Adafruit’s Feather development boards are a popular alternative to the Raspberry Pi platforms, which can be powered via USB or LiPo batteries. While they can be utilized for nearly any project, they are limited in the number of power options that can be used to drive the boards. Hardware engineer David Wilson solved that problem by designing his Buck-Boost FeatherWing that allows users to use nearly any 2 to 15V alkaline batteries.
The board itself conforms to Adafruit’s Feather form factor dimensions and is outfitted with a barrel jack that accepts DC power input. The board features Texas Instruments’ TPS63070 buck-boost switching converter, which converts the DC input into 3.3V, and outputs to the 3.3V pin of the Feather stack.
“The TPS63070 switching converter can start operation at any input voltage from 3V to 15V; once started, the TPS63070 will continue to run down to 2V if the supply is not interrupted. In this way, a battery can be almost completely drained before discarding,” Wilson notes. “This board shares the Feather pinout and, depending on the headers installed, can be stacked above or below the Feather board and any optional wings. It should not interfere with the function of any of the digital or analog pins.”
Beyond the buck-boost converter and barrel jack, the board includes a Power Save mode for low-load efficiency, a jumper option to force PWM mode for high-load efficiency, a slide switch to select switcher or LDO operation, reset pin, and battery monitor pin. Wilson has uploaded an extensive walkthrough of his Buck-Boost FeatherWing on his project page for those who would like to recreate his build.