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Paul,

  I can't find a data sheet for the LandStar LS1024B charger. Do you have more info on the charger? It has a RS485 link than could be interfaced to the pi with a plug-in shield. If you haven't purchased the charger someone here may have a solution with the same specifications as the LandStar PWM Solar Battery Charge Controller 10A 12/24V.

  This claim seemed a bit problematic - "Please note that this regulator is not MPPT and cannot accept a higher nominal Voltage than the battery it is charging." Something with specifications like this will me more polite to your batteries, which is a major total cost of ownership expense.

http://www.amazon.com/Morningstar-SL-10L-24V-SunLight-Charge-Controller/...

  Be good to your batteries. MPPT is a good thing, especially if your panels get shaded by clouds. MPPT can improve the overall system efficiency by 20%. That adds up.

  What batteries and solar panels are you using? Can you describe the load.

Sincerely,

Kevin

Hi Kevin ,

Thankyou for your Comment above

This is only a small project , im using a 50w 12v panel and 50ah Gell battery. This is a prof of concept to see if a can have real time monitoring a 12v DC system as the system at Openenergymonitor cant monitor only DC Eg volts,watts,amps from my DC Solar panel and the load(s) from my Battery(s)   also i would like to in the end to have a AC via a Inverter (300w Small Inverter) . My Loads are very small all at the mo are 12v And 5V and under 5 amps apox.

I need a system that can monitor DC side of my system input and output via the OpenEnergyMonitor System via my raspberry PI Model B .

I hope the above info can help someone to help me in this small project .

Many thanks again for all your time and help

Paul

The OEM project CAN monitor dc, but nothing to measure dc is offered in the shop. You've got to do it yourself. If you search the forums, you will find some good information that might help you. As you are thinking very small-scale, I think you need to be looking at invasive Hall-effect sensors and the like for current, and a simple voltage divider for the battery voltage. Both these need to be wired in ("invasive") and due care still needs to be taken when working on live PV systems, but then you will have an output that, possibly with some signal conditioning, can go into an Arduino or similar processor, either fitted with an Ethernet shield or a radio (RFM12B/RFM69CW) shield that can communicate the voltage and current to your RPi. Note that radio is likely to be much easier, it will naturally isolate the two systems from each other and so you won't have to worry about making a common connection between "GND" of your RPi and one side of your battery, which could give you serious problems if you have a wired - serial or Ethernet - connection.

Hi there ,

Ok New Plan Below ..

I have looked around on the net and on this forum for a DC monitor Via a Arduino connected to 2 - 0-20V volt sensors and 1 -  0 -20A amp sensor that will send data to my PI that wil run the openenergymonitor web software so i may monitor incoming PV volts and Amps & Watts and battery status (volts only) but not been able to find what i need(info wise) :-( i know how to connect the sensors but not sure how to get the data from the Arduino to my PI, then getting the PI to read the data , so i may see the data in web based software .

Could someone help me with this - Im sooo close to my goal .

Many thanks again for all your time :-)

Paul

 making a common connection between "GND" of your RPi and one side of your battery, which could give you serious problems if you have a wired - serial or Ethernet - connection.

I thought modern (10base-t) ethernet was transformer isolated at both ends?

Provided we know that there's isolation there to a sufficient voltage, then there shouldn't be a problem. However, caution is always best. What if a screened cable is used and the screen is connected at both ends?

To answer how to get the data to your RPi, do you want a radio connection or wired serial (with the connection warning in mind)? The emonTx (which uses the same processor) uses the RFM12B/RFM69CW radios and you can add the RFM12Pi radio module to your Pi and add in the radio part of the emonTx sketches; or you can do this http://openenergymonitor.org/emon/node/3872
Then you need emonHub in your Pi to forward the data to emonCMS.

Paul,

  If your solar battery charger does not have a simple data communication port like USB or RS485 then using sensors on the PV and/or battery circuit(s) is probably the way to go. Take a peak at the instructables link below. I think it would be a simple project to use an ACS715 or similar current sensor and voltage divider circuit connected to a modified emonTX, which could send data to your pi over a RFM12B wireless link.

http://www.instructables.com/id/DIY-Amp-Hour-Meter-Arduino/?ALLSTEPS

  This is an example of a DC project that uses an ACS715 current sensor:

http://openenergymonitor.org/emon/node/135

  The instructables link is a nice how-to for a system comparable to yours. If you ported this architecture into an emonTX board you would only need to change the software to handle your sensors, scale factors, and the message sent to the pi.

  Your system is small. 5A of DC shouldn't cause much of a ground voltage shift. I imagine this system will only be connected to Earth or utility ground via the emontTX power supply ground or the data cable to a computer. If the system is grounded in more than one place with high current flow the shift could cause funky behavior or damage. For instance, if this was a 450VDC/18A PV circuit, grounding and isolation would be very important considerations. Ethernet on most RJ45 jacks is isolated with a transformer, and fairly tolerant of common mode and ground induce interference. 

  All the above assumes you are OK with having both a sensor board like the emonTX and a pi. If you want to connect some DC sensors directly to a pi check out the analog input shield for the pi in the link below. You could use one of these and interfaces and use the OEM emoncms platform to push your data to a web site dashboard.

https://www.abelectronics.co.uk/products/3/Raspberry-Pi/17/ADC-Pi-V2---R...

Sincerely,

Kevin

Many thanks for all your help :-)

Will keep everyone updated on my project .

thankyou again

Paul