Communication; Usb-Uart; Usb - Mikroe EasyAVR PRO v8 User Manual

Communication

Communication connectors allow the development board to be connected
with many different devices that use high-layer communication protocols
such as Ethernet, USB, etc. Also, there is a USB-UART converter, offering
simplified communication with the personal computer over the emulated
serial interface. Each of these connectors will be described in more details, in
the following sections of the manual.

USB-UART

UART (Universal Asynchronous Receiver/Transmitter) interface is one of
the most common interfaces for data exchange between the MCU and
other external devices. EasyAVR PRO v8 development board offers the UART
connectivity over the USB-C connector
USB-UART bridge IC, produced by FTDI Chip. This IC contains the complete
USB stack necessary for the interface bridging between the UART peripheral
of the MCU and the USB interface of the PC. FT230XQ drivers are available for
download from the EasyAVR PRO v8 product web page, as well as from the
official FTDI drivers download web page.
To enable data exchange via the USB-UART connector, the MCU UART
peripheral lines must be connected to the corresponding pins of the FT230XQ
IC. This can be done using the four-pole DIP switch, labeled as USB/UART
(SW2 on the schematic). Only two switch positions are used for the UART
setup:
SW2.3 ON (up): connects the UART TX pin from the MCU to the FT230XQ IC;
OFF (down): disconnects the UART TX pin from the FT230XQ IC
SW2.4 ON (up): connects the UART RX pin from the MCU to the FT230XQ IC;
OFF (down): disconnects the UART RX pin from the FT230XQ IC
(1) by utilizing the FT230XQ, a popular

USB

USB (Universal Serial Bus) is a very popular industry standard that defines
cables, connectors, and protocols used for communication and power
supply between devices. USB-C (USB Type-C connector) is the latest
version of the USB connector, developed by the USB Implementation Forum
(USB-IF). Due to its many advantages including symmetrical pinout, higher
current capacity, and faster supported data rates, it is probably going to
replace all the previous USB connector types. USB-C connector supports
both USB HOST and USB DEVICE modes. This enables MCUs equipped with
the USB (2) peripheral to act either as a USB HOST or as a USB DEVICE,
allowing development of a range of various USB based applications.
The USB mode selection is done using an a specialized controller IC solution.
This IC provides Configuration Channel (CC) control logic detection and
indication functions. The HOST/DEVICE detection pin (USB ID), as well as the
HOST/DEVICE configuration pin (USB PSW) of the MCU, can be connected
with the logic control circuit by using the DIP switch (SW1), located in the
BOARD SETUP section:
SW2.1 ON (up): connects the HOST/DEVICE configuration pin of the MCU
with the PTN5150 logic control circuit;
OFF (down): disconnects the HOST/DEVICE configuration pin from
the PTN5150 logic control circuit
SW2.2 ON (up): connects the HOST/DEVICE detection pin of the MCU with
the logic control circuit;
OFF (down): disconnects the HOST/DEVICE detection pin from the
logic control circuit
To set up EasyAVR PRO v8 development board as the USB HOST, the PSW pin
should be set to a LOW logic level (0) by the MCU. If set to a HIGH logic level
(1) the development board acts as a DEVICE. In HOST mode, EasyAVR PRO
v8 development board provides the power over the USB-C connector for
the attached device. The USB ID pin is used to detect the type of the device
attached to the USB port, according to USB OTG specifications: the USB ID
pin connected to GND indicates a HOST, while the USB ID pin set to a high
impedance state (HI-Z) indicates that the connected peripheral is a DEVICE.
E a s y A V R P R O v 8 M a n u a l