Diff: MCP23S17.cpp

Revision:

0:574e155464d5

--- /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);
+}
+