http://www.raspberrypi.org/phpBB3/viewt ... 37&t=11955

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