MAXREFDES143#: DeepCover Embedded Security in IoT Authenticated Sensing & Notification

Dependencies:   MaximInterface mbed

The MAXREFDES143# is an Internet of Things (IoT) embedded security reference design, built to protect an industrial sensing node by means of authentication and notification to a web server. The hardware includes a peripheral module representing a protected sensor node monitoring operating temperature and remaining life of a filter (simulated through ambient light sensing) and an mbed shield representing a controller node responsible for monitoring one or more sensor nodes. The design is hierarchical with each controller node communicating data from connected sensor nodes to a web server that maintains a centralized log and dispatches notifications as necessary. The mbed shield contains a Wi-Fi module, a DS2465 coprocessor with 1-Wire® master function, an LCD, LEDs, and pushbuttons. The protected sensor node contains a DS28E15 authenticator, a DS7505 temperature sensor, and a MAX44009 light sensor. The mbed shield communicates to a web server by the onboard Wi-Fi module and to the protected sensor node with I2C and 1-Wire. The MAXREFDES143# is equipped with a standard shield connector for immediate testing using an mbed board such as the MAX32600MBED#. The simplicity of this design enables rapid integration into any star-topology IoT network requiring the heightened security with low overhead provided by the SHA-256 symmetric-key algorithm.

More information about the MAXREFDES143# is available on the Maxim Integrated website.

Revision:
1:e1c7c1c636af
Child:
6:b6bafd0a7013
diff -r 19b8608fc4ee -r e1c7c1c636af DS7505.hpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/DS7505.hpp	Thu Apr 14 19:48:01 2016 +0000
@@ -0,0 +1,141 @@
+/*******************************************************************************
+* 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.
+*******************************************************************************
+*/
+
+#ifndef _DS7505_HPP
+#define _DS7505_HPP
+
+#include <cstdint>
+
+namespace mbed
+{
+  class I2C;
+}
+
+/// Interface to the DS7505 temperature sensor.
+class DS7505
+{
+public:
+  enum Result
+  {
+    Success,
+    Hardware_Failure,
+    Out_of_Range
+  };
+  
+  /// @param I2C_interface A configured I2C interface to use for communication.
+  /// @param I2C_address Device bus address in mbed format.
+  DS7505(mbed::I2C & I2C_interface, std::uint8_t I2C_address);
+  
+  /// Set the resolution for temperature conversions.
+  /// @param resolution Number of decimal bit from 1 to 4.
+  Result set_resolution(std::uint8_t resolution);
+  
+  /// Reads the current temperature with an exponent of 10^-2.
+  /// @note Compatible with Bluetooth characteristic: org.bluetooth.characteristic.temperature.
+  Result read_current_temp(std::int16_t & temperature) const;
+  
+  /// Reads the current temperature as a floating point value.
+  Result read_current_temp(double & temperature) const;
+  
+  /// Reads the current temperature as an integer value.
+  Result read_current_temp(std::int8_t & temperature) const;
+  
+private:
+  /// Bit resolution of temperature conversions.
+  enum Config_Resolution
+  {
+    Config_9b_Res = 0x00,
+    Config_10b_Res = 0x20,
+    Config_11b_Res = 0x40,
+    Config_12b_Res = 0x60
+  };
+  
+  /// DS7505 Register addresses.
+  enum Register
+  {
+    Temperature_Reg = 0x00,
+    Configuration_Reg = 0x01,
+    Thyst_Reg = 0x02,
+    Tos_Reg = 0x03
+  };
+  
+  /// Represents a DS7505 configuration.
+  struct Config
+  {
+    Config_Resolution resolution;
+    bool enable_shutdown_mode;
+    
+    Config(Config_Resolution resolution, bool enable_shutdown_mode)
+      : resolution(resolution), enable_shutdown_mode(enable_shutdown_mode) { }
+  };
+  
+  /// @note Mark as mutable to allow manipulation by read_temp_sensor().
+  mutable Config m_current_config;
+  
+  mbed::I2C & m_I2C_interface;
+  std::uint8_t m_I2C_address;
+  
+  /// Returns the maximum time needed in ms for a sample at the specified resolution.
+  static std::uint8_t get_measure_delay_ms(Config_Resolution resolution);
+  
+  /// Reads the current temperature via I2C.
+  /// Assumes that the I2C register pointer is already set to the temperature register.
+  /// @param sensor_data Output for raw data from DS7505 with upper and lower bytes combined.
+  /// @returns True on success.
+  bool read_temp_sensor_data(std::uint16_t & sensor_data) const;
+  
+  /// Reads the current temperature with support for shutdown mode.
+  /// @param sensor_data Output for raw data from DS7505 with upper and lower bytes combined.
+  /// @returns Success or Hardware_Failure.
+  Result read_temp_sensor(std::uint16_t & sensor_data) const;
+  
+  /// Sets the I2C register pointer for the next operation.
+  /// @param pointer_reg Desired register to set.
+  /// @returns True on success.
+  /// @note Allow marking const since not public.
+  bool set_register_pointer(Register pointer_reg) const;
+  
+  /// Writes to a device register via I2C.
+  /// @param write_reg Register to write to.
+  /// @param write_val Value to write to the register.
+  /// @returns True on success.
+  /// @note Allow marking const since not public
+  bool write_register(Register write_reg, std::uint8_t write_val) const;
+  
+  /// Writes the current configuration via I2C.
+  /// @returns True on success.
+  /// @note Allow marking const since not public
+  bool write_current_config() const;
+};
+
+#endif