Firstly, welcome to the land of Arduino.
Secondly, can I suggest you re-name the title of this topic, 'Newbie Project' is pretty bland and does not convey anything about the topic.
To suggest a better heading, try 'Solar System Monitoring'
Did you read 'How to use this forum - please read' sticky first, it really might be worth your while as a 'newbie'?
Radmacdaddy wrote:
I live offgrid in N. Ireland and I have a small solar array I wish to monitor
When you say 'small', can you quantify that for us, how small?
For measuring the input current form your solar panel you really should look at using uni-directional current sensing devices.
The link you gave for the Allegro current sensors are nice units but as you can see, they only have bi-directional units available.
I have been watching for some months the same units, and it seems the uni-directional sensors are not so readily available.
If you were to use a bi-directional sensor, you end up wasting half your available resolution, as you only measure current going from the solar panel towards your battery, and never the other way around.
Depending on the size of your maximum solar input current in Amps plus a little extra, you again need to match that to an appropriate sensor range.
If your max solar input current is say 50 Amps, then I believe the 50 Amp uni-directional sensor would be a good choice.
If your max solar input is only 10 Amps, then it would be wise not to use such a device as you will again loose much of your available span range and need to use some extra circuitry such as an op-amp to provide the necessary gain to match the input span of the analogue input on your Arduino which is 0 to 5 Vdc, otherwise you will only record large steps of input current change instead of more accurate finer points of change.
I will hope to make my code available soon for the system I am working on, the link is in my signature.
I am at close to the stage of installing the current sensing section, though I will be using the smaller ASC712 units.
Paul