README.md
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Onion-Omega 2 - Feather Adapter

Adapter board adding much needed USB , Lipo , ADC's etc to Onion-Omega form factor and converting it to an Adafruit Feather

Renders

Top Render


Bottom Render


Roadmap Features


USB-Serial adapter on-board for direct access to Onion Serial port - <![CDATA[]]>CP2102<![CDATA[]]>
<![CDATA[]]>3.3v<![CDATA[]]> and <![CDATA[]]>5v<![CDATA[]]> power rails with buck-boost converters and power-path IC's
USB host to expose the Onion USB pins and add USB devices
Power OR from VUSB and VBAT using Dual Common Cathode Schottky - <![CDATA[]]>PMEG4010CPA,115<![CDATA[]]>
Ethernet jack with built-in or external pulse transformer - <![CDATA[]]>Amphenol<![CDATA[]]> or <![CDATA[]]>Hanrun<![CDATA[]]>
Battery charger and buck-boost converter - <![CDATA[]]>BQ25895<![CDATA[]]>
8-channel I2C ADC for the ADC pins - <![CDATA[]]>AD7997<![CDATA[]]>
2-channel I2C ADC for the ADC pins - <![CDATA[]]>MAX11646EUA+<![CDATA[]]> with other Analog pins services by <![CDATA[]]>Onion PCM/PWM<![CDATA[]]> pins.
Dense 20 pin 1.0 mm pitch board-to-wire connector for all pins - <![CDATA[]]>Molex 203566-2007<![CDATA[]]>
Qwiic format JST-SH I2C bus connector - <![CDATA[]]>Qwiic<![CDATA[]]>
USB-host protection using <![CDATA[]]>STF202<![CDATA[]]>
SPI Bus isolation using <![CDATA[]]>74HC367<![CDATA[]]> hex non-inverting tri-state buffer. This can also be used for I2C bus isolation and driving in later revisions using the left over x2 tristate buffers.


Reference Prior Art


<![CDATA[]]>Adafruit ESP32 Huzzah Feather<![CDATA[]]>
<![CDATA[]]>BQ25895 Breakout<![CDATA[]]>
<![CDATA[]]>Qwiic Featherwing<![CDATA[]]>