Merge pull request #372 from dronecore/macos-serial

Serial connection support for macOS

cmake/compiler_flags.cmake

@@ -38,6 +38,10 @@ if(APPLE)
     add_definitions("-DAPPLE")
 endif()
 
+if(UNIX AND NOT APPLE)
+    add_definitions("-DLINUX")
+endif()
+
 # Add DEBUG define for Debug target because that is not done automatically.
 set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -DDEBUG")
 

core/dronecore.h

@@ -54,6 +54,8 @@ class DroneCore
      * Default URL : udp://:14540.
      * - Default Bind host IP is localhost(127.0.0.1)
      *
+     * Warning: serial connections are not supported on Windows (they are supported on Linux and macOS).
+     *
      * @param connection_url connection URL string.
      * @return The result of adding the connection.
      */
@@ -80,6 +82,9 @@ class DroneCore
     /**
      * @brief Adds a serial connection with a specific port (COM or UART dev node) and baudrate as specified.
      *
+     *
+     * Warning: this method is not supported on Windows (it is supported on Linux and macOS).
+     *
      * @param dev_path COM or UART dev node name/path (defaults to "/dev/ttyS0").
      * @param baudrate Baudrate of the serial port (defaults to 57600).
      * @return The result of adding the connection.

core/dronecore_impl.cpp

@@ -193,7 +193,7 @@ ConnectionResult DroneCoreImpl::add_tcp_connection(const std::string &remote_ip,
 ConnectionResult DroneCoreImpl::add_serial_connection(const std::string &dev_path,
                                                       int baudrate)
 {
-#if !defined(WINDOWS) && !defined(APPLE)
+#if !defined(WINDOWS)
     auto new_conn = std::make_shared<SerialConnection>(*this, dev_path, baudrate);
 
     ConnectionResult ret = new_conn->start();

core/serial_connection.cpp

@@ -1,17 +1,21 @@
-#if !defined(WINDOWS) && !defined(APPLE)
+#if !defined(WINDOWS)
 #include "serial_connection.h"
 #include "global_include.h"
 #include "log.h"
+#include <unistd.h>
+#include <fcntl.h>
+#include <cassert>
 
-#ifndef WINDOWS
+#ifdef LINUX
 #include <asm/termbits.h>
-#include <fcntl.h>
-#include <unistd.h>
 #include <sys/ioctl.h>
 #endif
 
-#include <cassert>
+#ifdef APPLE
+#include <termios.h>
+#endif
 
+// FIXME: this macro is not needed unless we actually support Windows.
 #ifndef WINDOWS
 #define GET_ERROR(_x) strerror(_x)
 #else
@@ -63,42 +67,86 @@ ConnectionResult SerialConnection::start()
 
 ConnectionResult SerialConnection::setup_port()
 {
-    struct termios2 tc;
-
-    bzero(&tc, sizeof(tc));
-
+#if defined(LINUX)
     _fd = open(_serial_node.c_str(), O_RDWR | O_NOCTTY);
     if (_fd == -1) {
+        LogErr() << "open failed: " << GET_ERROR(errno);
+        return ConnectionResult::CONNECTION_ERROR;
+    }
+#elif defined(APPLE)
+    // open() hangs on macOS unless you give it O_NONBLOCK
+    _fd = open(_serial_node.c_str(), O_RDWR | O_NOCTTY | O_NONBLOCK);
+    if (_fd == -1) {
+        LogErr() << "open failed: " << GET_ERROR(errno);
         return ConnectionResult::CONNECTION_ERROR;
     }
+    // We need to clear the O_NONBLOCK again because we can block while reading
+    // as we do it in a separate thread.
+    if (fcntl(_fd, F_SETFL, 0) == -1) {
+        LogErr() << "fcntl failed: " << GET_ERROR(errno);
+        return ConnectionResult::CONNECTION_ERROR;
+    }
+#endif
+
+#if defined(LINUX)
+    struct termios2 tc;
+    bzero(&tc, sizeof(tc));
+
     if (ioctl(_fd, TCGETS2, &tc) == -1) {
         LogErr() << "Could not get termios2 " << GET_ERROR(errno);
         close(_fd);
         return ConnectionResult::CONNECTION_ERROR;
     }
+#elif defined(APPLE)
+    struct termios tc;
+    bzero(&tc, sizeof(tc));
+
+    if (tcgetattr(_fd, &tc) != 0) {
+        LogErr() << "tcgetattr failed: " << GET_ERROR(errno);
+        close(_fd);
+        return ConnectionResult::CONNECTION_ERROR;
+    }
+#endif
 
     tc.c_iflag &= ~(IGNBRK | BRKINT | ICRNL | INLCR | PARMRK | INPCK | ISTRIP | IXON);
     tc.c_oflag &= ~(OCRNL | ONLCR | ONLRET | ONOCR | OFILL | OPOST);
     tc.c_lflag &= ~(ECHO | ECHONL | ICANON | IEXTEN | ISIG | TOSTOP);
-    tc.c_cflag &= ~(CSIZE | PARENB | CBAUD | CRTSCTS);
-    tc.c_cflag |= CS8 | BOTHER;
+    tc.c_cflag &= ~(CSIZE | PARENB | CRTSCTS);
+    tc.c_cflag |= CS8;
 
     tc.c_cc[VMIN] = 1; // We want at least 1 byte to be available.
     tc.c_cc[VTIME] = 0; // We don't timeout but wait indefinitely.
-    tc.c_ispeed = _baudrate;
-    tc.c_ospeed = _baudrate;
+
+#if defined(LINUX)
+    // CBAUD and BOTHER don't seem to be available for macOS with termios.
+    tc.c_cflag &= ~(CBAUD);
+    tc.c_cflag |= BOTHER;
 
     if (ioctl(_fd, TCSETS2, &tc) == -1) {
         LogErr() << "Could not set terminal attributes " << GET_ERROR(errno);
         close(_fd);
         return ConnectionResult::CONNECTION_ERROR;
     }
 
+
     if (ioctl(_fd, TCFLSH, TCIOFLUSH) == -1) {
         LogErr() << "Could not flush terminal " << GET_ERROR(errno);
         close(_fd);
         return ConnectionResult::CONNECTION_ERROR;
     }
+#elif defined(APPLE)
+    tc.c_cflag |= CLOCAL; // Without this a write() blocks indefinitely.
+
+    cfsetispeed(&tc, _baudrate);
+    cfsetospeed(&tc, _baudrate);
+
+    if (tcsetattr(_fd, TCSANOW, &tc) != 0) {
+        LogErr() << "tcsetattr failed: " << GET_ERROR(errno);
+        close(_fd);
+        return ConnectionResult::CONNECTION_ERROR;
+    }
+#endif
+
     return ConnectionResult::SUCCESS;
 }
 

core/serial_connection.h

@@ -1,5 +1,5 @@
 #pragma once
-#if !defined(WINDOWS) && !defined(APPLE)
+#if !defined(WINDOWS)
 
 #include <mutex>
 #include <atomic>

example/fly_mission/CMakeLists.txt

@@ -19,4 +19,5 @@ target_link_libraries(fly_mission
     dronecore_action
     dronecore_mission
     dronecore_telemetry
+    json11
 )

example/fly_mission/fly_mission.cpp

@@ -48,7 +48,9 @@ static std::shared_ptr<MissionItem> make_mission_item(double latitude_deg,
                                                       float gimbal_yaw_deg,
                                                       MissionItem::CameraAction camera_action);
 
-int main(int /*argc*/, char ** /*argv*/)
+void usage(std::string arg);
+
+int main(int argc, char **argv)
 {
     DroneCore dc;
 
@@ -62,8 +64,23 @@ int main(int /*argc*/, char ** /*argv*/)
             prom->set_value();
         });
 
-        ConnectionResult connection_result = dc.add_udp_connection();
-        handle_connection_err_exit(connection_result, "Connection failed: ");
+        std::string connection_url;
+        ConnectionResult connection_result;
+
+        if (argc == 1) {
+            usage(argv[0]);
+            connection_result = dc.add_any_connection();
+        } else {
+            connection_url = argv[1];
+            connection_result = dc.add_any_connection(connection_url);
+        }
+
+        if (connection_result != ConnectionResult::SUCCESS) {
+            std::cout << ERROR_CONSOLE_TEXT << "Connection failed: "
+                      << connection_result_str(connection_result)
+                      << NORMAL_CONSOLE_TEXT << std::endl;
+            return 1;
+        }
 
         future_result.get();
     }
@@ -301,3 +318,13 @@ inline void handle_connection_err_exit(ConnectionResult result,
         exit(EXIT_FAILURE);
     }
 }
+
+void usage(std::string arg)
+{
+    std::cout << NORMAL_CONSOLE_TEXT << "Usage : " << arg << " [connection_url]" << std::endl
+              << "Connection URL format should be :" << std::endl
+              << " For TCP : tcp://[server_host][:server_port]" << std::endl
+              << " For UDP : udp://[bind_host][:bind_port]" << std::endl
+              << " For Serial : serial:///path/to/serial/dev[:baudrate]" << std::endl;
+    std::cout << "Default connection URL is udp://:14540" << std::endl;
+}