I study the movements of fish in freshwater ecosystems in Alaska, USA. We use RFID readers from the cattle industry. The readers power antenna arrays, and when a fish with an RFID tag swims over one, the reader sends a tag code over serial communication.
Right now we use a buggy software program and old Dell Axim PDA’s to record the tag code and give it a timestamp. The PDA’s are the weakest link in our system and I want to replace them with a more simple, cheaper data logger.
I have a couple Arduino Unos that I use in camera traps and I absolutely love them–I’d like to see if I can use them for this research project as well. I have 2 major criteria:
Serial communications: I need a datalogger that can receive serial communications from 2 RFID readers at the same time. When it gets a tag code from reader A (which won’t be identified as such) it needs to record: reader A, tag code, and the time of the read. Ideally it would have some sort of traffic control so that if it receives reads from both readers at the same time, it will record both. The RFID readers have 3 comm wires (in, out, ground) that we currently tie into an RS-232 adapter.
Clock: Having a reliable clock is critical, since the Arduino would need to record a timestamp for each tag code it gets from the RFID reader. We are monitoring for 3 months. Time drift of <30 min. across that time would be acceptable. The RFID sites are in extremely remote areas, and powered by 12V 50ah batteries. It would be nice if I could switch batteries (power on/off Arduino) without the clock resetting. We visit the sites every 7 days to change the 6V batteries that power the RFID readers, but ideally the dataloggers would go 2 weeks+ on a 12V 50 ah battery.
Thanks a lot for any advice on whether the Arduinos would be suitable for this project.