The most commonly confused part of the Flora is the VBATT pad and how power management is handled in the Flora. We designed the flora to be mainly powered via the JST connector. You can power it with a battery pack or lipo battery. That input is polarity protected and also controlled via the on/off switch. The battery output after the switch is VBATT. You shouldn't use VBATT as an input as you might damage your battery if you also plug in the USB connector to a computer! The ideal use of VBATT is when you want to power something like NeoPixels or a servo, something that requires more than the 150mA available from the onboard regulator.
The Flora also supports hardware SPI. The SPI pins are on the 2x3 header near the center of the Flora. A small white dot indicates pin 1. The SPI header pinout is shown here:
- Battery input (JST): 3.5-16V (the regulator is MIC5225-3.3) with reverse polarity protection, 2A max rated connector. We recommend no more than 6VDC so that the 3.3V regulator does not overheat
- USB input: 4.5V-5.5V with 500mA fuse
- 3.3V output pad: we recommend no more than 100mA, as the regulator can supply 150mA and the Flora Mainboard uses 20mA. but you can probably draw up to 250mA in spikes
- Clock speed: 8MHz
- Chipset: ATmega32u4
- VBAT output pad: the higher of the VBAT JST input voltage and USB voltage (two schottkey diode connection)
- Current Draw: 8mA quiescent, another 2mA when the pin #D7 LED is on.