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.
DS7505.cpp
- Committer:
- IanBenzMaxim
- Date:
- 2018-01-19
- Revision:
- 35:3d414ba9ab6c
- Parent:
- 32:0a09505a656d
File content as of revision 35:3d414ba9ab6c:
/******************************************************************************* * 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 <I2C.h> #include <wait_api.h> #include "DS7505.hpp" static const int I2C_Write_Ok = 1; static const uint8_t DS7505_Config_SD_Bit = 0x01; // Enable shutdown mode DS7505::DS7505(mbed::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 | 1); if (sub_res == I2C_Write_Ok) { upperByte = m_I2C_interface.read(mbed::I2C::ACK); lowerByte = m_I2C_interface.read(mbed::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); 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); 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; }