Diff: MCP23016.cpp

Revision:

0:133b7e09bbe7

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MCP23016.cpp	Tue Jan 19 23:50:23 2016 +0000
@@ -0,0 +1,216 @@
+/*  MCP23016 library
+    Based on MCP23017 library for arduino by 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 "MCP23016.h"
+#include "mbed.h"
+
+union {
+    uint8_t  value8[2];
+    uint16_t value16;
+} tmp_data;
+
+/*-----------------------------------------------------------------------------
+ *
+ */
+MCP23016::MCP23016(PinName sda, PinName scl, int i2cAddress)  : _i2c(sda, scl) {
+    MCP23016_i2cAddress = I2C_BASE_ADDRESS + i2cAddress;
+    reset();                                  // initialise chip to power-on condition
+}
+
+/*-----------------------------------------------------------------------------
+ * reset
+ * Set configuration (IOCON) and direction(IODIR) registers to initial state
+ */
+void MCP23016::reset() {
+//
+// set direction registers to inputs
+//
+    writeRegister(IODIR0, (unsigned short)0xFFFF);
+//
+// set all other registers to zero (last of 10 registers is OLAT)
+//
+    for (int reg_addr = OLAT0 ; reg_addr <= IPOL1 ; reg_addr+=2) {
+        writeRegister(reg_addr, (unsigned short)0x0000);
+    }
+//
+// Set the shadow registers to power-on state
+//
+    shadow_IODIR = 0xFFFF;
+    shadow_GPIO  = 0;
+    shadow_IPOL  = 0;
+}
+
+/*-----------------------------------------------------------------------------
+ * write_bit
+ * Write a 1/0 to a single bit of the 16-bit port
+ */
+void MCP23016::write_bit(int value, int bit_number) {
+    if (value == 0) {
+        shadow_GPIO &= ~(1 << bit_number);
+    } else {
+        shadow_GPIO |= 1 << bit_number;
+    }
+    writeRegister(OLAT0, (unsigned short)shadow_GPIO);
+}
+
+/*-----------------------------------------------------------------------------
+ * Write a combination of bits to the 16-bit port
+ */
+void MCP23016::write_mask(unsigned short data, unsigned short mask) {
+    shadow_GPIO = (shadow_GPIO & ~mask) | data;
+    writeRegister(OLAT0, (unsigned short)shadow_GPIO);
+}
+
+/*-----------------------------------------------------------------------------
+ * read_bit
+ * Read a single bit from the 16-bit port
+ */
+int  MCP23016::read_bit(int bit_number) {
+    shadow_GPIO = readRegister(GP0);
+    return  ((shadow_GPIO >> bit_number) & 0x0001);
+}
+
+/*-----------------------------------------------------------------------------
+ * read_mask
+ */
+int  MCP23016::read_mask(unsigned short mask) {
+    shadow_GPIO = readRegister(GP0);
+    return (shadow_GPIO & mask);
+}
+
+/*-----------------------------------------------------------------------------
+ * Config
+ * set direction and pull-up registers
+ */
+void MCP23016::config(unsigned short dir_config, unsigned short polarity_config) {
+    shadow_IODIR = dir_config;
+    writeRegister(IODIR0, (unsigned short)shadow_IODIR);
+    shadow_IPOL = polarity_config;
+    writeRegister(IPOL0, (unsigned short)shadow_IPOL);
+}
+
+/*-----------------------------------------------------------------------------
+ * writeRegister
+ * write a byte
+ */
+void MCP23016::writeRegister(int regAddress, unsigned char data) {
+    char  buffer[2];
+
+    buffer[0] = regAddress;
+    buffer[1] = data;
+    _i2c.write(MCP23016_i2cAddress, buffer, 2);
+}
+
+/*----------------------------------------------------------------------------
+ * write Register
+ * write two bytes
+ */ 
+void MCP23016::writeRegister(int regAddress, unsigned short data) {
+    char  buffer[3];
+
+    buffer[0] = regAddress;
+    tmp_data.value16 = data;
+    buffer[1] = tmp_data.value8[0];
+    buffer[2] = tmp_data.value8[1];
+
+    _i2c.write(MCP23016_i2cAddress, buffer, 3);
+}
+
+/*-----------------------------------------------------------------------------
+ * readRegister
+ */
+int MCP23016::readRegister(int regAddress) {
+    char buffer[2];
+
+    buffer[0] = regAddress;
+    _i2c.write(MCP23016_i2cAddress, buffer, 1);
+    _i2c.read(MCP23016_i2cAddress, buffer, 2);
+
+    return ((int)(buffer[0] + (buffer[1]<<8)));
+}
+
+/*-----------------------------------------------------------------------------
+ * pinMode
+ */
+void MCP23016::pinMode(int pin, int mode) {
+    if (mode == DIR_INPUT) {
+        shadow_IODIR |= 1 << pin;
+    } else {
+        shadow_IODIR &= ~(1 << pin);
+    }
+    writeRegister(IODIR0, (unsigned short)shadow_IODIR);
+}
+
+/*-----------------------------------------------------------------------------
+ * digitalRead
+ */
+int MCP23016::digitalRead(int pin) {
+    shadow_GPIO = readRegister(GP0);
+    if ( shadow_GPIO & (1 << pin)) {
+        return 1;
+    } else {
+        return 0;
+    }
+}
+
+/*-----------------------------------------------------------------------------
+ * digitalWrite
+ */
+void MCP23016::digitalWrite(int pin, int val) {
+    // This will set the OUTPUT voltage
+    //as appropriate.
+    bool isOutput = !(shadow_IODIR & 1<<pin);
+
+    if (isOutput) {
+        //This is an output pin so just write the value
+        if (val) shadow_GPIO |= 1 << pin;
+        else shadow_GPIO &= ~(1 << pin);
+        writeRegister(OLAT0, (unsigned short)shadow_GPIO);
+    }
+}
+
+/*-----------------------------------------------------------------------------
+ * digitalWordRead
+ */
+unsigned short MCP23016::digitalWordRead() {
+    shadow_GPIO = readRegister(GP0);
+    return shadow_GPIO;
+}
+
+/*-----------------------------------------------------------------------------
+ * digitalWordWrite
+ */
+void MCP23016::digitalWordWrite(unsigned short w) {
+    shadow_GPIO = w;
+    writeRegister(OLAT0, (unsigned short)shadow_GPIO);
+}
+
+/*-----------------------------------------------------------------------------
+ * inputPolarityMask
+ */
+void MCP23016::inputPolarityMask(unsigned short mask) {
+    writeRegister(IPOL0, mask);
+}
+
+/*-----------------------------------------------------------------------------
+ * inputoutputMask
+ */
+void MCP23016::inputOutputMask(unsigned short mask) {
+    shadow_IODIR = mask;
+    writeRegister(IODIR0, (unsigned short)shadow_IODIR);
+}
+