Datasheet

chipKIT™ Wi-FIRE™ Board Reference Manual

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Connectors J7 and J10 are 2x8 female pin header connectors that provide digital I/O signals. The outer row of pins

(closer to the board edge) corresponds to the I/O connector pins on an Arduino Uno or Duemilanove board. The

inner row of pins provides access to the extra I/O signals provided by the PIC32 microcontroller.

Connector J8 is a 2x6 female pin header connector that provides access to the analog input pins on the

microcontroller. The outer row of pins corresponds to the six analog pins on an Arduino Uno or Duemilanove. The

inner row of pins is for the additional I/O signals provided by the PIC32 microcontroller. The analog pins on J8 can

also be used as digital I/O pins.

The chipKIT/Arduino system uses logical pin numbers to identify digital I/O pins on the connectors. The logical pin

numbers for the I/O pins on the Wi-FIRE are 0-42. These pin numbers are labeled in the silk screen on the board.

Additional pins 43-70 allow access to the on board components such as the uSD, MRF24 WiFi radio, User LEDs /

BTNs, and POT.

Pin numbers 0-13 are the outer row of pins on J10 and J7, from right to left. Pin numbers 14-19 are the outer row

of pins on J8, from left to right. Pins 20-25 are the inner row of pins on J8, from left to right. Pin numbers 26-41 are

the inner row of pins on J10 and J7, from right to left. Pin 42 is the pin labeled A on J7. This pin is normally the

reference voltage for the microcontroller’s A/D converter, but can also be used as a digital I/O pin.

In addition to the connector pin, Pin 13 also connects to the user LED LD1. Pin 43, 44, and 45 connect to user LEDs

LD2, LD3, and LD4. Pins 43-45 do not attach to any connector. Pins 46 and 47 connect to Buttons BTN1 and BTN2

and do not attach to any connector.

The analog inputs on connector J8 are assigned pin numbers. The outer row of pins on J8 is analog inputs A0-A5.

The inner row of pins is A6-A11. These pins are also assigned digital pin numbers; A0-A5 are digital pins 14-19, and

A6-A11 are 20-25.

6 802.11b/g Interface

The 802.11b/g compatible WiFi interface on the Wi-FIRE is provided by a Microchip MRF24WG0MA WiFi module.

This module provides the radio transceiver, antenna, and 802.11 compatible network firmware.

The MRF24WG0MA firmware provides the 802.11 network protocol software support. The DEIPcK and DEWFcK

libraries provide the TCP/IP network protocol support that works with the 802.11 protocol support provided by the

WiFi module.

The primary communications interface with the MRF24WG0MA WiFi module is a 4 wire SPI bus. This SPI bus uses

SPI4 in the PIC32 microcontroller, and this SPI controller is dedicated to use for communications with the WiFi

module

The WiFi module supports SPI clock speeds up to 25MHz. In addition to the SPI interface, the interface to the WiFi

module also includes a reset signal, an interrupt signal and a hibernate signal. The active low RESET signal is used

to reset the WiFi module. The external interrupt signal, INT, is used by the module to signal to the host

microcontroller that it needs servicing by the microcontroller software. The INT signal on the WiFi module is

connected to external interrupt INT4 on the PIC32 microcontroller and is not routed to any connector. The active

low HIBERNATE signal is used to power the WiFi module down and puts it into a low power state.

The interface signals to the WiFi module are controlled by the network libraries and are not normally accessed by

the user sketch. Refer to the schematic for the Wi-FIRE board for details on these connections.