User Manual

P A G E 30

E a s y P I C v 8 M a n u a l

USB ON DEVICE

USB (Universal Serial Bus) (1) is a very popular industry standard that deﬁ nes cables,

connectors, and protocols used for communication and power supply between

devices. USB-C connector (2) 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 support for faster data rates, it

oﬀ ers a signiﬁ cant improvement over the previous versions. This allows MCU devices

equipped with the USB peripheral to connect to an external USB HOST (such as a PC,

Laptop, etc.), allowing the development of USB-based applications. The connection to

the USB HOST is indicated by a yellow LED labeled as VBUS (3), located in the USB ON

DEVICE section, near the USB-C connector.

When a PIC MCU does not support USB interface or USB connection is not required by

application itself, the USB pins should be disconnected from the USB-C connector and

accompanying circuitry. Therefore, the development board oﬀ ers two DIP switches

located in the USB ON DEVICE section (one per group of MCU sockets), allowing to

specify whether these pins should be used for other purposes (i.e. as GPIO lines) or

they should be used as USB data lines:

RA0/RA1 (DIP14, DIP20) (4)

PORTA (up): allows the RA0 and RA1 pins to be used for other purposes

USB (down): connects the RA0 and RA1 pins to the USB-C conn. and accompanying circuitry

RC5/RC4 (DIP28, DIP40) (5)

PORTC (up): allows the RC5 and RC4 pins to be used for other purposes

USB (down): connects the RC5 and RC4 pins to the USB-C conn. and accompanying circuitry

An additional two-pole DIP switch is used to provide an external power source for the

internal USB transceiver of the MCU. When the internal MCU regulator is disabled via

the CONFIG bits, an external power supply must be provided through the VBUS pin

for the internal USB transceiver. Depending on the MCU installed in the speciﬁ c MCU

socket, either RA2 or RC3 pin is used as the VBUS. The development board oﬀ ers yet

another two-pole DIP switch to specify whether these two pins should be used for

other purposes (i.e. as GPIO lines) or they should be connected to an external power

supply for the internal USB transceiver:

P A G E 30

COMMUNICATION

Figure 15: Main board partial left side view