Digilent 410-302P-KIT - Manual (Page 13)

WiFire Reference Manual
10.13 RESET
The PIC32 microcontroller is reset by bringing its MCLR pin low. The MCLR pin is connected to the RST pin, as
presented on J5.
As previously described, reset of the PIC32 microcontroller can be initiated by the USB serial converter. The USB
serial converter brings the DTR pin low to reset the microcontroller. Jumper JP2 can be used to enable/disable the
ability for the USB serial converter to initiate a reset.
The RST is connected to pin 3 of connector J5. This allows circuitry on a shield to reset the microcontroller, or to
ensure that the circuitry on the shield is reset at the same time as the microcontroller.
Connector J9 provides access to the SPI bus. Pin 5 provides access to the SPI Slave Select signal (SS).
On Arduino boards, the corresponding connector is also used as an in-system programming connector as well as
providing access to some of the SPI signals. On Arduino boards, pin 5 of this connector is connected to the reset
net.
Some Arduino shields, most notably the Ethernet shield, connect pin 5 to the reset net on pin 3 of connector J5.
This causes the processor to be reset each time an attempt is made to access the SPI port. Jumper JP5 can be used
to break the connection between J9 pin 5 and reset when using Arduino shields that make this connection. JP5 has
a cuttable trace on the top of the board that can be cut to break the connection between SPI SS and reset. JP5 is
not loaded at the factory. To restore the connection, solder a two pin header at the JP5 position and install a
shorting block.
A reset button is located to the right of the MRF24WG0MA WiFi module. Pressing this button resets the PIC32
microcontroller.
11 Microchip Development Tool Compatibility
In addition to being used with the MPIDE, the WiFire board can be used as a more traditional microcontroller
development board using Microchip Development Tools.
Unloaded connector JP1 on the right side of the MRF24WG0MA WiFi module is used to connect to a Microchip
development tool, such as the PICkit™3. The holes for JP1 are staggered so that a standard 100-mil spaced 6-pin
header can fit to the board without the need to solder it in place. Any Microchip development tool that supports
the PIC32MZ microcontroller family, and that can be connected via the same 6-pin ICSP interface as the PICkit™3,
can be used.
Typically, a standard male connector and a 6-pin cable is used with JP1 so that a PICkit™3 can be attached to the
WiFire board.
The Digilent chipKIT PGM can also be used in place of a PICkit3 to program the WiFire with the Microchip
Development tools. The chipKIT PGM has a smaller form factor and does not need a 6-pin cable to connect to JP1.
The Microchip MPLAB X IDE can be used to program and debug code running on the WiFire board. The MPLAB X
IDE can be downloaded from the Microchip website. Please note that Microchip’s MPLAB®V8 and earlier IDEs
cannot be used with the WiFire, as those versions of MPLAB IDE do not support the MZ processor.
Using the Microchip development tools to program the WiFire board will cause the boot loader to be erased. To
use the board with the MPIDE again, it is necessary to program the boot loader back onto the board. The boot
loader HEX file can be found at www.digilentinc.com . To reprogram the bootloader, use the Microchip IPE which
comes with the MPLAB X tool set. The bootloader cannot be easily reprogrammed directly with the MPLAB X IDE.
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