garreset: for un-shooting your gps18 in the foot. ;)

2 files changed, 37 insertions, 0 deletions

diff --git a/contrib/README b/contrib/README
index 4432ac42..12af0b7d 100644
--- a/contrib/README
+++ b/contrib/README
@@ -51,3 +51,6 @@ screen plugged in and configured to work with lcdproc).
 lla2ecef transforms latitude/longitude/altitude (aka north-east-up or local
 tangential plane) coordinates into the earth-centered-earth-fixed frame. If
 invoked as "ecef2lla" it will transform coordinates in the opposite manner.
+
+garreset attempts to force a garmin receiver back to NMEA mode - useful for
+recovering a receiver after sending the wrong configuration message.
diff --git a/contrib/garreset.c b/contrib/garreset.c
new file mode 100644
index 00000000..ecbc4c95
--- /dev/null
+++ b/contrib/garreset.c
@@ -0,0 +1,34 @@
+#include <sys/types.h>
+#include <sys/termios.h>
+#include <err.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+char pkt[] = {0x10, 0x0a, 0x02, 0x26, 0x00, 0xce, 0x10, 0x03};
+int speeds[] = {2400, 4800, 9600, 19200, 38400, 57600, 115200};
+
+int
+main(int argc, char **argv){
+	int fd, i, n;
+	struct termios t;
+
+	if ((fd = open(argv[1], O_RDWR | O_EXCL | O_NONBLOCK, 0600)) == -1)
+		err(1, "open");
+
+	n = sizeof(speeds) / sizeof(speeds[0]);
+	for(i = 0; i < n; i++){
+		tcgetattr(fd, &t);
+		cfmakeraw(&t);
+		cfsetspeed(&t, speeds[i]);
+		tcsetattr(fd, TCSANOW | TCSAFLUSH, &t);
+		fprintf(stderr, "%d ", speeds[i]);
+		if (write(fd, pkt, sizeof(pkt)) != sizeof(pkt))
+			err(1, "write");
+		tcdrain(fd);
+		usleep(333333);
+	}
+	fprintf(stderr, "done.\n");
+	close(fd);
+}