Im a newbie, just joined up, im looking at using Arduino 2009 and LCD sheild, for a monitoring device for a small stand alone Solar and Battery setup at a remote location, would like to have some data logging to a SD Card and read later on a laptop.
need current range 0-20amps for charging current, 0-40 amps load current, looking at using iron core toroids and hall effect sensors for DC current Transformers, and resistors to scale 0-30 volts to 0-5 v analouge inputs
I have some ideas, but need some help to start.
Regards
Frank
Melbourne AU
A couple of these might be just what you're looking for. Note the "couple": it's a unipolar sensor, so you'll need one for the panel-to-battery path, and one for battery-to-load.
The ACS712 can to +-30A, Allegro make a large version but I can't remember the part number.
EDIT: Found it ACS758, version up to +-200A but the smallest does +-50A which would be just right.
Rob
For the record-to-SD requirement...
On option...
(That shield also gives you a RTC, which might be useful)
With ANY use of an SD card, as far as I am aware, you need to design carefully so that there is provision to write buffers to the card before it is removed.... Like the "safe to remove" procedure with thumb-drives and Windows (and other OSs? "Mount"/"dismount")
If you are interested in the SD side of your design question, perhaps a separate thread would be a good idea? And if you do that, remember that you can edit your first post in THIS thread to avoid "thread fray".
This is also an Option: