User manual

GPIO Expander Keypad and LCD Demo Board User’s Guide
DS51636A-page 8 © 2006 Microchip Technology Inc.
2.3 GETTING STARTED
The GPIO Expander Keypad and LCD Demo Board is a fully functional, assembled and
tested board for demonstrating the MCP23008 and MCP23017 (I
2
C interface) and
MCP23S08 and MCP23S17 (SPI interface) general purpose I/O expanders. The
following describes the basic setup and operation (see Figure 2-1):
1. Either connect a 9V power supply into the power jack (J2) or connect a 5 V power
supply to the V
DD
and GND test points.
2. The green power LED will illuminate.
3. The LCD will display the startup splash screen.
4. The appropriate LEDs (I
2
C or SPI) will illuminate to indicate the current serial
mode.
5. Pressing buttons:
- 0 - 9, #, *: will be reflected on the LCD
- M: switches modes (I
2
C and SPI) to communicate with the MCP23X17 and
MCP23X08; B: backspace; R: carriage return, and screen clear (2nd
press); S: space
FIGURE 2-1: BOARD LAYOUT
PIC18F2550
USB
ICSP
EXT
M
LED
MCP23017
MCP23S17
MCP23008
MCP23S08
* 0 # S
1 2 3 R
4 5 6 B
7 8 9 M
2 X 16 LCD
16-bit HEADER
8-bit HEADER
LED
LED
LED
I2C/SPI
9V
USB
GND
+5V
Not Populated
GPIO Expander
Keypad/LCD Demo