User Manual

P A G E 28
E a s y P I C v 8 M a n u a l
USB-UART
UART (Universal Asynchronous Receiver/Transmitter) interface (1) is one of the most
common interfaces for data exchange between the MCU and other external devices.
The EasyPIC v8 development board off ers the UART connectivity over the USB-C
connector (2) by utilizing the FT230XQ (3), a popular USB-UART signal conversion
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 offi cial FTDI drivers web
page www.ftdichip.com/Drivers/VCP.htm
To enable UART data exchange via the USB-C connector, RX and TX lines of the MCU
UART peripheral must be connected to the corresponding pins of the FT230XQ IC. Two
ten-pole DIP switches located in the USB TO UART section of the board, labeled as TX
(SW21) (4) and RX (SW23) (5), allow fully independent control of the UART RX and TX
lines, off ering complete freedom of pin selection. The TX DIP switch (SW21) connects
the specifi c MCU pin (labeled next to the related switch) as the UART transmission
line, while the RX DIP switch (SW23) connects the specifi c MCU pin (labeled next to
the related switch) as the UART receiving line. This allows custom UART TX/RX pair
confi guration, allowing the development board to adapt to many diff erent UART pin
confi gurations, found on various PIC MCU devices:
SW21 (TX)
ON (up): connects the respective UART TX pin to the USB-UART conversion circuit
OFF (down): disconnects the respective UART TX pin from the USB-UART conversion circuit
COMMUNICATION
Communication
Communication connectors allow the development board to be connected with many
diff erent devices that use high-layer communication protocols such as USB, CAN, etc.
Also, there is a USB-UART converter, which enables simplifi ed communication with the
personal computer over the emulated serial interface. Each of these connectors will be
described in more detail, in the following sections of the manual.
CAN
Controller Area Network (CAN or CAN Bus) (8) is a serial network technology, originally
designed for the automotive industry, but due to its robustness and noise immunity,
it has become popular in many other applications. The CAN Bus is primarily used in
embedded systems, allowing to establish fast communication between MCUs or other
peripherals, eliminating the need for expensive and complex technology. The CAN
Bus consists of only two wires, allowing both high data rates and message collision
prevention.
The EasyPIC v8 utilizes the MCP2561FD (9), a high-speed CAN fl exible data rate
transceiver from Microchip, off ering support for both CAN and CAN FD (CAN
Flexible Data Rate) for MCUs equipped with the CAN peripheral. The MCP2561FD
transceiver meets all the automotive requirements for CAN FD, exceeding 2Mbps
data rate, featuring low quiescent current, electromagnetic compatibility (EMC), and
electrostatic discharge (ESD) immunity. Some features provided by the MCP2561FD
include:
∫ Optimized for CAN FD at 2Mbps, 5Mbps, and 8 Mbps operation
∫ CAN Bus Pins are disconnected when the CAN transceiver is unpowered
∫ Detection of ground fault
∫ Protection against damage due to short-circuit conditions
∫ Protection against high-voltage transients in automotive environments
∫ Automatic thermal shutdown
SW23 (RX)
ON (up): connects the respective UART RX pin to the USB-UART conversion circuit
OFF (down): disconnects the respective UART RX pin from the USB-UART conversion circuit
UART traffi c is indicated by two LED indicators, located in the USB TO UART section of
the board, near the USB-C connector:
Yellow LED (TX) (6) indicates outgoing data transfer
Red LED (RX) (7) indicates incoming data transfer