+#!/usr/bin/nickle
+
+import File;
+
+string timed_read(file f, int timeout) {
+ thread reader = fork func() {
+ try {
+ return fgets(f);
+ } catch Thread::signal(int i) {
+ return "";
+ }
+ }();
+
+ thread killer = fork func() {
+ try {
+ sleep (timeout);
+ Thread::send_signal(reader, 1);
+ } catch Thread::signal(int i) {
+ return;
+ }
+ }();
+
+ poly v = Thread::join(reader);
+ Thread::send_signal(killer, 1);
+ Thread::join(killer);
+ if (is_string(v))
+ return v;
+ return "";
+}
+
+void flush_input(file f) {
+ for (;;) {
+ string s = timed_read(f, 200);
+ if (s == "")
+ break;
+ }
+}
+
+string[*] settings(file f) {
+ string[...] x = {};
+
+ flush_input(f);
+ fprintf (f, "c s\nv\n");
+ flush(f);
+ for (;;) {
+ string l = File::fgets(f);
+ x[dim(x)] = l;
+ if (String::index(l, "software-version") == 0)
+ break;
+ }
+ return x;
+}
+
+string[*] find_setting(string[*] s, string match) {
+ for (int i = 0; i < dim(s); i++)
+ if (String::index(s[i], match) == 0)
+ return String::split(s[i], " ");
+ return (string[*]) {};
+}
+
+bool
+do_cal(file f) {
+ flush_input(f);
+ fprintf(f, "E 1\nc a 0\n");
+ flush(f);
+ string s = "";
+ bool worked = true;
+ bool running = false;
+
+ thread put = fork func() {
+ try {
+ for (;;) {
+ putc(getchar(), f);
+ flush(f);
+ }
+ } catch Thread::signal(int i) {
+ return;
+ }
+ }();
+
+ for (;;) {
+ int c = getc(f);
+ if (c == '\n')
+ s = "";
+ else
+ s = s + String::new(c);
+ putchar(c); flush(stdout);
+ if (String::index(s, "press a key...") >= 0)
+ running = true;
+ if (String::index(s, "Invalid") >= 0)
+ worked = false;
+ if (running && String::index(s, ">") >= 0)
+ break;
+ }
+ fprintf (f, "E 0\n");
+ if (worked)
+ fprintf (f, "c w\n");
+ sleep(200);
+ Thread::send_signal(put, 1);
+ Thread::join(put);
+
+ return worked;
+}
+
+void main () {
+ string name = argv[1];
+ file f = open(name, "r+");
+
+ if (do_cal(f)) {
+ string[*] s = settings(f);
+ string[*] ac = find_setting(s, "Accel cal");
+ printf ("Calibration value +1g %s -1g %s saved\n", ac[3], ac[5]);
+ exit (0);
+ } else {
+ printf ("Calibration failed\n");
+ exit (1);
+ }
+}
+
+main();