Revision 0:574e155464d5, committed 2015-01-28

Comitter:

sheldonfernandes2404

Date:

Wed Jan 28 04:08:50 2015 +0000

Commit message:

1

Changed in this revision

diff -r 000000000000 -r 574e155464d5 MCP23S17.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MCP23S17.cpp	Wed Jan 28 04:08:50 2015 +0000
@@ -0,0 +1,94 @@
+/* MCP23S17 - drive the Microchip MCP23S17 16-bit Port Extender using SPI
+* Copyright (c) 2010 Romilly Cocking
+* Released under the MIT License: http://mbed.org/license/mit
+*
+* version 0.4
+*/
+
+#include "mbed.h"
+#include "MCP23S17.h"
+
+MCP23S17::MCP23S17(SPI& spi, PinName ncs, char writeOpcode) : _spi(spi), _ncs(ncs) {
+    _writeOpcode = writeOpcode;
+    _readOpcode = _writeOpcode | 1; // low order bit = 1 for read
+    _init();
+}
+
+char MCP23S17::_read(char address) {
+    _ncs = 0;
+    _spi.write(_readOpcode);
+    _spi.write(address);
+    char result = _spi.write(0);
+    _ncs = 1;
+    return result;
+}
+
+char MCP23S17::_read(Port port, char address) {
+    return _read(address + (char) port);
+}
+
+void MCP23S17::_write(char address, char data) {
+    _ncs = 0;
+    _spi.write(_writeOpcode);
+    _spi.write(address);
+    _spi.write(data);
+    _ncs = 1;
+}
+
+void  MCP23S17::_write(Port port, char address, char data) {
+    _write(address + (char) port, data);
+}
+
+void MCP23S17::_init() {
+    _write(IOCON, (IOCON_BYTE_MODE | IOCON_HAEN )); // Hardware addressing on, operations toggle between A and B registers
+}
+
+void MCP23S17::direction(Port port, char direction) {
+    _write(port, IODIRA, direction);
+}
+
+void MCP23S17::configurePullUps(Port port, char offOrOn) {
+    _write(port, GPPUA, offOrOn);
+}
+
+void MCP23S17::interruptEnable(Port port, char interruptsEnabledMask) {
+    _write(port, GPINTENA, interruptsEnabledMask);
+}
+
+void MCP23S17::mirrorInterrupts(bool mirror) {
+ char iocon = _read(IOCON);
+    if (mirror) {
+        iocon = iocon | INTERRUPT_MIRROR_BIT;
+    } else {
+        iocon = iocon & ~INTERRUPT_MIRROR_BIT;
+    }
+    _write(IOCON, iocon);
+
+}
+
+void  MCP23S17::interruptPolarity(Polarity polarity) {
+    char iocon = _read(IOCON);
+    if (polarity == ACTIVE_LOW) {
+        iocon = iocon & ~INTERRUPT_POLARITY_BIT;
+    } else {
+        iocon = iocon | INTERRUPT_POLARITY_BIT;
+    }
+    _write(IOCON, iocon);
+}
+
+void MCP23S17::defaultValue(Port port, char valuesToCompare) {
+    _write(port, DEFVALA, valuesToCompare);
+}
+
+void MCP23S17::interruptControl(Port port, char interruptContolBits) {
+    _write(port, INTCONA, interruptContolBits);
+}
+
+void MCP23S17::write(Port port, char byte) {
+    _write(port, OLATA, byte);
+}
+
+char MCP23S17::read(Port port) {
+    return _read(port, GPIOA);
+}
+

diff -r 000000000000 -r 574e155464d5 MCP23S17.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MCP23S17.h	Wed Jan 28 04:08:50 2015 +0000
@@ -0,0 +1,59 @@
+/* MCP23S17 - drive the Microchip MCP23S17 16-bit Port Extender using SPI
+* Copyright (c) 2010 Romilly Cocking
+* Released under the MIT License: http://mbed.org/license/mit
+*
+* version 0.4
+*/
+#include "mbed.h"
+
+#ifndef  MCP23S17_H
+#define  MCP23S17_H
+
+#define INTERRUPT_POLARITY_BIT 0x02
+#define INTERRUPT_MIRROR_BIT   0x40
+
+// all register addresses assume IOCON.BANK = 0 (POR default)
+
+#define IODIRA   0x00
+#define GPINTENA 0x04
+#define DEFVALA  0x06
+#define INTCONA  0x08
+#define IOCON    0x0A
+#define GPPUA    0x0C
+#define GPIOA    0x12
+#define OLATA    0x14
+
+// Control settings
+
+#define IOCON_BANK  0x80 // Banked registers
+#define IOCON_BYTE_MODE 0x20 // Disables sequential operation. If bank = 0, operations toggle between A and B registers
+#define IOCON_HAEN  0x08 // Hardware address enable
+
+enum Polarity { ACTIVE_LOW , ACTIVE_HIGH };
+enum Port { PORT_A, PORT_B };
+
+class MCP23S17 {
+public:
+    MCP23S17(SPI& spi, PinName ncs, char writeOpcode);
+    void direction(Port port, char direction);
+    void configurePullUps(Port port, char offOrOn);
+    void interruptEnable(Port port, char interruptsEnabledMask);
+    void interruptPolarity(Polarity polarity);
+    void mirrorInterrupts(bool mirror);
+    void defaultValue(Port port, char valuesToCompare);
+    void interruptControl(Port port, char interruptContolBits);
+    char read(Port port);
+    void write(Port port, char byte);
+protected:
+    SPI& _spi;
+    DigitalOut _ncs;
+    void _init();
+    void _write(Port port, char address, char data);
+    void _write(char address, char data);
+    char _read(Port port, char address);
+    char _read(char address);
+    char _readOpcode;
+    char _writeOpcode;
+};
+
+#endif
\ No newline at end of file

diff -r 000000000000 -r 574e155464d5 main.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Wed Jan 28 04:08:50 2015 +0000
@@ -0,0 +1,29 @@
+#include "mbed.h"
+#include "MCP23S17.h"
+
+//------------------------------//
+SPI spi(p5, p6, p7);
+char Opcode1 = 0x40;
+char Opcode2 = 0x42;
+MCP23S17 chip1 = MCP23S17(spi, p20, Opcode1);
+MCP23S17 chip2 = MCP23S17(spi, p20, Opcode2);
+//-------------------------------//
+
+int main()
+{
+
+    chip1.direction(PORT_A, 0x00); //output
+    chip2.direction(PORT_B, 0xFF); //input
+
+    while (1) {
+
+        if(chip2.read(PORT_B)) {
+            chip1.write(PORT_A, 0x00);
+        } else {
+            chip1.write(PORT_A, 0xAA);
+        }
+
+
+    }
+
+}
\ No newline at end of file

diff -r 000000000000 -r 574e155464d5 mbed.bld
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Wed Jan 28 04:08:50 2015 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/4fc01daae5a5
\ No newline at end of file