Diff: MCP23017.h

Revision:

0:a6a5d942b58f

Child:

1:d54d7002bae2

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MCP23017.h	Sun Nov 28 20:41:49 2010 +0000
@@ -0,0 +1,135 @@
+/*  MCP23017 library for Arduino
+    Copyright (C) 2009 David Pye    <davidmpye@gmail.com
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include    "mbed.h"
+
+#ifndef     MBED_MCP23017_H
+#define     MBED_MCP23017_H
+
+//
+// Register defines from data sheet - we set IOCON.BANK to 0
+// as it is easier to manage the registers sequentially.
+//
+#define     IODIR       0x00
+#define     IPOL        0x02
+#define     GPINTEN     0x04
+#define     DEFVAL      0x06
+#define     INTCON      0x08
+#define     IOCON       0x0A
+#define     GPPU        0x0C
+#define     INTF        0x0E
+#define     INTCAP      0x10
+#define     GPIO        0x12
+#define     OLAT        0x14
+
+#define     I2C_BASE_ADDRESS    0x40
+
+#define     DIR_OUTPUT      0
+#define     DIR_INPUT       1
+
+class MCP23017 {
+public:
+    /** Constructor for the MCP23017 connected to specified I2C pins at a specific address
+     *
+     * 16-bit I/O expander with I2C interface
+     *
+     * @param   sda         I2C data pin
+     * @param   scl         I2C clock pin
+     * @param   i2cAddress  I2C address
+     */
+    MCP23017(PinName sda, PinName scl, int i2cAddress);
+
+    /** Reset MCP23017 device to its power-on state
+     */    
+    void reset(void);
+
+    /** Write a 0/1 value to an output bit
+     *
+     * @param   value         0 or 1
+     * @param   bit_number    bit number range 0 --> 15
+     */   
+    void write_bit(int value, int bit_number);
+      
+    /** Write a 0/1 value to an output bit
+     *
+     * @param   data    16-bit data value
+     * @param   mask    16-bit mask value
+     */       
+    void write_mask(unsigned short data, unsigned short mask);
+
+    /** Read a 0/1 value from an input bit
+     *
+     * @param   bit_number    bit number range 0 --> 15
+     * @return                0/1 value read
+     */       
+    int  read_bit(int bit_number);
+    
+    /** Read a 0/1 value from an input bit
+     *
+     * @param   mask    16-bit mask value
+     * @return          16-bit data with mask applied
+     */     
+    int  read_mask(unsigned short mask);
+
+    /** Configure an MCP23017 device
+     *
+     * @param   dir_config         data direction value (1 = input, 0 = output)
+     * @param   pullup_config      100k pullup value (1 = enabled, 0 = disabled)
+     * @param   polarity_config    polarity value (1 = flip, 0 = normal)
+     */           
+    void config(unsigned short dir_config, unsigned short pullup_config, unsigned short polarity_config);
+
+
+/*******************************************************************************
+ * pinmode
+ * Set units to sequential, bank0 mode
+ */  
+
+    void pinMode(int pin, int mode);
+    void digitalWrite(int pin, int val);
+    int  digitalRead(int pin);
+
+// These provide a more advanced mapping of the chip functionality
+// See the data sheet for more information on what they do
+
+//Returns a word with the current pin states (ie contents of the GPIO register)
+    unsigned short digitalWordRead();
+// Allows you to write a word to the GPIO register
+    void digitalWordWrite(unsigned short w);
+// Sets up the polarity mask that the MCP23017 supports
+// if set to 1, it will flip the actual pin value.
+    void inputPolarityMask(unsigned short mask);
+//Sets which pins are inputs or outputs (1 = input, 0 = output) NB Opposite to arduino's
+//definition for these
+    void inputOutputMask(unsigned short mask);
+// Allows enabling of the internal 100k pullup resisters (1 = enabled, 0 = disabled)
+    void internalPullupMask(unsigned short mask);
+
+    int read(void);
+    void write(int data);
+    void writeRegister(int regAddress, unsigned char  val);
+    void writeRegister(int regAddress, unsigned short val);
+    int  readRegister(int regAddress);
+
+protected:
+    I2C     _i2c;
+    int     MCP23017_i2cAddress;                        // physical I2C address
+    unsigned short   shadow_GPIO, shadow_IODIR, shadow_GPPU, shadow_IPOL;     // Cached copies of the register values
+    
+};
+
+#endif
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