Maxim Integrated / Mbed OS MAXREFDES155#

DeepCover Embedded Security in IoT: Public-key Secured Data Paths

Dependencies:   MaximInterface

The MAXREFDES155# is an internet-of-things (IoT) embedded-security reference design, built to authenticate and control a sensing node using elliptic-curve-based public-key cryptography with control and notification from a web server.

The hardware includes an ARM® mbed™ shield and attached sensor endpoint. The shield contains a DS2476 DeepCover® ECDSA/SHA-2 coprocessor, Wifi communication, LCD push-button controls, and status LEDs. The sensor endpoint is attached to the shield using a 300mm cable and contains a DS28C36 DeepCover ECDSA/SHA-2 authenticator, IR-thermal sensor, and aiming laser for the IR sensor. The MAXREFDES155# is equipped with a standard Arduino® form-factor shield connector for immediate testing using an mbed board such as the MAX32600MBED#. The combination of these two devices represent an IoT device. Communication to the web server is accomplished with the shield Wifi circuitry. Communication from the shield to the attached sensor module is accomplished over I2C . The sensor module represents an IoT endpoint that generates small data with a requirement for message authenticity/integrity and secure on/off operational control.

The design is hierarchical with each mbed platform and shield communicating data from the sensor node to a web server that maintains a centralized log and dispatches notifications as necessary. The simplicity of this design enables rapid integration into any star-topology IoT network to provide security with the low overhead and cost provided by the ECDSA-P256 asymmetric-key and SHA-256 symmetric-key algorithms.

More information about the MAXREFDES155# is available on the Maxim Integrated website.

Display.cpp@10:71359af61af8, 2017-04-10 (annotated)

Committer:
IanBenzMaxim
Date:
Mon Apr 10 11:55:33 2017 -0500
Revision:
10:71359af61af8
Parent:
0:33d4e66780c0
Child:
11:989eabe2a376
Reduced copying and dynamic allocations during rendering. Added support for partial redrawing of a scene.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
IanBenzMaxim 0:33d4e66780c0 1 /*******************************************************************************
IanBenzMaxim 0:33d4e66780c0 2 * Copyright (C) 2017 Maxim Integrated Products, Inc., All Rights Reserved.
IanBenzMaxim 0:33d4e66780c0 3 *
IanBenzMaxim 0:33d4e66780c0 4 * Permission is hereby granted, free of charge, to any person obtaining a
IanBenzMaxim 0:33d4e66780c0 5 * copy of this software and associated documentation files (the "Software"),
IanBenzMaxim 0:33d4e66780c0 6 * to deal in the Software without restriction, including without limitation
IanBenzMaxim 0:33d4e66780c0 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
IanBenzMaxim 0:33d4e66780c0 8 * and/or sell copies of the Software, and to permit persons to whom the
IanBenzMaxim 0:33d4e66780c0 9 * Software is furnished to do so, subject to the following conditions:
IanBenzMaxim 0:33d4e66780c0 10 *
IanBenzMaxim 0:33d4e66780c0 11 * The above copyright notice and this permission notice shall be included
IanBenzMaxim 0:33d4e66780c0 12 * in all copies or substantial portions of the Software.
IanBenzMaxim 0:33d4e66780c0 13 *
IanBenzMaxim 0:33d4e66780c0 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
IanBenzMaxim 0:33d4e66780c0 15 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
IanBenzMaxim 0:33d4e66780c0 16 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IanBenzMaxim 0:33d4e66780c0 17 * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
IanBenzMaxim 0:33d4e66780c0 18 * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
IanBenzMaxim 0:33d4e66780c0 19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
IanBenzMaxim 0:33d4e66780c0 20 * OTHER DEALINGS IN THE SOFTWARE.
IanBenzMaxim 0:33d4e66780c0 21 *
IanBenzMaxim 0:33d4e66780c0 22 * Except as contained in this notice, the name of Maxim Integrated
IanBenzMaxim 0:33d4e66780c0 23 * Products, Inc. shall not be used except as stated in the Maxim Integrated
IanBenzMaxim 0:33d4e66780c0 24 * Products, Inc. Branding Policy.
IanBenzMaxim 0:33d4e66780c0 25 *
IanBenzMaxim 0:33d4e66780c0 26 * The mere transfer of this software does not imply any licenses
IanBenzMaxim 0:33d4e66780c0 27 * of trade secrets, proprietary technology, copyrights, patents,
IanBenzMaxim 0:33d4e66780c0 28 * trademarks, maskwork rights, or any other form of intellectual
IanBenzMaxim 0:33d4e66780c0 29 * property whatsoever. Maxim Integrated Products, Inc. retains all
IanBenzMaxim 0:33d4e66780c0 30 * ownership rights.
IanBenzMaxim 0:33d4e66780c0 31 *******************************************************************************/
IanBenzMaxim 0:33d4e66780c0 32
IanBenzMaxim 0:33d4e66780c0 33 #include "Display.hpp"
IanBenzMaxim 0:33d4e66780c0 34
IanBenzMaxim 10:71359af61af8 35 /// @{
IanBenzMaxim 10:71359af61af8 36 /// Width and height of the display in pixels.
IanBenzMaxim 10:71359af61af8 37 static const int width = 128;
IanBenzMaxim 10:71359af61af8 38 static const int height = 64;
IanBenzMaxim 10:71359af61af8 39 /// @}
IanBenzMaxim 10:71359af61af8 40
IanBenzMaxim 0:33d4e66780c0 41 Display::Display(PinName mosi, PinName miso, PinName sclk, PinName ssel, PinName a0) :
IanBenzMaxim 10:71359af61af8 42 m_canvas(width, height), spi(mosi, miso, sclk), cs(ssel, 1), a0(a0, 0)
IanBenzMaxim 0:33d4e66780c0 43 {
IanBenzMaxim 0:33d4e66780c0 44 spi.format(8, 3); // CPOL = 1, CPHA = 1
IanBenzMaxim 0:33d4e66780c0 45 }
IanBenzMaxim 0:33d4e66780c0 46
IanBenzMaxim 0:33d4e66780c0 47 void Display::initialize()
IanBenzMaxim 0:33d4e66780c0 48 {
IanBenzMaxim 0:33d4e66780c0 49 sendCommand(0xA0);
IanBenzMaxim 0:33d4e66780c0 50 sendCommand(0xAE);
IanBenzMaxim 0:33d4e66780c0 51 sendCommand(0xC0);
IanBenzMaxim 0:33d4e66780c0 52 sendCommand(0xA2);
IanBenzMaxim 0:33d4e66780c0 53 sendCommand(0x2F);
IanBenzMaxim 0:33d4e66780c0 54 sendCommand(0x26);
IanBenzMaxim 0:33d4e66780c0 55 sendCommand(0x81);
IanBenzMaxim 0:33d4e66780c0 56 sendCommand(0x11);
IanBenzMaxim 0:33d4e66780c0 57 sendCommand(0xAF);
IanBenzMaxim 0:33d4e66780c0 58 }
IanBenzMaxim 0:33d4e66780c0 59
IanBenzMaxim 10:71359af61af8 60 void Display::update()
IanBenzMaxim 0:33d4e66780c0 61 {
IanBenzMaxim 0:33d4e66780c0 62 sendCommand(0xAE);
IanBenzMaxim 0:33d4e66780c0 63 sendCommand(0x40);
IanBenzMaxim 0:33d4e66780c0 64 const int rowsPerPage = 8;
IanBenzMaxim 0:33d4e66780c0 65 int row = -rowsPerPage;
IanBenzMaxim 10:71359af61af8 66 int column = m_canvas.width();
IanBenzMaxim 10:71359af61af8 67 for (Bitmap::SegmentBuffer::const_iterator it = m_canvas.data().begin(); it != m_canvas.data().end(); it++)
IanBenzMaxim 0:33d4e66780c0 68 {
IanBenzMaxim 10:71359af61af8 69 if (column == m_canvas.width())
IanBenzMaxim 0:33d4e66780c0 70 {
IanBenzMaxim 0:33d4e66780c0 71 row += rowsPerPage;
IanBenzMaxim 0:33d4e66780c0 72 if (row >= height) // Height of the canvas is greater than height of the display.
IanBenzMaxim 0:33d4e66780c0 73 break;
IanBenzMaxim 0:33d4e66780c0 74 column = 0;
IanBenzMaxim 0:33d4e66780c0 75 sendCommand(0xB0 + static_cast<uint8_t>(row / rowsPerPage));
IanBenzMaxim 0:33d4e66780c0 76 sendCommand(0x10);
IanBenzMaxim 0:33d4e66780c0 77 sendCommand(0x00);
IanBenzMaxim 0:33d4e66780c0 78 }
IanBenzMaxim 0:33d4e66780c0 79 if (column < width)
IanBenzMaxim 0:33d4e66780c0 80 {
IanBenzMaxim 0:33d4e66780c0 81 sendData(*it);
IanBenzMaxim 0:33d4e66780c0 82 }
IanBenzMaxim 0:33d4e66780c0 83 column++;
IanBenzMaxim 0:33d4e66780c0 84 }
IanBenzMaxim 0:33d4e66780c0 85 sendCommand(0xAF);
IanBenzMaxim 0:33d4e66780c0 86 }
IanBenzMaxim 0:33d4e66780c0 87
IanBenzMaxim 0:33d4e66780c0 88 void Display::sendCommand(uint8_t command)
IanBenzMaxim 0:33d4e66780c0 89 {
IanBenzMaxim 0:33d4e66780c0 90 cs = 0;
IanBenzMaxim 0:33d4e66780c0 91 a0 = 0;
IanBenzMaxim 0:33d4e66780c0 92 spi.write(command);
IanBenzMaxim 0:33d4e66780c0 93 cs = 1;
IanBenzMaxim 0:33d4e66780c0 94 }
IanBenzMaxim 0:33d4e66780c0 95
IanBenzMaxim 0:33d4e66780c0 96 void Display::sendData(uint8_t data)
IanBenzMaxim 0:33d4e66780c0 97 {
IanBenzMaxim 0:33d4e66780c0 98 cs = 0;
IanBenzMaxim 0:33d4e66780c0 99 a0 = 1;
IanBenzMaxim 0:33d4e66780c0 100 spi.write(data);
IanBenzMaxim 0:33d4e66780c0 101 cs = 1;
IanBenzMaxim 0:33d4e66780c0 102 }