Next week I’m deploying several units – Mayfly with XBee using Hologram SIM, logging data from CS451 SDI-12 pressure transducers. They are replacing old 12v systems with Microhard 3G modems and CR300 Dataloggers. The old modems are power hungry and unreliable. The AT&T service is expensive and 3G will go away eventually. The dataloggers have trouble switching power to the modems and their solar charging circuit is unreliable. So I’m getting more reliability at a FAR lower equipment cost and monthly charge while using the existing sensors, enclosures & power (solar/12v batteries). I’m also getting more flexibility since I own the Mayfly sketch and the Internet server code.
I’d like to confirm a few things I think I know before connecting the power of Mayfly v0.5b:
1. the Ext 12v input will NOT charge a connected Lipo battery.
2. the voltage on the solar JST must be <= 6v, not the 20v-1a that’s listed on the LIPO CHARGER section of the hardware diagram
3. best option is to use a 12-5v USB charger (that Shannon has suggested in other posts) to power the Mayfly and charge the Lipo.