Diff: MCP23017.cpp

Revision:

22:c024b20a0e2d

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MCP23017.cpp	Wed Jun 13 09:06:55 2018 +0000
@@ -0,0 +1,169 @@
+/* MCP23017 - drive the Microchip MCP23017 16-bit Port Extender using I2C
+* Copyright (c) 2010 Wim Huiskamp, Romilly Cocking (original version for SPI)
+*
+* Released under the MIT License: http://mbed.org/license/mit
+*
+* version 0.2 Initial Release
+* version 0.3 Cleaned up
+* version 0.4 Fixed problem with _read method
+* version 0.5 Added support for 'Banked' access to registers
+*/
+
+#include "mbed.h"
+#include "MCP23017.h"
+
+/** Create an MCP23017 object connected to the specified I2C object and using the specified deviceAddress
+*
+* @param I2C &i2c the I2C port to connect to 
+* @param char deviceAddress the address of the MCP23017
+*/
+MCP23017::MCP23017(I2C &i2c, char deviceAddress) : _i2c(i2c) {
+    _writeOpcode = deviceAddress & 0xFE; // low order bit = 0 for write
+    _readOpcode  = deviceAddress | 0x01; // low order bit = 1 for read
+    _init();
+}
+
+/** Read from specified MCP23017 register
+*
+* @param char address the internal registeraddress of the MCP23017
+* @returns data from register 
+*/
+char MCP23017::_read(char address) {
+    char data[2];
+
+    data[0] = address;
+    _i2c.write(_writeOpcode, data, 1);     // Select Register for reading
+    _i2c.read(_readOpcode, data, 1);       // Read from selected Register
+    
+    return data[0];
+}
+
+
+/** Write to specified MCP23017 register
+*
+* @param char address the internal registeraddress of the MCP23017
+*/
+void MCP23017::_write(char address, char byte) {
+    char data[2];
+
+    data[0] = address;
+    data[1] = byte;
+    _i2c.write(_writeOpcode, data, 2);    // Write data to selected Register
+}
+
+
+/** Init MCP23017
+*
+* @param
+* @returns 
+*/
+void MCP23017::_init() {
+  
+  _bankMode = NOT_BNK;  // This may not be true after software reset without hardware reset !!!
+  
+  _write(IOCON_AB[_bankMode][PORT_A], (IOCON_BYTE_MODE | IOCON_HAEN )); // Hardware addressing on, no-autoincrement, 16 bit mode (operations toggle between A and B registers)
+
+}
+
+/** Set I/O direction of specified MCP23017 Port
+*
+* @param Port Port address (Port_A or Port_B)
+* @param char direction pin direction (0 = output, 1 = input)
+*/
+void MCP23017::direction(Port port, char direction) {
+    _write(IODIR_AB[_bankMode][port], direction);
+}
+
+/** Set Pull-Up Resistors on specified MCP23017 Port
+*
+* @param Port Port address (Port_A or Port_B)
+* @param char offOrOn per pin (0 = off, 1 = on)
+*/
+void MCP23017::configurePullUps(Port port, char offOrOn) {
+  
+  _write(GPPU_AB[_bankMode][port], offOrOn); 
+}
+
+/** Configere the Banked or Non-Banked mode
+*
+* @param Bank bankMode
+* @param char offOrOn per pin (0 = off, 1 = on)
+*/
+void MCP23017::configureBanked(Bank bankMode) {
+
+    if (bankMode == NOT_BNK) {
+      // Non-Banked sequential registers (default POR)
+      // Hardware addressing on, , no-autoincrement, 16 bit mode (operations do toggle between A and B registers)          
+      _write(IOCON_AB[_bankMode][PORT_A], (IOCON_BYTE_MODE | IOCON_HAEN ));
+      _bankMode = NOT_BNK;
+    }  
+    else {
+      // Banked registers
+      // Hardware addressing on, no-autoincrement, 8 bit mode           
+      _write(IOCON_AB[_bankMode][PORT_A], (IOCON_BANK | IOCON_BYTE_MODE | IOCON_HAEN ));
+      _bankMode = BNK;
+    }
+}
+
+
+void MCP23017::interruptEnable(Port port, char interruptsEnabledMask) {
+  
+  _write(GPINTEN_AB[_bankMode][port], interruptsEnabledMask);    
+   
+}
+
+void MCP23017::mirrorInterrupts(bool mirror) {
+  char iocon = _read(IOCON_AB[_bankMode][PORT_A]);
+
+  if (mirror) {
+    iocon = iocon | INTERRUPT_MIRROR_BIT;
+  }
+  else {
+    iocon = iocon & ~INTERRUPT_MIRROR_BIT;
+  }
+
+  _write(IOCON_AB[_bankMode][PORT_A], iocon);
+
+}
+
+void  MCP23017::interruptPolarity(Polarity polarity) {
+    char iocon = _read(IOCON_AB[_bankMode][PORT_A]);
+    
+    if (polarity == ACTIVE_LOW) {
+        iocon = iocon & ~INTERRUPT_POLARITY_BIT;
+    } else {
+        iocon = iocon | INTERRUPT_POLARITY_BIT;
+    }
+    _write(IOCON_AB[_bankMode][PORT_A], iocon);
+}
+
+void MCP23017::defaultValue(Port port, char valuesToCompare) {
+    
+  _write(DEFVAL_AB[_bankMode][port], valuesToCompare);
+    
+}
+
+void MCP23017::interruptControl(Port port, char interruptControlBits) {
+    
+  _write(INTCON_AB[_bankMode][port], interruptControlBits);
+    
+}
+
+/** Write to specified MCP23017 Port
+*
+* @param Port Port address (Port_A or Port_B)
+* @param char byte data to write
+*/
+void MCP23017::write(Port port, char byte) {
+    _write(OLAT_AB[_bankMode][port], byte);
+}
+    
+/** Read from specified MCP23017 Port
+*
+* @param Port Port address (Port_A or Port_B)
+* @returns data from Port 
+*/
+char MCP23017::read(Port port) {
+    return _read(GPIO_AB[_bankMode][port]);
+}
+