The PmodWiFi provides Wi-Fi access through the Microchip MRF24WG0MA Wi-Fi radio transceiver module. Users can communicate with the IEEE 802.11g compliant chip through SPI and achieve data rates up to 54 Mbps.

Functional Description

The PmodWiFi provides IEEE 802.11b/g/n support for embedded applications at data rates of 1 and 2Mbps. It is designed for use with Microchip microcontroller families (PIC18, PIC24, dsPIC33, and PIC32) and the Microchip TCP/IP Stack (a free Microchip Application Libraries download including example applications and source code).

Interface

The primary communications interface with the PmodWiFi is an SPI bus. An RST pin provides the host with an active low, asynchronous hardware reset for the PmodWiFi. The PmodWiFi also provides an active low interrupt indicator pin (~INT), which is asserted low by the PmodWifi when data is available for the host device. The ~INT line is de-asserted high after the data transfer is complete. The SPI SCK speed can be up to 25 MHz.
 

The SPI interface standard uses four signal lines. These are slave select (~SS), master out slave in (MOSI), master in slave out (MISO), and serial clock (SCK). These signals map to the following signals on the MRF24WB0MA: ~SS corresponds to the Chip Select signal (~CS), MOSI corresponds to Serial Data Input (SDI), MISO corresponds to Serial Data Output (SDO), and SCK corresponds to the Serial Clock signal (SCK).

Power Supply

The PmodWiFi is designed to work with Digilent microcontroller boards that have 12-pin header connectors.

The PmodWiFi requires a 2.7V-3.6V supply voltage. A 3.3V power supply voltage is available on all Digilent system boards and is provided as part of the 12-wire Pmod interface standard.

Digilent system boards with Pmod interface connectors allow jumper selection of the power supply voltage being provided to the Pmod. Ensure that the system board is jumpered to provide 3.3V to the module before applying power to the board.