Digilent chipKIT Network Shield Manual de referencia - Página 7

Navegue en línea o descargue pdf Manual de referencia para Hardware informático Digilent chipKIT Network Shield. Digilent chipKIT Network Shield 11 páginas. Chipkit network shield board
También para Digilent chipKIT Network Shield: Manual de referencia y guía del usuario (11 páginas)

Imprimir página

chipKIT™ Network Shield™ Reference Manual

When using the Max32/Network Shield within the MPIDE environment, the boot loader on the Max32 boards sets

this configuration automatically. When using the boards outside the MPIDE environment, you must configure this

setting.

The pins on the PIC32MX795 microcontroller used by signals for the CAN1 controller to connect to its transceiver

are shared with two of the signals for UART3B and SPI port 3A. These signals appear on pins 14 & 15 of connector

J4 on the Max32 board. Jumpers JP1 and JP5 enable you to use these pins if neither of the CAN networks are

needed. There are cuttable traces on the bottom of the board between the pins of JP1 and JP5. Cut these traces to

disconnect the transceiver for CAN1. To restore the connection, load two pin headers for JP1 and JP5 and install

shorting blocks on the two jumpers.

Pins 15 and 16 on the PIC32MX795 microcontroller are used by the CAN2 signals and appear on connector J13 on

the Network Shield (connector J9 on the Max32). They are digital pins 22 and 23 and are not available for any

other use when using CAN2.

There is no standard connector for use with CAN networks. The Network Shield has two 2x6 pin header connectors

for access to the CAN signals. Connector J3 provides access to the signals for the CAN1 network controller, and

connector J5 provides access to the signals for CAN2. Refer to the schematic for the Network Shield or the tables at

the end of this document for information on the connectors and signals. A Digilent 6-pin or 2x6 to dual 6-pin cables

can be used to daisy chain Digilent boards together in a CAN network. A Digilent 6-pin cable and a Digilent

PmodCON1 Screw Terminal Connector module can be used to connect the Max32/Network Shield to other

network wiring configurations.

The CAN network standard requires that the nodes at each end of a network provide 120-ohm termination. The

Network Shield provides the termination resistors and jumpers to enable/disable them depending on the location

of the board in the network. Jumper JP2 is used to enable/disable the termination resistor for the CAN1 network,

and JP7 is used to enable/disable the termination resistor for CAN2. Install a shorting block on the jumper pins to

enable the termination resistor, or remove the shorting block to disable the termination resistor.

2.4

I2C Busses and Connectors

The Inter-Integrated Circuit (I

communications bus. The I

addressing. Each device is given a unique address, and the protocol provides the ability to address packets to a

specific device or to broadcast packets to all devices on the bus. Refer to the PIC32MX7XX data sheet and the

PIC32 Family Reference Manual, both available at www.microchip.com, for detailed information on configuring

and using the I

C interface.

The PIC32MX795 microcontroller on the Max32 provides for up to five independent I

Shield is designed to provide access to two of these interfaces: I

the bus accessed through the standard chipKIT Wire library (see the MPIDE Help reference for more information

on the standard libraries). There are five sets of pins on the board for access to the two I

J16, and J19 provides access to I

#2.

Note that external interrupt 3 and SCL1 share the same pin on the PIC32MX795. External interrupt 4 and SDA1 also

share the same pin. Therefore, external interrupts 3 and 4 should not be used simultaneously with I

One I

C device is provided on the Network Shield, a 256Kbit EEPROM connected to the I

Other product and company names mentioned may be trademarks of their respective owners.

C) interface provides a medium-speed (100K or 400K bps) synchronous serial

C interface provides master and slave operation using either 7-bit or 10-bit device

C port #1 and connector J6 and digital pins 12 and 13 provides access to I

C interfaces. The Network

C #1 (SCL1, SDA1) and I

C #2 (SCL2, SDA2). I

C ports. Connectors J7,

C #1 bus.

C #1 is

C port

C#1 bus.

Page 7 of 10