Basic custom baud rate functionality working.

Geoffrey Hunter
1 parent 9ed00102
Showing 6 changed files with 332 additions and 74 deletions
.vscode/c_cpp_properties.json
README.md
include/CppLinuxSerial/SerialPort.hpp
src/SerialPort.cpp
test/arduino/Basic/Basic.ino
test/arduino/main.cpp
@@ -60,7 +60,8 @@
             },
             "compilerPath": "/usr/bin/gcc",
             "cStandard": "c11",
-            "cppStandard": "c++17"
+            "cppStandard": "c++17",
+            "configurationProvider": "ms-vscode.cmake-tools"
         },
         {
             "name": "Win32",
@@ -66,18 +66,19 @@ using namespace mn::CppLinuxSerial;
 int main() {
 	// Create serial port object and open serial port
-	SerialPort serialPort0("/dev/ttyUSB0", BaudRate::B_57600);
-	serialPort0.Open();
+	SerialPort serialPort("/dev/ttyUSB0", BaudRate::B_57600);
+	serialPort.SetTimeout(-1); // Block when reading until any data is received
+	serialPort.Open();
 	// Write some ASCII datae
-	serialPort0.Write("Hello");
+	serialPort.Write("Hello");
 	// Read some data back
 	std::string readData;
-	serialPort0.Read(readData);
+	serialPort.Read(readData);
 	// Close the serial port
-	serialPort0.Close();
+	serialPort.Close();
 }
 ```
@@ -15,27 +15,66 @@
 #include <string>
 #include <fstream> // For file I/O (reading/writing to COM port)
 #include <sstream>
-#include <termios.h> // POSIX terminal control definitions (struct termios)
+// #include <termios.h> // POSIX terminal control definitions (struct termios)
+// #include <asm/termios.h> // Terminal control definitions (struct termios)
 #include <vector>
+#include <asm/ioctls.h>
+#include <asm/termbits.h>
 // User headers
 #include "Exception.hpp"
+
+ typedef unsigned int speed_t;
+// typedef struct termios2 {
+// 	tcflag_t c_iflag;		/* input mode flags */
+// 	tcflag_t c_oflag;		/* output mode flags */
+// 	tcflag_t c_cflag;		/* control mode flags */
+// 	tcflag_t c_lflag;		/* local mode flags */
+// 	cc_t c_line;			/* line discipline */
+// 	cc_t c_cc[NCCS];		/* control characters */
+// 	speed_t c_ispeed;		/* input speed */
+// 	speed_t c_ospeed;		/* output speed */
+// } termios2_t;
+
 namespace mn {
     namespace CppLinuxSerial {
+        enum class BaudRateType {
+            STANDARD,
+            CUSTOM,
+        };
+
         /// \brief		Strongly-typed enumeration of baud rates for use with the SerialPort class
+        /// \details    Specifies all the same baud rates as UNIX, as well as B_CUSTOM to specify your
+        ///             own. See https://linux.die.net/man/3/cfsetispeed for list of supported UNIX baud rates.
         enum class BaudRate {
+            B_0,
+            B_50,
+            B_75,
+            B_110,
+            B_134,
+            B_150,
+            B_200,
+            B_300,
+            B_600,
+            B_1200,
+            B_1800,
+            B_2400,
+            B_4800,
             B_9600,
+            B_19200,
             B_38400,
             B_57600,
             B_115200,
-            CUSTOM
+            B_230400,
+            B_460800,
+            B_CUSTOM, // Placeholder 
         };
         enum class State {
             CLOSED,
-            OPEN
+            OPEN,
         };
 /// \brief		SerialPort object is used to perform rx/tx serial communication.
@@ -48,6 +87,9 @@ namespace mn {
             /// \brief		Constructor that sets up serial port with the basic (required) parameters.
             SerialPort(const std::string &device, BaudRate baudRate);
+            /// \brief		Constructor that sets up serial port with the basic (required) parameters.
+            SerialPort(const std::string &device, speed_t baudRate);
+
             //! @brief		Destructor. Closes serial port if still open.
             virtual ~SerialPort();
@@ -57,6 +99,9 @@ namespace mn {
             void SetBaudRate(BaudRate baudRate);
+            /// \brief      Allows the user to set a custom baud rate.
+            void SetBaudRate(speed_t baudRate);
+
             /// \brief      Sets the read timeout (in milliseconds)/blocking mode.
             /// \details    Only call when state != OPEN. This method manupulates VMIN and VTIME.
             /// \param      timeout_ms  Set to -1 to infinite timeout, 0 to return immediately with any data (non
@@ -92,13 +137,18 @@ namespace mn {
         private:
             /// \brief		Returns a populated termios structure for the passed in file descriptor.
-            termios GetTermios();
+            // termios GetTermios();
+
+
             /// \brief		Configures the tty device as a serial port.
             /// \warning    Device must be open (valid file descriptor) when this is called.
             void ConfigureTermios();
-            void SetTermios(termios myTermios);
+            // void SetTermios(termios myTermios);
+
+            termios2 GetTermios2();
+            void SetTermios2(termios2 tty);
             /// \brief      Keeps track of the serial port's state.
             State state_;
@@ -106,8 +156,14 @@ namespace mn {
             /// \brief      The file path to the serial port device (e.g. "/dev/ttyUSB0").
             std::string device_;
-            /// \brief      The current baud rate.
-            BaudRate baudRate_;
+            /// \brief      The type of baud rate that the user has specified.
+            BaudRateType baudRateType_;
+
+            /// \brief      The current baud rate if baudRateType_ == STANDARD.
+            BaudRate baudRateStandard_;
+
+            /// \brief      The current baud rate if baudRateType_ == CUSTOM.
+            speed_t baudRateCustom_;
             /// \brief		The file descriptor for the open file. This gets written to when Open() is called.
             int fileDesc_;
@@ -15,20 +15,28 @@
 #include <unistd.h>  	// UNIX standard function definitions
 #include <fcntl.h>   	// File control definitions
 #include <errno.h>   	// Error number definitions
-#include <termios.h> 	// POSIX terminal control definitions (struct termios)
+// #include <termios.h> 	// POSIX terminal control definitions (struct termios)
 #include <system_error>	// For throwing std::system_error
+#include <sys/ioctl.h> // Used for TCGETS2, which is required for custom baud rates
+#include <cassert>
+// #include <asm/termios.h> // Terminal control definitions (struct termios)
+#include <asm/ioctls.h>
+#include <asm/termbits.h>
 // User includes
 #include "CppLinuxSerial/Exception.hpp"
 #include "CppLinuxSerial/SerialPort.hpp"
+#define    BOTHER 0010000
+
 namespace mn {
 namespace CppLinuxSerial {
 	SerialPort::SerialPort() {
         echo_ = false;
         timeout_ms_ = defaultTimeout_ms_;
-        baudRate_ = defaultBaudRate_;
+		baudRateType_ = BaudRateType::STANDARD;
+        baudRateStandard_ = defaultBaudRate_;
         readBufferSize_B_ = defaultReadBufferSize_B_;
         readBuffer_.reserve(readBufferSize_B_);
 		state_ = State::CLOSED;
@@ -37,7 +45,15 @@ namespace CppLinuxSerial {
 	SerialPort::SerialPort(const std::string& device, BaudRate baudRate) :
             SerialPort() {
 		device_ = device;
-        baudRate_ = baudRate;
+		baudRateType_ = BaudRateType::STANDARD;
+        baudRateStandard_ = baudRate;
+	}
+
+	SerialPort::SerialPort(const std::string& device, speed_t baudRate) :
+            SerialPort() {
+		device_ = device;
+		baudRateType_ = BaudRateType::CUSTOM;
+        baudRateCustom_ = baudRate;
 	}
 	SerialPort::~SerialPort() {
@@ -52,13 +68,21 @@ namespace CppLinuxSerial {
 	void SerialPort::SetDevice(const std::string& device) {
 		device_ = device;
         if(state_ == State::OPEN)
-
-
-        ConfigureTermios();
+        	ConfigureTermios();
 	}
 	void SerialPort::SetBaudRate(BaudRate baudRate)	{
-		baudRate_ = baudRate;
+		std::cout << "standard called\n";
+		baudRateType_ = BaudRateType::STANDARD;
+		baudRateStandard_ = baudRate;
+        if(state_ == State::OPEN)
+            ConfigureTermios();
+	}
+
+	void SerialPort::SetBaudRate(speed_t baudRate)	{
+		std::cout << " custom called\n";
+		baudRateType_ = BaudRateType::CUSTOM;
+		baudRateCustom_ = baudRate;
         if(state_ == State::OPEN)
             ConfigureTermios();
 	}
@@ -66,7 +90,7 @@ namespace CppLinuxSerial {
 	void SerialPort::Open()
 	{
-		std::cout << "Attempting to open COM port \"" << device_ << "\"." << std::endl;
+		// std::cout << "Attempting to open COM port \"" << device_ << "\"." << std::endl;
 		if(device_.empty()) {
 			THROW_EXCEPT("Attempted to open file when file path has not been assigned to.");
@@ -86,7 +110,7 @@ namespace CppLinuxSerial {
         ConfigureTermios();
-		std::cout << "COM port opened successfully." << std::endl;
+		// std::cout << "COM port opened successfully." << std::endl;
         state_ = State::OPEN;
 	}
@@ -97,11 +121,12 @@ namespace CppLinuxSerial {
 	void SerialPort::ConfigureTermios()
 	{
-		std::cout << "Configuring COM port \"" << device_ << "\"." << std::endl;
+		// std::cout << "Configuring COM port \"" << device_ << "\"." << std::endl;
 		//================== CONFIGURE ==================//
-		termios tty = GetTermios();
+		// termios tty = GetTermios();
+		termios2 tty = GetTermios2();
 		//================= (.c_cflag) ===============//
@@ -115,29 +140,134 @@ namespace CppLinuxSerial {
         //===================== BAUD RATE =================//
-        switch(baudRate_) {
-            case BaudRate::B_9600:
-                cfsetispeed(&tty, B9600);
-                cfsetospeed(&tty, B9600);
-                break;
-            case BaudRate::B_38400:
-                cfsetispeed(&tty, B38400);
-                cfsetospeed(&tty, B38400);
-                break;
-            case BaudRate::B_57600:
-                cfsetispeed(&tty, B57600);
-                cfsetospeed(&tty, B57600);
-                break;
-            case BaudRate::B_115200:
-                cfsetispeed(&tty, B115200);
-                cfsetospeed(&tty, B115200);
-                break;
-            case BaudRate::CUSTOM:
-                // See https://gist.github.com/kennethryerson/f7d1abcf2633b7c03cf0
-                throw std::runtime_error("Custom baud rate not yet supported.");
-            default:
-                throw std::runtime_error(std::string() + "baudRate passed to " + __PRETTY_FUNCTION__ + " unrecognized.");
-        }
+		// We used to use cfsetispeed() cand cfsetospeed(), but this didn't allow
+		// us to set custom baud rates
+		if (baudRateType_ == BaudRateType::STANDARD) {
+			switch(baudRateStandard_) {
+				// case BaudRate::B_0:
+					// cfsetispeed(&tty, B0);
+					// cfsetospeed(&tty, B0);
+				// 	tty.c_ispeed = 0;
+				// 	tty.c_ospeed = 0;
+				// 	break;
+				// case BaudRate::B_50:
+					// cfsetispeed(&tty, B50);
+					// cfsetospeed(&tty, B50);
+					// tty.c_ispeed = 50;
+					// tty.c_ospeed = 50;
+					// break;
+				// case BaudRate::B_75:
+				//     cfsetispeed(&tty, B75);
+				//     cfsetospeed(&tty, B75);
+				//     break;
+				// case BaudRate::B_110:
+				//     cfsetispeed(&tty, B110);
+				//     cfsetospeed(&tty, B110);
+				//     break;
+				// case BaudRate::B_134:
+				//     cfsetispeed(&tty, B134);
+				//     cfsetospeed(&tty, B134);
+				//     break;
+				// case BaudRate::B_150:
+				//     cfsetispeed(&tty, B150);
+				//     cfsetospeed(&tty, B150);
+				//     break;
+				// case BaudRate::B_200:
+				//     cfsetispeed(&tty, B200);
+				//     cfsetospeed(&tty, B200);
+				//     break;
+				// case BaudRate::B_300:
+				//     cfsetispeed(&tty, B300);
+				//     cfsetospeed(&tty, B300);
+				//     break;
+				// case BaudRate::B_600:
+				//     cfsetispeed(&tty, B600);
+				//     cfsetospeed(&tty, B600);
+				//     break;
+				// case BaudRate::B_1200:
+				//     cfsetispeed(&tty, B1200);
+				//     cfsetospeed(&tty, B1200);
+				//     break;
+				// case BaudRate::B_1800:
+				//     cfsetispeed(&tty, B1800);
+				//     cfsetospeed(&tty, B1800);
+				//     break;
+				// case BaudRate::B_2400:
+				//     cfsetispeed(&tty, B2400);
+				//     cfsetospeed(&tty, B2400);
+				//     break;
+				// case BaudRate::B_4800:
+				//     cfsetispeed(&tty, B4800);
+				//     cfsetospeed(&tty, B4800);
+				//     break;
+				// case BaudRate::B_9600:
+					// cfsetispeed(&tty, B9600);
+					// cfsetospeed(&tty, B9600);
+					// tty.c_ispeed = 9600;
+					// tty.c_ospeed = 9600;
+					// break;
+				// case BaudRate::B_19200:
+				//     cfsetispeed(&tty, B19200);
+				//     cfsetospeed(&tty, B19200);
+				//     break;
+				// case BaudRate::B_38400:
+				//     cfsetispeed(&tty, B38400);
+				//     cfsetospeed(&tty, B38400);
+				//     break;
+				// case BaudRate::B_57600:
+				//     cfsetispeed(&tty, B57600);
+				//     cfsetospeed(&tty, B57600);
+				//     break;
+				// case BaudRate::B_115200:
+				//     cfsetispeed(&tty, B115200);
+				//     cfsetospeed(&tty, B115200);
+				//     break;
+				// case BaudRate::B_230400:
+				//     cfsetispeed(&tty, B230400);
+				//     cfsetospeed(&tty, B230400);
+				//     break;
+				// case BaudRate::B_460800:
+				//     cfsetispeed(&tty, B460800);
+				//     cfsetospeed(&tty, B460800);
+				//     break;
+				// case BaudRate::CUSTOM:
+				//     // See https://gist.github.com/kennethryerson/f7d1abcf2633b7c03cf0
+				//     throw std::runtime_error("Custom baud rate not yet supported.");
+				default:
+					throw std::runtime_error(std::string() + "baudRate passed to " + __PRETTY_FUNCTION__ + " unrecognized.");
+			}
+		}
+		else if (baudRateType_ == BaudRateType::CUSTOM)
+		{ 
+			tty.c_cflag &= ~CBAUD;
+			tty.c_cflag |= CBAUDEX;
+			// tty.c_cflag |= BOTHER;
+			tty.c_ispeed = baudRateCustom_;
+			tty.c_ospeed = baudRateCustom_;
+
+
+			// #include <linux/serial.h>
+			// // configure port to use custom speed instead of 38400
+			// struct serial_struct ss; 
+			// ioctl(fileDesc_, TIOCGSERIAL, &ss);
+			// ss.flags = (ss.flags & ~ASYNC_SPD_MASK) | ASYNC_SPD_CUST;
+			// ss.custom_divisor = (ss.baud_base + (baudRateCustom_ / 2)) / baudRateCustom_;
+			// int closestSpeed = ss.baud_base / ss.custom_divisor;
+
+			// if (closestSpeed < baudRateCustom_ * 98 / 100 || closestSpeed > baudRateCustom_ * 102 / 100) {
+			// 	printf("Cannot set serial port speed to %d. Closest possible is %d\n", baudRateCustom_, closestSpeed);
+			// }
+
+			// ioctl(fileDesc_, TIOCSSERIAL, &ss);
+
+			// cfsetispeed(&tty, B38400);
+			// cfsetospeed(&tty, B38400);
+		}
+		else 
+		{
+			// Should never get here, bug in this libraries code!
+			assert(false);
+		}
 		//===================== (.c_oflag) =================//
@@ -193,7 +323,8 @@ namespace CppLinuxSerial {
 		// Try and use raw function call
 		//cfmakeraw(&tty);
-		this->SetTermios(tty);
+		// this->SetTermios(tty);
+		this->SetTermios2(tty);
 		/*
 		// Flush port, then apply attributes
@@ -262,39 +393,60 @@ namespace CppLinuxSerial {
 		// If code reaches here, read must of been successful
 	}
-	termios SerialPort::GetTermios() {
-        if(fileDesc_ == -1)
-            throw std::runtime_error("GetTermios() called but file descriptor was not valid.");
+	// termios SerialPort::GetTermios() {
+    //     if(fileDesc_ == -1)
+    //         throw std::runtime_error("GetTermios() called but file descriptor was not valid.");
-		struct termios tty;
-		memset(&tty, 0, sizeof(tty));
+	// 	struct termios tty;
+	// 	memset(&tty, 0, sizeof(tty));
-		// Get current settings (will be stored in termios structure)
-		if(tcgetattr(fileDesc_, &tty) != 0)
-		{
-			// Error occurred
-			std::cout << "Could not get terminal attributes for \"" << device_ << "\" - " << strerror(errno) << std::endl;
-			throw std::system_error(EFAULT, std::system_category());
-			//return false;
-		}
+	// 	// Get current settings (will be stored in termios structure)
+	// 	if(tcgetattr(fileDesc_, &tty) != 0)
+	// 	{
+	// 		// Error occurred
+	// 		std::cout << "Could not get terminal attributes for \"" << device_ << "\" - " << strerror(errno) << std::endl;
+	// 		throw std::system_error(EFAULT, std::system_category());
+	// 		//return false;
+	// 	}
-		return tty;
-	}
+	// 	return tty;
+	// }
-	void SerialPort::SetTermios(termios myTermios)
-	{
-		// Flush port, then apply attributes
-		tcflush(fileDesc_, TCIFLUSH);
+	// void SerialPort::SetTermios(termios myTermios)
+	// {
+	// 	// Flush port, then apply attributes
+	// 	tcflush(fileDesc_, TCIFLUSH);
-		if(tcsetattr(fileDesc_, TCSANOW, &myTermios) != 0)
-		{
-			// Error occurred
-			std::cout << "Could not apply terminal attributes for \"" << device_ << "\" - " << strerror(errno) << std::endl;
-			throw std::system_error(EFAULT, std::system_category());
+	// 	if(tcsetattr(fileDesc_, TCSANOW, &myTermios) != 0)
+	// 	{
+	// 		// Error occurred
+	// 		std::cout << "Could not apply terminal attributes for \"" << device_ << "\" - " << strerror(errno) << std::endl;
+	// 		throw std::system_error(EFAULT, std::system_category());
-		}
+	// 	}
+
+	// 	// Successful!
+	// }
-		// Successful!
+	termios2 SerialPort::GetTermios2()
+	{
+		struct termios2 term2;
+ 
+        ioctl(fileDesc_, TCGETS2, &term2);
+
+		return term2;
+ 
+        // term2.c_cflag &= ~CBAUD;  /* Remove current BAUD rate */
+        // term2.c_cflag |= BOTHER;  /* Allow custom BAUD rate using int input */
+        // term2.c_ispeed = speed;   /* Set the input BAUD rate */
+        // term2.c_ospeed = speed;   /* Set the output BAUD rate */
+ 
+        // ioctl(fd, TCSETS2, &term2);
+	}
+
+	void SerialPort::SetTermios2(termios2 tty)
+	{
+		ioctl(fileDesc_, TCSETS2, &tty);
 	}
     void SerialPort::Close() {
+/*
+  AnalogReadSerial
+
+  Reads an analog input on pin 0, prints the result to the Serial Monitor.
+  Graphical representation is available using Serial Plotter (Tools > Serial Plotter menu).
+  Attach the center pin of a potentiometer to pin A0, and the outside pins to +5V and ground.
+
+  This example code is in the public domain.
+
+  http://www.arduino.cc/en/Tutorial/AnalogReadSerial
+*/
+
+// the setup routine runs once when you press reset:
+void setup() {
+  // initialize serial communication at 9600 bits per second:
+  Serial.begin(13000);
+//  Serial.begin(81234); // Used to test custom baud rates
+}
+
+// the loop routine runs over and over again forever:
+void loop() {
+  Serial.println("Hello");
+  delay(100);        // delay in between reads for stability
+}
+#include <CppLinuxSerial/SerialPort.hpp>
+
+using namespace mn::CppLinuxSerial;
+
+int main() {
+	// Create serial port object and open serial port
+    // SerialPort serialPort("/dev/ttyACM0", BaudRate::B_9600);
+	SerialPort serialPort("/dev/ttyACM0", 13000);
+    serialPort.SetTimeout(-1); // Block when reading until any data is received
+	serialPort.Open();
+
+	// Write some ASCII datae
+	// serialPort0.Write("Hello");
+
+	// Read some data back
+    while(1) {
+        std::string readData;
+        serialPort.Read(readData);
+        std::cout << "Received data: " << readData;
+    }
+
+	// Close the serial port
+	serialPort.Close();
+}
 \ No newline at end of file