First commit

diygeiger.c

@@ -0,0 +1,52 @@
+#include "diygeiger.h"
+
+int diy_open(const char *device) {
+	int fd = -1;
+	struct termios tio;
+
+	memset(&tio, 0, sizeof(struct termios));
+	tio.c_cflag = CS8 | CREAD | CLOCAL;		// 8n1
+	tio.c_cc[VMIN] = 0;
+	tio.c_cc[VTIME] = 5;
+
+	if ((fd = open(device, O_RDWR)) != -1) {
+		if (cfsetspeed(&tio, B9600) == 0)		// 9600 baud
+			if (tcsetattr(fd, TCSANOW, &tio) == 0)
+				// Return file descriptor,
+				return fd;
+
+		// ... otherwise close device.
+		close(fd);
+		fd = -1;
+	}
+
+	return fd;
+}
+
+void diy_close(int device) {
+	close(device);
+}
+
+int diy_get_cpm(int device) {
+	char buf[13] = { 0 };
+
+	// Arduino sends 10-digit decimal number (unsigned long) plus tailing "\r\n".
+	diy_read(device, buf, 12);
+
+	return atoi(buf);
+}
+
+int diy_read(int device, char *buf, unsigned int len) {
+	unsigned int n;
+	ssize_t rcvd = 0;
+	char *inp = &buf[0];
+
+	for (n = 0; n < len; n++) {
+		rcvd += read(device, inp, 1);
+		inp = &buf[rcvd];
+		if (rcvd >= len)
+			break;
+	}
+
+	return rcvd;
+}