Microchip Technology DM300019 Data Sheet
dsPICDEM™ 80-Pin Starter Development Board User’s Guide
DS51584B-page 34
© 2006 Microchip Technology Inc.
4.1.1
RS-232 Serial Port
One RS-232 serial communication channel is provided on the board. This channel is
labeled J1. The dsPIC DSC or PIC24 MCU UART channel 1 U1RX and U1TX pins are
connected to an RS-232 level shifting MAX3232CD (U3), as shown in Figure A-3. The
serial port is configured as DCE and can be connected to a PC using a straight through
cable.
labeled J1. The dsPIC DSC or PIC24 MCU UART channel 1 U1RX and U1TX pins are
connected to an RS-232 level shifting MAX3232CD (U3), as shown in Figure A-3. The
serial port is configured as DCE and can be connected to a PC using a straight through
cable.
4.1.2
Analog Potentiometer
An analog potentiometer (R13) is connected to analog channel AN2 on the dsPIC DSC
or PIC24 MCU device. The voltage output range for the potentiometer is 0-5 VDC. The
voltage source is provided by the +5VAN regulator, as shown in Figure A-6.
or PIC24 MCU device. The voltage output range for the potentiometer is 0-5 VDC. The
voltage source is provided by the +5VAN regulator, as shown in Figure A-6.
4.1.3
Push Button Switches
Two push button switches (S1 and S2) are connected to port pin RA12 and RA13,
respectively, on the dsPIC DSC or PIC24 MCU device, as shown in Figure A-3. The
signal lines are normally pulled up to V
respectively, on the dsPIC DSC or PIC24 MCU device, as shown in Figure A-3. The
signal lines are normally pulled up to V
DD
through 4.7K resistors. Pressing the switch
shorts the line to ground. Port pins RA12 and RA13 are configured as input pins.
4.1.4
LED Indicators
Four LED indicators (D2 to D5) are connected to port pins RD4 to RD7, respectively,
on the dsPIC DSC or PIC24 MCU device. The anode of each LED is tied to V
on the dsPIC DSC or PIC24 MCU device. The anode of each LED is tied to V
DD
through a 470 ohm resistor, as shown in Figure A-3. The cathodes are shorted and
connected to GND by an activation header (J4). The LEDs are labeled RD4 through
RD7 on the board to correspond to their respective port pins.
connected to GND by an activation header (J4). The LEDs are labeled RD4 through
RD7 on the board to correspond to their respective port pins.
4.1.5
Digital Potentiometer
A single channel digital potentiometer (U2) is provided on the development board. The
MCP41010_SO150 digital potentiometer is controlled by the SPI2 communication
channel on the dsPIC DSC or PIC24 MCU device. The output of the digital
potentiometer is applied to a 2nd-order, low-pass filter, with a cutoff frequency of
approximately 4 kHz. The output of the LP filter is connected to the LINE OUT pin of
J9, as shown in Figure A-6.
MCP41010_SO150 digital potentiometer is controlled by the SPI2 communication
channel on the dsPIC DSC or PIC24 MCU device. The output of the digital
potentiometer is applied to a 2nd-order, low-pass filter, with a cutoff frequency of
approximately 4 kHz. The output of the LP filter is connected to the LINE OUT pin of
J9, as shown in Figure A-6.
4.1.6
Low-Pass Filter
A Microchip MCP6022_SO8 Operational Amplifier is configured as a 2nd-order,
low-pass filter for speech or voice input filtering, as shown in Figure A-6. The input to
the filter is at the LINE IN pin of J9.
low-pass filter for speech or voice input filtering, as shown in Figure A-6. The input to
the filter is at the LINE IN pin of J9.
4.1.7
ICD 2 Connector
By way of the modular connector ICD (J3), the MPLAB ICD 2 can be connected for
low-cost programming and debugging of the dsPIC DSC or PIC24 MCU device.
low-cost programming and debugging of the dsPIC DSC or PIC24 MCU device.
4.1.8
Device Header
Header P1 supports the processor adaptor boards. The processor adaptor boards
enable quick change out of the device.
enable quick change out of the device.
4.1.9
I/O Port Header
Header P2 is a two-row header with appropriate labels for I/O ports. This header allows
the user to easily probe appropriate I/O lines.
the user to easily probe appropriate I/O lines.