Bluetooth®
The RN4678 is a fully certified Bluetooth Dual Mode (BR/EDR/LE) module, enabling easy-to-use classic Bluetooth and Bluetooth Smart capability. In the MTB Standard UART interface at 115200, the baud rate is set to send and receive data to the RN4678 Bluetooth module. With the default firmware, the RN4678 Bluetooth module will connect to any PC with these settings without the need for flow control.
USB
The USB peripheral support in the SAMD21 device offers both peripheral device and embedded Host modes having eight endpoints/pipes (each address having one input and one output endpoint). The USB peripheral uses Direct Memory Access (DMA), which reads and writes to the internal SRAM during a USB transaction without CPU intervention to optimize the endpoint/pipe data transfers. In addition, the USB peripheral also has support for ping-pong operation and multi-packet transfers, reducing the number of software interventions and interruptions required to manage a USB transaction.