Digilent 410-295P-KIT User Manual

Page 26

ChipKIT Pro MX4 Reference Manual

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Page 26 of 37

Pin 20 on the PIC32MX460 microcontroller has multiple functions. It functions as the
VBUSON control pin when acting as a USB host. It can be used as an analog input for the
A/D converter or one of the analog comparators. It can also be used as a pin change
interrupt input or as a general digital i/o. This jumper is used to route pin 20 to one of
three places on the board:
Place a shorting block in the upper, VBUSON, position when acting as a USB host to control
the USB power supplied to the connected device.
Place a shorting block in the middle, DAC, position to connect the output of the MCP4725
digital to analog converter to pin 20. This allows the use of the DAC output as an input to
analog comparator #1.
Place a shorting block in the lower, JJ-8, position to connect pin 20 to Pmod connector JJ,
pin 8. This allows access to pin 20 from this Pmod connector.

J17

USB host connector
This is a standard USB type A connector. This is used to connect a USB device when the
ChipKIT Pro MX4 is being used as a USB host.

J18

External power connector
This is a two pin screw terminal connector that can be used to supply external power to
the board.

J19

Auxiliary Power Out
This connector provides access to the unregulated power bus BRD_VU and GND. It can be
used to distribute power to other boards from the ChipKIT Pro MX4.

JP1

Connect VS bus to BRD_VU bus
This jumper is used to connect the VS bus to the BRD_VU bus. The VS bus provides power
to the servo connectors, S1-S8. The BRD_VU bus is the main board power bus. Install a
shorting block on this jumper to have the servo power bus powered from the main power
bus. Remove the shorting block from this jumper to separate the two power busses. When
using a separate servo power bus, the VS bus is powered from screw terminal connector
J5.

JP2

VS bus voltage monitor
This jumper is used to enable monitoring of the VS bus voltage. When a shorting block is
installed on this jumper, the VS bus is connected via a voltage divider to analog input AN9.
This can be used, for example, to monitor the state of a battery supply being used to
power servos.

JP3

Connector JB pin 7 signal select
This jumper is used to route either signal SCL1/INT3/RA14 or PMALL/AN15/CN12/RB15 to
the pin 7 position of Pmod connector JB. The jumper is normally in the RB15 position. This
allows connector the PIC32 Parallel Master Port to be used with connector JB. Place the
jumper in the INT3 position when using JB to access an SPI device that requires an
interrupt on pin 7.

JP4

BRD_VU bus voltage monitor
This jumper is used to enable monitoring of the BRD_VU bus voltage. When a shorting
block is installed on this jumper, the BRD_VU bus is connected via a voltage divider to
analog input AN8. This can be used, for example, to monitor the state of a battery supply
being used to power the board.

JP5

USB over-current detect
This jumper is used to enable monitoring of the over-current detect capability of the USB
bus power switch, IC6. When a shorting block is installed on this jumper, the over-current
output pin of IC6 is connected to the INT2/RE9 pin of the PIC32MX460 microcontroller.

JP6

USB host power select
This jumper is used to select which host connector is powered when host power is
enabled. Place the shorting block in the “OTG” position to supply power to the USB OTG
Connector, J15. Place the shorting block in the “HOST” position to supply power to the USB
Host Connector, J17.