Diff: LM75B.cpp

Revision:

0:557a92280097

Child:

1:3da8df4319e8

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/LM75B.cpp	Wed Jul 31 22:04:57 2013 +0000
@@ -0,0 +1,273 @@
+/* mbed LM75B Library
+ * Copyright (c) 2013 neilt6
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "LM75B.h"
+#include "mbed.h"
+
+LM75B::LM75B(PinName sda, PinName scl, int addr) : _i2c(sda, scl)
+{
+    //Set the internal device address
+    _addr = addr;
+}
+
+LM75B_Power_t LM75B::getPowerMode(void)
+{
+    //Read the 8-bit register value
+    char value = _read8(LM75B_REG_CONF);
+
+    //Return the status of the SHUTDOWN bit
+    if (value & (1 << 0))
+        return LM75B_Power_Shutdown;
+    else
+        return LM75B_Power_Normal;
+}
+
+void LM75B::setPowerMode(LM75B_Power_t mode)
+{
+    //Read the current 8-bit register value
+    char value = _read8(LM75B_REG_CONF);
+
+    //Set or clear the SHUTDOWN bit
+    if (mode == LM75B_Power_Shutdown)
+        value |= (1 << 0);
+    else
+        value &= ~(1 << 0);
+
+    //Write the value back out
+    _write8(LM75B_REG_CONF, value);
+}
+
+LM75B_OS_Mode_t LM75B::getOSMode(void)
+{
+    //Read the 8-bit register value
+    char value = _read8(LM75B_REG_CONF);
+
+    //Return the status of the OS_COMP_INT bit
+    if (value & (1 << 1))
+        return LM75B_OS_Interrupt;
+    else
+        return LM75B_OS_Comparator;
+}
+
+void LM75B::setOSMode(LM75B_OS_Mode_t mode)
+{
+    //Read the current 8-bit register value
+    char value = _read8(LM75B_REG_CONF);
+
+    //Set or clear the OS_COMP_INT bit
+    if (mode == LM75B_OS_Interrupt)
+        value |= (1 << 1);
+    else
+        value &= ~(1 << 1);
+
+    //Write the value back out
+    _write8(LM75B_REG_CONF, value);
+}
+
+LM75B_OS_Polarity_t LM75B::getOSPolarity(void)
+{
+    //Read the 8-bit register value
+    char value = _read8(LM75B_REG_CONF);
+
+    //Return the status of the OS_POL bit
+    if (value & (1 << 2))
+        return LM75B_OS_ActiveHigh;
+    else
+        return LM75B_OS_ActiveLow;
+}
+
+void LM75B::setOSPolarity(LM75B_OS_Polarity_t polarity)
+{
+    //Read the current 8-bit register value
+    char value = _read8(LM75B_REG_CONF);
+
+    //Set or clear the OS_POL bit
+    if (polarity == LM75B_OS_ActiveHigh)
+        value |= (1 << 2);
+    else
+        value &= ~(1 << 2);
+
+    //Write the value back out
+    _write8(LM75B_REG_CONF, value);
+}
+
+LM75B_OS_FaultQueue_t LM75B::getOSFaultQueue(void)
+{
+    //Read the 8-bit register value
+    char value = _read8(LM75B_REG_CONF);
+
+    //Return the status of the OS_F_QUE bits
+    if ((value & (1 << 3)) && (value & (1 << 4)))
+        return LM75B_OS_FaultQueue_6;
+    else if (!(value & (1 << 3)) && (value & (1 << 4)))
+        return LM75B_OS_FaultQueue_4;
+    else if ((value & (1 << 3)) && !(value & (1 << 4)))
+        return LM75B_OS_FaultQueue_2;
+    else
+        return LM75B_OS_FaultQueue_1;
+}
+
+void LM75B::setOSFaultQueue(LM75B_OS_FaultQueue_t queue)
+{
+    //Read the current 8-bit register value
+    char value = _read8(LM75B_REG_CONF);
+
+    //Clear the old OS_F_QUE bits
+    value &= ~(3 << 3);
+
+    //Set the new OS_F_QUE bits
+    if (queue == LM75B_OS_FaultQueue_2)
+        value |= (1 << 3);
+    else if (queue == LM75B_OS_FaultQueue_4)
+        value |= (2 << 3);
+    else if (queue == LM75B_OS_FaultQueue_6)
+        value |= (3 << 3);
+
+    //Write the value back out
+    _write8(LM75B_REG_CONF, value);
+}
+
+float LM75B::getAlertTemp(void)
+{
+    //Use the 9-bit helper to read the TOS register
+    return _readTempHelper(LM75B_REG_TOS);
+}
+
+void LM75B::setAlertTemp(float temp)
+{
+    //Use the 9-bit helper to write to the TOS register
+    return _writeTempHelper(LM75B_REG_TOS, temp);
+}
+
+float LM75B::getAlertHyst(void)
+{
+    //Use the 9-bit helper to read the THYST register
+    return _readTempHelper(LM75B_REG_THYST);
+}
+
+void LM75B::setAlertHyst(float temp)
+{
+    //Use the 9-bit helper to write to the THYST register
+    return _writeTempHelper(LM75B_REG_THYST, temp);
+}
+
+float LM75B::getTemp(void)
+{
+    //Signed return value
+    short value;
+
+    //Read the 11-bit raw temperature value
+    value = _read16(LM75B_REG_TEMP) >> 5;
+
+    //Sign extend negative numbers
+    if (value & (1 << 10))
+        value |= 0xFC00;
+
+    //Return the temperature in °C
+    return value * 0.125;
+}
+
+char LM75B::_read8(char reg)
+{
+    //Select the register
+    _i2c.write(_addr, &reg, 1);
+
+    //Read the 8-bit register
+    _i2c.read(_addr, &reg, 1);
+
+    //Return the byte
+    return reg;
+}
+
+void LM75B::_write8(char reg, char data)
+{
+    //Create a temporary buffer
+    char buff[2];
+
+    //Load the register address and 8-bit data
+    buff[0] = reg;
+    buff[1] = data;
+
+    //Write the data
+    _i2c.write(_addr, buff, 2);
+}
+
+unsigned short LM75B::_read16(char reg)
+{
+    //Create a temporary buffer
+    char buff[2];
+
+    //Select the register
+    _i2c.write(_addr, &reg, 1);
+
+    //Read the 16-bit register
+    _i2c.read(_addr, buff, 2);
+
+    //Return the combined 16-bit value
+    return (buff[0] << 8) | buff[1];
+}
+
+void LM75B::_write16(char reg, unsigned short data)
+{
+    //Create a temporary buffer
+    char buff[3];
+
+    //Load the register address and 16-bit data
+    buff[0] = reg;
+    buff[1] = data >> 8;
+    buff[2] = data;
+
+    //Write the data
+    _i2c.write(_addr, buff, 3);
+}
+
+float LM75B::_readTempHelper(char reg)
+{
+    //Signed return value
+    short value;
+
+    //Read the 9-bit raw temperature value
+    value = _read16(reg) >> 7;
+
+    //Sign extend negative numbers
+    if (value & (1 << 8))
+        value |= 0xFF00;
+
+    //Return the temperature in °C
+    return value * 0.5;
+}
+
+void LM75B::_writeTempHelper(char reg, float temp)
+{
+    //Range limit temp
+    if (temp < -55.0)
+        temp = -55.0;
+    else if (temp > 125.0)
+        temp = 125.0;
+
+    //Extract and shift the signed integer
+    short value = temp * 2;
+    value <<= 7;
+
+    //Send the new value
+    _write16(reg, value);
+}