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-rw-r--r--Makefile33
-rw-r--r--serial.c85
2 files changed, 118 insertions, 0 deletions
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..2f321cd
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,33 @@
+CC = clang
+CLAGS = -Wall -g -std=c++11
+DEBUGFLAGS = -Wall -g -std=c++11
+LDFLAGS =
+BUILDDIR = build
+SOURCEDIR = src
+OBJECTDIR = obj
+
+OUTPUT = program
+
+SRCS = $(wildcard $(SOURCEDIR)/*.cpp)
+OBJS = $(SRCS:.cpp=.o)
+OBJ = $(OBJS:$(SOURCEDIR)/%=$(OBJECTDIR)/%)
+
+build: dir $(OBJ)
+ @echo [LD] $(OBJ)
+ @$(CC) $(CFLAGS) -o $(BUILDDIR)/$(OUTPUT) $(OBJ) $(LDFLAGS)
+
+dir:
+ @mkdir -p $(OBJECTDIR)
+ @mkdir -p $(BUILDDIR)
+
+$(OBJECTDIR)/%.o: $(SOURCEDIR)/%.cpp
+ @echo [CC] $<
+ @$(CC) $(CFLAGS) -c $< -o $@
+
+.PHONY: clean
+
+clean:
+ @echo [RM] $(OBJ)
+ @echo [RM] $(BUILDDIR)/$(OUTPUT)
+ @rm -df $(OBJ)
+ @rm -Rdf $(BUILDDIR) $(OBJECTDIR)
diff --git a/serial.c b/serial.c
new file mode 100644
index 0000000..63e8ba7
--- /dev/null
+++ b/serial.c
@@ -0,0 +1,85 @@
+#include <errno.h>
+#include <fcntl.h>
+#include <string.h>
+#include <termios.h>
+#include <unistd.h>
+
+int
+set_interface_attribs (int fd, int speed, int parity)
+{
+ struct termios tty;
+ memset (&tty, 0, sizeof tty);
+ if (tcgetattr (fd, &tty) != 0)
+ {
+ error_message ("error %d from tcgetattr", errno);
+ return -1;
+ }
+
+ cfsetospeed (&tty, speed);
+ cfsetispeed (&tty, speed);
+
+ tty.c_cflag = (tty.c_cflag & ~CSIZE) | CS8; // 8-bit chars
+ // disable IGNBRK for mismatched speed tests; otherwise receive break
+ // as \000 chars
+ tty.c_iflag &= ~IGNBRK; // disable break processing
+ tty.c_lflag = 0; // no signaling chars, no echo,
+ // no canonical processing
+ tty.c_oflag = 0; // no remapping, no delays
+ tty.c_cc[VMIN] = 0; // read doesn't block
+ tty.c_cc[VTIME] = 5; // 0.5 seconds read timeout
+
+ tty.c_iflag &= ~(IXON | IXOFF | IXANY); // shut off xon/xoff ctrl
+
+ tty.c_cflag |= (CLOCAL | CREAD);// ignore modem controls,
+ // enable reading
+ tty.c_cflag &= ~(PARENB | PARODD); // shut off parity
+ tty.c_cflag |= parity;
+ tty.c_cflag &= ~CSTOPB;
+ tty.c_cflag &= ~CRTSCTS;
+
+ if (tcsetattr (fd, TCSANOW, &tty) != 0)
+ {
+ error_message ("error %d from tcsetattr", errno);
+ return -1;
+ }
+ return 0;
+}
+
+void
+set_blocking (int fd, int should_block)
+{
+ struct termios tty;
+ memset (&tty, 0, sizeof tty);
+ if (tcgetattr (fd, &tty) != 0)
+ {
+ error_message ("error %d from tggetattr", errno);
+ return;
+ }
+
+ tty.c_cc[VMIN] = should_block ? 1 : 0;
+ tty.c_cc[VTIME] = 5; // 0.5 seconds read timeout
+
+ if (tcsetattr (fd, TCSANOW, &tty) != 0)
+ error_message ("error %d setting term attributes", errno);
+}
+
+
+...
+char *portname = "/dev/ttyUSB1"
+ ...
+int fd = open (portname, O_RDWR | O_NOCTTY | O_SYNC);
+if (fd < 0)
+{
+ error_message ("error %d opening %s: %s", errno, portname, strerror (errno));
+ return;
+}
+
+set_interface_attribs (fd, B115200, 0); // set speed to 115,200 bps, 8n1 (no parity)
+set_blocking (fd, 0); // set no blocking
+
+write (fd, "hello!\n", 7); // send 7 character greeting
+
+usleep ((7 + 25) * 100); // sleep enough to transmit the 7 plus
+ // receive 25: approx 100 uS per char transmit
+char buf [100];
+int n = read (fd, buf, sizeof buf); // read up to 100 characters if ready to read