Merge pull request #60 from sarfata/seasmart-converter

Seasmart converter

.gitignore

@@ -41,3 +41,7 @@ $RECYCLE.BIN/
 Network Trash Folder
 Temporary Items
 .apdisk
+
+# CMake
+build
+tags

.travis.yml

@@ -0,0 +1,45 @@
+sudo: false
+language: cpp
+matrix:
+    - compiler: gcc
+      addons:
+        apt:
+          sources: ['ubuntu-toolchain-r-test']
+          packages: ['g++-4.4']
+    - compiler: gcc
+      addons:
+        apt:
+          sources: ['ubuntu-toolchain-r-test']
+          packages: ['g++-4.5']
+    - compiler: gcc
+      addons:
+        apt:
+          sources: ['ubuntu-toolchain-r-test']
+          packages: ['g++-4.6']
+    - compiler: gcc
+      addons:
+        apt:
+          sources: ['ubuntu-toolchain-r-test']
+          packages: ['g++-4.7']
+    - compiler: gcc
+      addons:
+        apt:
+          sources: ['ubuntu-toolchain-r-test']
+          packages: ['g++-4.8']
+    - compiler: gcc
+      addons:
+        apt:
+          sources: ['ubuntu-toolchain-r-test']
+          packages: ['g++-4.9']
+    - compiler: gcc
+      addons:
+        apt:
+          sources: ['ubuntu-toolchain-r-test']
+          packages: ['g++-5']
+    - compiler: gcc
+      addons:
+        apt:
+          sources: ['ubuntu-toolchain-r-test']
+          packages: ['g++-6']
+    - compiler: clang
+script: scripts/cmake.sh

CMakeLists.txt

@@ -0,0 +1,37 @@
+#  The MIT License
+#
+#  Copyright (c) 2017 Thomas Sarlandie [email protected]
+#
+#  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.
+
+cmake_minimum_required(VERSION 3.0)
+project(NMEA2000)
+
+add_compile_options(
+  -Wall
+  -Werror
+  -std=c++11
+  -g
+)
+
+enable_testing()
+
+add_subdirectory(src)
+add_subdirectory(third-party/catch)
+add_subdirectory(test)

README.adoc

@@ -493,6 +493,14 @@ For use with Atmel AVR processors internal CAN controller
 
 - https://www.nmea.org/Assets/20140102%20nmea-2000-126993%20heartbeat%20pgn%20corrigendum.pdf[Heartbeat PGN 126993]
 
+== Running Tests ==
+
+To run the unit tests, you must have `cmake` installed:
+
+    cmake .
+    cmake --build .
+    ctest .
+
 == License ==
 
 Copyright (c) 2015-2017 Timo Lappalainen, Kave Oy, www.kave.fi

scripts/cmake.sh

@@ -0,0 +1,6 @@
+#!/bin/sh -ex
+
+cmake .
+cmake --build .
+ctest --output-on-failure .
+

src/CMakeLists.txt

@@ -0,0 +1,35 @@
+
+#  The MIT License
+#
+#  Copyright (c) 2017 Thomas Sarlandie [email protected]
+#
+#  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.
+
+
+add_library(nmea2000
+  N2kMsg.cpp
+  N2kStream.cpp
+  N2kMessages.cpp
+  Seasmart.cpp
+)
+
+target_include_directories(nmea2000
+  PUBLIC
+  ${CMAKE_CURRENT_SOURCE_DIR}
+)

src/Seasmart.cpp

@@ -0,0 +1,187 @@
+/*
+  The MIT License
+
+  Copyright (c) 2017 Thomas Sarlandie [email protected]
+
+  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 <string.h>
+#include <ctype.h>
+#include <stdlib.h>
+#include "Seasmart.h"
+
+/* Some private helper functions to generate hex-serialized NMEA messages */
+static const char *hex = "0123456789ABCDEF";
+
+static int appendByte(char *s, uint8_t byte) {
+  s[0] = hex[byte >> 4];
+  s[1] = hex[byte & 0xf];
+  return 2;
+}
+
+static int append2Bytes(char *s, uint16_t i) {
+  appendByte(s, i >> 8);
+  appendByte(s + 2, i & 0xff);
+  return 4;
+}
+
+static int appendWord(char *s, uint32_t i) {
+  append2Bytes(s, i >> 16);
+  append2Bytes(s + 4, i & 0xffff);
+  return 8;
+}
+
+static uint8_t nmea_compute_checksum(const char *sentence) {
+  if (sentence == 0) {
+    return 0;
+  }
+
+  // Skip the $ at the beginning
+  int i = 1;
+
+  int checksum = 0;
+  while (sentence[i] != '*') {
+    checksum ^= sentence[i];
+    i++;
+  }
+  return checksum;
+}
+
+size_t N2kToSeasmart(const tN2kMsg &msg, uint32_t timestamp, char *buffer, size_t size) {
+  size_t pcdin_sentence_length = 6+1+6+1+8+1+2+1+msg.DataLen*2+1+2 + 1;
+
+  if (size < pcdin_sentence_length) {
+    return 0;
+  }
+
+  char *s = buffer;
+
+  strcpy(s, "$PCDIN,");
+  s += 7;
+  s += appendByte(s, msg.PGN >> 16);
+  s += append2Bytes(s, msg.PGN & 0xffff);
+  *s++ = ',';
+  s += appendWord(s, timestamp);
+  *s++ = ',';
+  s += appendByte(s, msg.Source);
+  *s++ = ',';
+
+  for (int i = 0; i < msg.DataLen; i++) {
+    s += appendByte(s, msg.Data[i]);
+  }
+
+  *s++ = '*';
+  s += appendByte(s, nmea_compute_checksum(buffer));
+  *s = 0;
+
+  return (size_t)(s - buffer);
+}
+
+/*
+ * Attemts to read n bytes in hexadecimal from input string to value.
+ *
+ * Returns true if successful, false otherwise.
+ */
+static bool readNHexByte(const char *s, unsigned int n, uint32_t &value) {
+  if (strlen(s) < 2*n) {
+    return -1;
+  }
+  for (unsigned int i = 0; i < 2*n; i++) {
+    if (!isxdigit(s[i])) {
+      return -1;
+    }
+  }
+
+  char sNumber[2*n + 1];
+  strncpy(sNumber, s, sizeof(sNumber));
+  sNumber[sizeof(sNumber) - 1] = 0;
+
+  value = strtol(sNumber, 0, 16);
+  return true;
+}
+
+bool SeasmartToN2k(const char *buffer, uint32_t &timestamp, tN2kMsg &msg) {
+  msg.Clear();
+
+  const char *s = buffer;
+  if (strncmp("$PCDIN,", s, 6) != 0) {
+    return false;
+  }
+  s += 7;
+
+  uint32_t pgnHigh;
+  uint32_t pgnLow;
+  if (!readNHexByte(s, 1, pgnHigh)) {
+    return false;
+  }
+  s += 2;
+  if (!readNHexByte(s, 2, pgnLow)) {
+    return false;
+  }
+  s += 5;
+  msg.PGN = (pgnHigh << 16) + pgnLow;
+
+  if (!readNHexByte(s, 4, timestamp)) {
+    return false;
+  }
+  s += 9;
+
+  uint32_t source;
+  if (!readNHexByte(s, 1, source)) {
+    return false;
+  }
+  msg.Source = source;
+  s += 3;
+
+  int dataLen = 0;
+  while (s[dataLen] != 0 && s[dataLen] != '*') {
+    dataLen++;
+  }
+  if (dataLen % 2 != 0) {
+    return false;
+  }
+  dataLen /= 2;
+
+  msg.DataLen = dataLen;
+  if (msg.DataLen > msg.MaxDataLen) {
+    return false;
+  }
+  for (int i = 0; i < dataLen; i++) {
+    uint32_t byte;
+    if (!readNHexByte(s, 1, byte)) {
+      return false;
+    }
+    msg.Data[i] = byte;
+    s += 2;
+  }
+
+  // Skip the terminating '*' which marks beginning of checksum
+  s += 1;
+  uint32_t checksum;
+  if (!readNHexByte(s, 1, checksum)) {
+    return false;
+  }
+
+  if (checksum != nmea_compute_checksum(buffer)) {
+    return false;
+  }
+
+  return true;
+}

src/Seasmart.h

@@ -0,0 +1,58 @@
+/*
+  The MIT License
+
+  Copyright (c) 2017 Thomas Sarlandie [email protected]
+
+  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.
+*/
+
+#ifndef _Seasmart_h_
+#define _Seasmart_h_
+
+#include <N2kMsg.h>
+
+/**
+ * Converts a tN2kMsg into a $PCDIN NMEA sentence, following the Seasmart
+ * specification.  The buffer must be at least (30 + 2*msg.DataLen) bytes long.
+ *
+ * Reference: http://www.seasmart.net/pdf/SeaSmart_HTTP_Protocol_RevG_043012.pdf
+ *
+ * If the buffer is not long enough, this function returns 0 and does not do
+ * anything.
+ *
+ * If the buffer is long enough, this function returns the number of bytes
+ * written including the terminating \0 (but this function does not add the
+ * NMEA separator \r\n).
+ */
+size_t N2kToSeasmart(const tN2kMsg &msg, uint32_t timestamp, char *buffer, size_t size);
+
+/**
+ * Converts a null terminated $PCDIN NMEA sentence into a tN2kMsg and updates
+ * timestamp with the timestamp of the sentence.
+ *
+ * Reference: http://www.seasmart.net/pdf/SeaSmart_HTTP_Protocol_RevG_043012.pdf
+ *
+ * The NMEA \r\n terminator is not required.
+ *
+ * Returns true if it succeeded.
+ * Returns false if an error occured.
+ */
+bool SeasmartToN2k(const char *buffer, uint32_t &timestamp, tN2kMsg &msg);
+
+#endif