ref: ef6ce918c04fc82bea759fd843cc09e273ec9f6c
dir: /appl/demo/lego/clockface.b/
# Model 1
implement Clockface;
include "sys.m";
include "draw.m";
Clockface : module {
init : fn (ctxt : ref Draw->Context, argv : list of string);
};
sys : Sys;
hmpath : con "motor/0"; # hour-hand motor
mmpath : con "motor/2"; # minute-hand motor
allmpath : con "motor/012"; # all motors (for stopall msg)
hbpath : con "sensor/0"; # hour-hand sensor
mbpath : con "sensor/2"; # minute-hand sensor
lspath: con "sensor/1"; # light sensor;
ONTHRESH : con 780; # light sensor thresholds
OFFTHRESH : con 740;
NCLICKS : con 120;
MINCLICKS : con 2; # min number of clicks required to stop a motor
Hand : adt {
motor : ref Sys->FD;
sensor : ref Sys->FD;
fwd : array of byte;
rev : array of byte;
stop : array of byte;
pos : int;
};
lightsensor : ref Sys->FD;
allmotors : ref Sys->FD;
hourhand : ref Hand;
minutehand : ref Hand;
reqch: chan of (string, chan of int);
init(nil : ref Draw->Context, argv : list of string)
{
sys = load Sys Sys->PATH;
sys->pctl(Sys->NEWPGRP, nil);
argv = tl argv;
if (len argv != 1) {
sys->print("usage: lego_dir\n");
raise("fail:usage");
}
# set up our control file
if (sys->bind("#s", ".", Sys->MBEFORE) == -1) {
sys->print("failed to bind srv device: %r\n");
return;
}
f2c := sys->file2chan(".", "clockface");
if (f2c == nil) {
sys->print("cannot create legolink channel: %r\n");
return;
}
legodir := hd argv;
if (legodir[len legodir -1] != '/')
legodir[len legodir] = '/';
# get the motor files
sys->print("opening motor files\n");
hm := sys->open(legodir + hmpath, Sys->OWRITE);
mm := sys->open(legodir +mmpath, Sys->OWRITE);
allmotors = sys->open(legodir + allmpath, Sys->OWRITE);
if (hm == nil || mm == nil || allmotors == nil) {
sys->print("cannot open motor files\n");
raise("fail:error");
}
# get the sensor files
sys->print("opening sensor files\n");
hb := sys->open(legodir + hbpath, Sys->ORDWR);
mb := sys->open(legodir + mbpath, Sys->ORDWR);
lightsensor = sys->open(legodir + lspath, Sys->ORDWR);
if (hb == nil || mb == nil) {
sys->print("cannot open sensor files\n");
raise("fail:error");
}
hourhand = ref Hand(hm, hb, array of byte "f7", array of byte "r7", array of byte "s7", 0);
minutehand = ref Hand(mm, mb, array of byte "f7", array of byte "r7", array of byte "s7", 0);
sys->print("setting sensor types\n");
setsensortypes(hourhand, minutehand, lightsensor);
reqch = chan of (string, chan of int);
spawn sethands();
# reqch <-= ("reset", nil);
spawn srvlink(f2c);
}
srvlink(f2c : ref Sys->FileIO)
{
for (;;) alt {
(offset, count, fid, rc) := <- f2c.read =>
if (rc == nil)
continue;
if (offset != 0) {
rc <-= (nil, nil);
continue;
}
rc <- = (array of byte gettime(), nil);
(offset, data, fid, wc) := <- f2c.write =>
if (wc == nil)
continue;
if (offset != 0) {
wc <-= (0, "bad offset");
continue;
}
spawn settime(wc, string data, len data);
}
}
gettime(): string
{
hpos := hourhand.pos;
mpos := minutehand.pos;
h := 12 * hpos / NCLICKS;
m := 60 * mpos / NCLICKS;
time := "??:??";
for (hadj := -1; hadj <= 1; hadj++) {
hpos2 := (((h+hadj) * NCLICKS) / 12) + ((m * NCLICKS) / (12 * 60));
dhpos := hpos - hpos2;
if (dhpos >= -2 && dhpos <= 2) {
# allow 2 clicks of imprecision either way
time = sys->sprint("%.2d:%.2d", h+hadj, m);
break;
}
}
return sys->sprint("%s %d %d", time, hpos*360/NCLICKS, mpos*360/NCLICKS);
}
settime(wc: Sys->Rwrite, time: string, wn: int)
{
done := chan of int;
reqch <-= (time, done);
<- done;
wc <-= (wn, nil);
}
str2clicks(s : string) : (int, int)
{
h, m : int = 0;
(n, toks) := sys->tokenize(s, ":");
if (n > 1) {
h = int hd toks;
toks = tl toks;
n--;
}
if (n > 0) {
m = int hd toks;
}
h = ((h * NCLICKS) / 12) + ((m * NCLICKS) / (12 * 60));
m = (m * NCLICKS)/60;
return (h, m);
}
sethands()
{
for (;;) {
(time, rc) := <- reqch;
if (time == "reset" || time == "reset\n") {
reset();
time = "12:00";
}
(hclk, mclk) := str2clicks(time);
for (i := 0; i < 6; i++) {
hdelta := clickdistance(hourhand.pos, hclk, NCLICKS);
mdelta := clickdistance(minutehand.pos, mclk, NCLICKS);
if (hdelta == 0 && mdelta == 0)
break;
if (hdelta != 0)
sethand(hourhand, hdelta);
if (mdelta != 0)
sethand(minutehand, mdelta);
}
releaseall();
if (rc != nil)
rc <- = 1;
}
}
clickdistance(start, stop, mod : int) : int
{
if (start > stop)
stop += mod;
d := (stop - start) % mod;
if (d > mod/2)
d -= mod;
return d;
}
setsensortypes(h1, h2 : ref Hand, ls : ref Sys->FD)
{
button := array of byte "b0";
light := array of byte "l0";
sys->seek(h1.sensor, big 0, Sys->SEEKSTART);
sys->write(h1.sensor, button, len button);
sys->seek(h2.sensor, big 0, Sys->SEEKSTART);
sys->write(h2.sensor, button, len button);
sys->seek(ls, big 0, Sys->SEEKSTART);
sys->write(ls, light, len light);
}
HOUR_ADJUST : con 1;
MINUTE_ADJUST : con 3;
reset()
{
# run the motors until hands are well away from 12 o'clock (below threshold)
setsensortypes(hourhand, minutehand, lightsensor);
val := readsensor(lightsensor);
if (val > OFFTHRESH) {
triggered := chan of int;
sys->print("wait for hands clear of light sensor\n");
spawn lightwait(triggered, lightsensor, 0);
forward(minutehand);
reverse(hourhand);
val = <- triggered;
stopall();
sys->print("sensor %d\n", val);
}
resethand(hourhand);
hourhand.pos += HOUR_ADJUST;
resethand(minutehand);
minutehand.pos += MINUTE_ADJUST;
}
sethand(hand : ref Hand, delta : int)
{
triggered := chan of int;
dir := 1;
if (delta < 0) {
dir = -1;
delta = -delta;
}
if (delta > MINCLICKS) {
spawn handwait(triggered, hand, delta - MINCLICKS);
if (dir > 0)
forward(hand);
else
reverse(hand);
<- triggered;
stop(hand);
hand.pos += dir * readsensor(hand.sensor);
} else {
startval := readsensor(hand.sensor);
if (dir > 0)
forward(hand);
else
reverse(hand);
stop(hand);
hand.pos += dir * (readsensor(hand.sensor) - startval);
}
if (hand.pos < 0)
hand.pos += NCLICKS;
hand.pos %= NCLICKS;
}
resethand(hand : ref Hand)
{
triggered := chan of int;
val : int;
# run the hand until the light sensor is above threshold
sys->print("running hand until light sensor activated\n");
spawn lightwait(triggered, lightsensor, 1);
forward(hand);
val = <- triggered;
stop(hand);
sys->print("sensor %d\n", val);
startclick := readsensor(hand.sensor);
# advance until light sensor drops below threshold
sys->print("running hand until light sensor clear\n");
spawn lightwait(triggered, lightsensor, 0);
forward(hand);
val = <- triggered;
stop(hand);
sys->print("sensor %d\n", val);
stopclick := readsensor(hand.sensor);
nclicks := stopclick - startclick;
sys->print("startpos %d, endpos %d (nclicks %d)\n", startclick, stopclick, nclicks);
hand.pos = nclicks/2;
}
stop(hand : ref Hand)
{
sys->seek(hand.motor, big 0, Sys->SEEKSTART);
sys->write(hand.motor, hand.stop, len hand.stop);
}
stopall()
{
msg := array of byte "s0s0s0";
sys->seek(allmotors, big 0, Sys->SEEKSTART);
sys->write(allmotors, msg, len msg);
}
releaseall()
{
msg := array of byte "F0F0F0";
sys->seek(allmotors, big 0, Sys->SEEKSTART);
sys->write(allmotors, msg, len msg);
}
forward(hand : ref Hand)
{
sys->seek(hand.motor, big 0, Sys->SEEKSTART);
sys->write(hand.motor, hand.fwd, len hand.fwd);
}
reverse(hand : ref Hand)
{
sys->seek(hand.motor, big 0, Sys->SEEKSTART);
sys->write(hand.motor, hand.rev, len hand.rev);
}
readsensor(fd : ref Sys->FD) : int
{
buf := array [4] of byte;
sys->seek(fd, big 0, Sys->SEEKSTART);
n := sys->read(fd, buf, len buf);
if (n <= 0)
return -1;
return int string buf[0:n];
}
handwait(reply : chan of int, hand : ref Hand, clicks : int)
{
blk := array of byte ("b" + string clicks);
sys->seek(hand.sensor, big 0, Sys->SEEKSTART);
sys->print("handwait(%s)\n", string blk);
if (sys->write(hand.sensor, blk, len blk) != len blk)
sys->print("handwait write error: %r\n");
reply <- = readsensor(hand.sensor);
}
lightwait(reply : chan of int, fd : ref Sys->FD, on : int)
{
thresh := "";
if (on)
thresh = "l>" + string ONTHRESH;
else
thresh = "l<" + string OFFTHRESH;
blk := array of byte (thresh);
sys->print("lightwait(%s)\n", string blk);
sys->seek(fd, big 0, Sys->SEEKSTART);
sys->write(fd, blk, len blk);
reply <- = readsensor(fd);
}