Wiring connections are as follows:
- Fona Vio -> Flora 3.3v
- Fona RX -> Flora D10 (configurable)
- Fona TX -> Flora D9 (configurable)
- Fona Key -> Flora GND
- Fona RST -> Flora D6 (configurable)
- Fona GND and BAT -> Flora JST port
Flora can only be powered from the JST or USB port, so solder a JST cable to Fona’s Bat and GND connections and plug it into Flora.
This wiring configuration takes advantage of Fona’s onboard USB lipoly battery charger. But it does mean that either a battery or USB power must be connected to Fona even when Flora is plugged into USB for debugging-- Fona can’t be powered from Flora’s USB port.
Solder the other wire connections as described in the circuit diagram.