chipKIT™ WF32™ Board Reference Manual
Copyright Digilent, Inc. All rights reserved.
Other product and company names mentioned may be trademarks of their respective owners.
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24
12
User LEDs
27
J2- USB- UART Handshaking Signals
13
JP6,7- SPI Master/ SPI Slave Select
28
USB connector for USB Serial Converter
14
J10- SPI Connector
29
Serial Communication LEDs
15
JP10- USB Host or OTG Select
2
MPIDE and USB Serial Communications
The WF32 board is designed to be used with MPIDE. The MPIDE development platform was created by modifying
the Arduino IDE. It is backwards-compatible with the Arduino IDE. Links for where to obtain the MPIDE installation
files and instructions for installing MPIDE can be found at www.chipkit.net/started.
The MPIDE uses a serial communications port to communicate with a boot loader running on the WF32 board. The
serial port on the WF32 board is implemented using an FTDI FT232RQ USB serial converter. Before attempting to
use the MPIDE to communicate with the WF32, the appropriate USB device driver must be installed.
The WF32 board uses a standard mini-USB connector. Generally, a USB A to mini-B cable is used for connection to
a USB port on the PC.
When the MPIDE needs to communicate with the WF32 board, the board is reset and starts running the boot
loader. The MPIDE then establishes communications with the boot loader and uploads the program to the board.
When the MPIDE opens the serial communications connection on the PC, the DTR pin on the FT232RQ chip is
driven low. This pin is coupled through a capacitor to the MCLR pin on the PIC32 microcontroller. Driving the MCLR
line low resets the microcontroller, which restarts the execution with the boot loader.
This automatic reset action (when the serial communications connection is opened) can be disabled. To disable
this operation, there is a jumper labeled JP1, which can be disconnected. JP1 is normally shorted, but if the
shorting block is removed, the automatic reset operation will be disabled.
Two red LEDs (LD1 and LD2) will blink when data is being sent or received between the WF32 and the PC over the
serial connection.
The header connector J2 provides access to the other serial handshaking signals provided by the FT232RQ.
Connector J2 is not loaded at the factory and can be installed by the user to access these signals.
3
Power Supply
The WF32 is designed to be powered via USB (J1), from an external power supply (J14 or J17), or from the USB OTG
receptacle (J12). Jumper block J15 is used to select which power supply is used. The power supply voltage selected
by J15 is applied to the unregulated power bus, VU.
In order to operate the WF32 as a USB device powered from the USB serial interface, connector J1, place a
shorting block in the UART position of jumper block J15. To operate the WF32 from an external power supply,