Diff: DS7505.cpp

Revision:

1:e1c7c1c636af

Child:

6:b6bafd0a7013

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/DS7505.cpp	Thu Apr 14 19:48:01 2016 +0000
@@ -0,0 +1,277 @@
+/*******************************************************************************
+* Copyright (C) 2016 Maxim Integrated Products, Inc., All Rights Reserved.
+*
+* 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 MAXIM INTEGRATED 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.
+*
+* Except as contained in this notice, the name of Maxim Integrated
+* Products, Inc. shall not be used except as stated in the Maxim Integrated
+* Products, Inc. Branding Policy.
+*
+* The mere transfer of this software does not imply any licenses
+* of trade secrets, proprietary technology, copyrights, patents,
+* trademarks, maskwork rights, or any other form of intellectual
+* property whatsoever. Maxim Integrated Products, Inc. retains all
+* ownership rights.
+*******************************************************************************
+*/
+
+#include "DS7505.hpp"
+#include "mbed.h"
+
+#define I2C_WRITE 0
+#define I2C_READ 1
+
+static const int I2C_WRITE_OK = 0;
+static const uint8_t DS7505_Config_SD_Bit = 0x01; // Enable shutdown mode
+
+DS7505::DS7505(I2C & I2C_interface, uint8_t I2C_address)
+  : m_current_config(Config_9b_Res, true), m_I2C_interface(I2C_interface), m_I2C_address(I2C_address)
+{
+  
+}
+
+uint8_t DS7505::get_measure_delay_ms(Config_Resolution resolution)
+{
+  uint8_t measure_delay_ms;
+  
+  switch (resolution)
+  {
+    case Config_9b_Res:
+      measure_delay_ms = 25;
+      break;
+    case Config_10b_Res:
+      measure_delay_ms = 50;
+      break;
+    case Config_11b_Res:
+      measure_delay_ms = 100;
+      break;
+    case Config_12b_Res:
+      measure_delay_ms = 200;
+      break;
+    default:
+      measure_delay_ms = 0;
+      break;
+  }
+  
+  return measure_delay_ms;
+}
+
+bool DS7505::read_temp_sensor_data(uint16_t & sensor_data) const
+{
+  bool result;
+  uint8_t upperByte, lowerByte;
+  int sub_res;
+  
+  sensor_data = 0;
+  m_I2C_interface.start();
+  sub_res = m_I2C_interface.write(m_I2C_address | I2C_READ);
+  if (sub_res == I2C_WRITE_OK)
+  {
+    upperByte = m_I2C_interface.read(I2C::ACK);
+    lowerByte = m_I2C_interface.read(I2C::NoACK);
+  }
+  m_I2C_interface.stop();
+  if (sub_res == I2C_WRITE_OK)
+  {
+    sensor_data = ((((uint16_t)upperByte) << 8) | lowerByte);
+    result = true;
+  }
+  else
+  {
+    // Handle hardware malfunction
+    result = false;
+  }
+  
+  return result;
+}
+
+bool DS7505::set_register_pointer(Register pointer_reg) const
+{
+  int res;
+  
+  m_I2C_interface.start();
+  res = m_I2C_interface.write(m_I2C_address | I2C_WRITE);
+  if (res == I2C_WRITE_OK)
+  {
+    res = m_I2C_interface.write(pointer_reg);
+  }
+  m_I2C_interface.stop();
+  
+  return (res == I2C_WRITE_OK);
+}
+
+bool DS7505::write_register(Register write_reg, uint8_t write_val) const
+{
+  bool res;
+  
+  m_I2C_interface.start();
+  res = m_I2C_interface.write(m_I2C_address | I2C_WRITE);
+  if (res == I2C_WRITE_OK)
+  {
+    res = m_I2C_interface.write(write_reg);
+    if (res == I2C_WRITE_OK)
+      res = m_I2C_interface.write(write_val);
+  }
+  m_I2C_interface.stop();
+  
+  return (res == I2C_WRITE_OK);
+}
+
+bool DS7505::write_current_config() const
+{
+  uint8_t DS7505_Config_Val = m_current_config.resolution;
+  if (m_current_config.enable_shutdown_mode)
+    DS7505_Config_Val |= DS7505_Config_SD_Bit;
+  return write_register(Configuration_Reg, DS7505_Config_Val);
+}
+
+DS7505::Result DS7505::set_resolution(uint8_t resolution)
+{   
+  switch (resolution)
+  {
+    case 1:
+      m_current_config.resolution = Config_9b_Res;
+      break;
+    case 2:
+      m_current_config.resolution = Config_10b_Res;
+      break;
+    case 3:
+      m_current_config.resolution = Config_11b_Res;
+      break;
+    case 4:
+      m_current_config.resolution = Config_12b_Res;
+      break;
+    default:
+      return Out_of_Range;
+  }
+  
+  // Write DS7505 configuration
+  if (!write_current_config())
+  {
+    // Handle hardware malfunction
+    return Hardware_Failure;
+  }
+  
+  // Set pointer to temperature register
+  if (!set_register_pointer(Temperature_Reg))
+  {
+    // Handle hardware malfunction
+    return Hardware_Failure;
+  }
+  
+  return Success;
+}
+
+DS7505::Result DS7505::read_temp_sensor(uint16_t & sensor_data) const
+{
+  bool res;
+  
+  if (m_current_config.enable_shutdown_mode)
+  {
+    // Disable shutdown mode
+    m_current_config.enable_shutdown_mode = false;
+    res = write_current_config();
+    if (!res)
+      return Hardware_Failure;
+  
+    // DS7505 measures temperature
+  
+    // Enable shutdown mode
+    m_current_config.enable_shutdown_mode = true;
+    res = write_current_config();
+    if (!res)
+      return Hardware_Failure;
+    
+    // Set pointer to temperature register
+    res = set_register_pointer(Temperature_Reg);
+    if (!res)
+      return Hardware_Failure;
+    
+    // Sleep for maximum time needed for sample
+    wait_ms(get_measure_delay_ms(m_current_config.resolution));
+  }
+  // else: shutdown mode disabled
+  //    DS7505 is constantly measuring temperature
+  
+  // Read temperature from sensor
+  if (!read_temp_sensor_data(sensor_data))
+  {
+    return Hardware_Failure;
+  }
+  
+  return Success;
+}
+
+DS7505::Result DS7505::read_current_temp(int16_t & temperature) const
+{
+  uint16_t sensor_data;
+  Result result;
+  
+  result = read_temp_sensor(sensor_data);
+  if (result == Success)
+  {
+    // Convert temperature to have an exponent of 10^-2
+    temperature = ((int8_t)(sensor_data >> 8)) * 100;
+    if (sensor_data & 0x0080)
+      temperature += 50; // 0.5
+    if (sensor_data & 0x0040)
+      temperature += 25; // 0.25
+    if (sensor_data & 0x0020)
+      temperature += 13; // 0.125
+    if (sensor_data & 0x0010)
+      temperature += 6; // 0.0625
+  }
+  return result;
+}
+
+DS7505::Result DS7505::read_current_temp(double & temperature) const
+{
+  uint16_t sensor_data;
+  Result result;
+  
+  result = read_temp_sensor(sensor_data);
+  if (result == Success)
+  {
+    // Convert sensor data to floating-point temperature
+    temperature = ((int8_t)(sensor_data >> 8));
+    if (sensor_data & 0x0080)
+      temperature += 0.5;
+    if (sensor_data & 0x0040)
+      temperature += 0.25;
+    if (sensor_data & 0x0020)
+      temperature += 0.125;
+    if (sensor_data & 0x0010)
+      temperature += 0.0625;
+  }
+  return result;
+}
+
+DS7505::Result DS7505::read_current_temp(int8_t & temperature) const
+{
+  uint16_t sensor_data;
+  Result result;
+  
+  result = read_temp_sensor(sensor_data);
+  if (result == Success)
+  {
+    // Convert sensor data to integer temperature
+    temperature = ((int8_t)(sensor_data >> 8));
+  }
+  return result;
+}
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