Microchip Technology DV164136 User Manual
© 2008 Microchip Technology Inc.
DS51721B-page 27
PICDEM™ PIC18 EXPLORER
DEMONSTRATION BOARD
USER’S GUIDE
Appendix A. Hardware Details
A.1
HARDWARE ELEMENTS
A.1.1
Processor Sockets
The PICDEM PIC18 Explorer Demonstration Board can be populated with 64 and
80-pin devices. Using a Plug-In Module (PIM), the board also can support 28, 44, 64
and 80-pin devices.
80-pin devices. Using a Plug-In Module (PIM), the board also can support 28, 44, 64
and 80-pin devices.
For a list of available PIMs, go to the Microchip web site at http://microchip.com.
A.1.2
Display
Eight LEDs are connected to PORTD of the PICDEM PIC18 Explorer Demonstration
Board. The PORTD pins are set high to light the LEDs.
Board. The PORTD pins are set high to light the LEDs.
These LEDs may be disconnected by removing jumper JP1.
One LED (D9) lights to indicate when the board has power.
A.1.3
Power Supply
The PIC18 Explorer Board does not come with a power supply. It can be powered, via
J1, with an unregulated DC supply of 9V to 15V. The preferred supply is 9V.
J1, with an unregulated DC supply of 9V to 15V. The preferred supply is 9V.
For default functionality, a power supply with a current capability of 250 mA is sufficient.
Since the board can serve as a modular development platform connecting to multiple
expansion boards, voltage regulators (Q1 and Q2) are used. Their maximum current
capability is 800 mA. This current capacity may require a power supply of up to 1.6A.
Because the regulators do not have heat sinks, long-term operation at such loads is not
recommended.
expansion boards, voltage regulators (Q1 and Q2) are used. Their maximum current
capability is 800 mA. This current capacity may require a power supply of up to 1.6A.
Because the regulators do not have heat sinks, long-term operation at such loads is not
recommended.
When the board is powered, LED D9 is on, indicating the presence of V_VAR.
If an external supply is needed, Microchip’s 9V, 750 mA power supply (part number
AC162039) can be used.
AC162039) can be used.
A.1.4
RS-232 Serial Port
An RS-232, level-shifting integrated circuit has been provided with all the necessary
hardware to support the connection of an RS-232 host through the DB9 connector. The
port can be connected to a PC using a straight-through cable.
hardware to support the connection of an RS-232 host through the DB9 connector. The
port can be connected to a PC using a straight-through cable.
The PIC18 receive and transmit pins are tied to the receive and transmit lines of the
MAX3232 transceiver through jumper J13. That jumper can direct where the receive
and transmit pins of the PIC18 are connected, either to:
MAX3232 transceiver through jumper J13. That jumper can direct where the receive
and transmit pins of the PIC18 are connected, either to:
• The PIC18LF2450 which does the RS-232 to USB communication
• The MAX3232 transceiver
Note:
Do not attempt to power the PICDEM PIC18 Explorer Demonstration Board
using the MPLAB ICD 2 module. That module is not designed to be a USB
bus power source.
using the MPLAB ICD 2 module. That module is not designed to be a USB
bus power source.
Note:
For details on this connection, see Section 2.5 “Connecting to Host PC
for RS-232 Communication”.
for RS-232 Communication”.