squash ds18b20 devel branch

tracker/code/CMakeLists.txt

@@ -4,6 +4,8 @@ cmake_minimum_required( VERSION 3.1 )
 project (pizero_tracker)
 
 set ( CMAKE_CXX_STANDARD 11 )
+set ( CMAKE_CXX_STANDARD_REQUIRED ON )
+
 set ( CMAKE_BUILD_TYPE "Release" )
 
 option( build_tests "build tests" 0 )
@@ -11,4 +13,5 @@ option( build_tests "build tests" 0 )
 if( ${build_tests} )
 	add_subdirectory( ublox )
 	add_subdirectory( mtx2 )
+	add_subdirectory( ds18b20 )
 endif()

tracker/code/ds18b20/CMakeLists.txt

@@ -0,0 +1,12 @@
+
+# req. by stdc++fs
+CMAKE_POLICY(SET CMP0079 NEW)
+
+set (ds18b20_test_src
+	ds18b20.h ds18b20.cpp
+	ds18b20_test.cpp
+)
+
+include_directories( ${CMAKE_SOURCE_DIR} )
+
+add_executable( ds18b20_test ${ds18b20_test_src} )

tracker/code/ds18b20/ds18b20.cpp

@@ -0,0 +1,95 @@
+#include "ds18b20.h"
+
+#include <dirent.h>
+
+#include <vector>
+#include <string>
+// #include <iostream>
+#include <fstream>
+#include <regex>
+
+
+namespace
+{
+
+std::vector<std::string>  get_dir_content(const std::string dir)
+{
+    std::vector<std::string> ret;
+
+    DIR* dp;
+    if( (dp  = opendir(dir.c_str())) == NULL)
+        return ret;
+
+    struct dirent *dirp;
+    while ((dirp = readdir(dp)) != NULL)
+        ret.push_back(std::string(dirp->d_name));
+    closedir(dp);
+
+    return ret;
+}
+} // ns
+
+std::string find_ds18b20_device(const std::string& base_dir) // "/sys/bus/w1/devices/"
+{
+    using namespace std;
+    auto cont = get_dir_content( base_dir );
+    for(const auto& f : cont)
+        if( f.substr(0, 3) == "28-" )
+            return base_dir + "/" + f + "/w1_slave";
+    return "";
+}
+
+
+float read_temp_from_ds18b20(const std::string& device)
+{
+    using namespace std;
+    ifstream ds18b20_file( device );
+    if ( !ds18b20_file.is_open() )
+        return -99;
+
+    /*
+    8a 01 4b 46 7f ff 06 10 2c : crc=2c YES
+    8a 01 4b 46 7f ff 06 10 2c t=24625
+    */
+
+
+    vector<string> file_lines;
+    string line;
+    while ( getline (ds18b20_file,line) )
+        file_lines.push_back(line);
+
+    // crc
+    //
+    const std::regex rex_crc( R"_(^\s*?([\w\w\s]+): crc=(\d\w) (YES)\s*$)_" );
+    smatch match_crc;
+    bool crc_ok = false;
+    for( const auto& l : file_lines )
+    {
+        regex_match(l, match_crc, rex_crc);
+        if( match_crc.size() == 4 && match_crc[3] == "YES" )
+        {
+            crc_ok = true;
+            break;
+        }
+    }
+
+    if(!crc_ok)
+        return -98;
+
+    // temp
+    //
+    const std::regex rex_temp( R"_(^\s*?([\w\w\s]+) t=(\d+)\s*$)_" );
+    smatch match_temp;
+    for( const auto& l : file_lines )
+    {
+        regex_match(l, match_temp, rex_temp);
+        if( match_temp.size() != 3)
+            continue;
+        float temp = stof( match_temp[2] ) / 1000.0f;
+        return temp;
+    }
+
+    ds18b20_file.close();
+
+    return -99;
+}

tracker/code/ds18b20/ds18b20.h

@@ -0,0 +1,5 @@
+#include <string>
+
+std::string find_ds18b20_device(const std::string& base_dir = "/sys/bus/w1/devices/" );
+
+float read_temp_from_ds18b20(const std::string& device);

tracker/code/ds18b20/ds18b20_test.cpp

@@ -0,0 +1,26 @@
+#include "ds18b20.h"
+
+#include <unistd.h>
+#include <string>
+#include <iostream>
+
+
+int main()
+{
+
+    using namespace std;
+
+    string ds18b20_device = find_ds18b20_device();
+    cout<<"ds18b20_device: '"<<ds18b20_device<<"'"<<endl;
+    if(ds18b20_device == "")
+        return 1;
+
+    int retries = 5;
+    while(retries--)
+    {
+        cout<<"temp = "<<read_temp_from_ds18b20(ds18b20_device)<<endl;
+        sleep(1);
+    }
+
+    return 0;
+}