sshahryiar
Joined: 05 May 2010
Posts: 94
Location: Dhaka, Bangladesh
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| MCP23S17 16 Bit SPI IO Expander Driver |
 Posted: Wed Oct 02, 2013 10:13 am |
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MCP23S17.h
| Code: |
#use SPI (MASTER, DO = PIN_B1, DI = PIN_B3, CLK = PIN_B0, BITS = 8, Mode = 0)
#define IO_DEVICE_ADDRESS_WRITE 0x40
#define IO_DEVICE_ADDRESS_READ 0x41
#define IODIRA 0x00 //Data Direction Register for PORTA
#define IODIRB 0x01 //Data Direction Register for PORTB
#define IPOLA 0x02 //Input Polarity Register for PORTA
#define IPOLB 0x03 //Input Polarity Register for PORTB
#define GPINTENA 0x04 //Interrupt-on-change enable Register for PORTA
#define GPINTENB 0x05 //Interrupt-on-change enable Register for PORTB
#define DEFVALA 0x06 //Default Value Register for PORTA
#define DEFVALB 0x07 //Default Value Register for PORTB
#define INTCONA 0x08 //Interrupt-on-change control Register for PORTA
#define INTCONB 0x09 //Interrupt-on-change control Register for PORTB
#define IOCON 0x0A //Configuration register for device
#define GPPUA 0x0C //100kOhm pullup resistor register for PORTA (sets pin to input when set)
#define GPPUB 0x0D //100kOhm pullup resistor register for PORTB (sets pin to input when set)
#define INTFA 0x0E //Interrupt flag Register for PORTA
#define INTFB 0x0F //Interrupt flag Register for PORTB
#define INTCAPA 0x10 //Interrupt captured value Register for PORTA
#define INTCAPB 0x11 //Interrupt captured value Register for PORTB
#define GPIOA 0x12 //General purpose I/O Register for PORTA
#define GPIOB 0x13 //General purpose I/O Register for PORTB
#define OLATA 0x14 //Output latch Register for PORTA
#define OLATB 0x15 //Output latch Register for PORTB
#define CS pin_B2
void setup_MCP23S17();
void MCP23S17_write(unsigned char address, unsigned char value);
unsigned char MCP23S17_read(unsigned char address);
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MCP23S17.c
| Code: |
#include "MCP23S17.h"
void setup_MCP23S17()
{
MCP23S17_write(IOCON, 0x18);
MCP23S17_write(IODIRA, 0x00);
MCP23S17_write(IODIRB, 0xFF);
MCP23S17_write(GPPUA, 0x00);
MCP23S17_write(GPPUB, 0xFF);
MCP23S17_write(IPOLA, 0xFF);
MCP23S17_write(IPOLB, 0x00);
}
void MCP23S17_write(unsigned char address, unsigned char value)
{
output_low(CS);
spi_xfer(IO_DEVICE_ADDRESS_WRITE);
spi_xfer(address);
spi_xfer(value);
output_high(CS);
}
unsigned char MCP23S17_read(unsigned char address)
{
unsigned char received_data = 0;
output_low(CS);
spi_xfer(IO_DEVICE_ADDRESS_READ);
spi_xfer(address);
received_data = spi_xfer(0);
output_high(CS);
return received_data;
}
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Example
| Code: |
#include <10F200.h>
#fuses PROTECT, NOWDT, NOMCLR
#use delay (clock = 4MHz)
#include "MCP23S17.c"
void setup();
void main()
{
unsigned char in = 0;
setup();
while(TRUE)
{
in = MCP23S17_read(GPIOB);
MCP23S17_write(OLATA, in);
}
}
void setup()
{
setup_MCP23S17();
}
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SShahryiar |
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