Many modern microcontrollers feature USB ports that can serve various purposes such as programming, debugging, keyboard or disk drive emulation, and data transfer between a computer and firmware. However, with the addition of a USB Host port, your microcontroller project can also support peripherals like keyboards, mice, and disk drives, greatly expanding the range of devices you can integrate. The Adafruit USB Host FeatherWing simplifies the process of adding USB Host capabilities, particularly with the recently added support in the Arduino library via TinyUSB.

The Adafruit USB Host FeatherWing with MAX3421E utilizes the reliable MAX3421E chip for USB host functionality. Data is transmitted through SPI and an IRQ pin, allowing for use with various USB devices. While the chip may not support high speed 480Mbps data transfer due to its age and limitations of the SPI port speed, it is still effective for basic HID interfacing and reading/writing to Mass Storage devices. An established USB Host Library with AVR support is available, along with compatibility for nRF52 and ESP32. However, we suggest using the TinyUSB Arduino library if the chip already supports it - ideal for RP2040, ESP32-S2 or S3, nRF52840, SAMD21/51 chips. Be sure to confirm compatibility with your desired Feather mainboard before purchasing. 

Featuring a 5V 1A booster with a 500mA fuse, along with the MAX3421E, this product provides a stable and efficient power supply from either USB or Battery. Additionally, a convenient enable pin allows for power cycling when needed.

This assembled Wing comes with headers included. Simply solder on the headers and connect to a Feather Mainboard for expanded capabilities. Ensure you have driver support for the MAX3421E (refer to known working chips) and if using a specific mouse, keyboard, CDC serial, or USB mass storage device, a USB driver is required. Writing a driver is a complex task.