float SHT15::get (unsigned short int mode) {
unsigned short int error;
unsigned short int hraw, traw;
float h, hq, t, d, ld;
if ((error = getraw (&traw, 0)) != 0) return (float) error;
if ((error = getraw (&hraw, 1)) != 0) return (float) error;
h = (float) hraw;
t = -40.1 + 0.01 * ((float) traw); // 14 bit, 'C
if (mode == 0) return t;
hq = -2.0468 + 0.0367 * h - 1.5955E-6 * h * h;
h = (t - 25) * (0.01 + 0.00008 * h) + hq;
h = h < 0.1 ? 0.1 : (h > 100 ? 100 : h);
if (mode == 1) return h;
ld = (log10(h) - 2) / 0.4343 + (17.62 * t) / (243.12 + t);
d = 243.12 * ld / (17.62 - ld);
return d;
}
static fn_t *fn_realize(struct fnparse *fnparse, eh_t *eh) {
// this is a bit tricky since fn and p->fn share memory
fn_t *fn = (fn_t *)fnparse;
tbl_t *vars = fnparse->vars;
tbl_t *fns = fnparse->fns;
fn->vcount = vars->len;
fn->fcount = fns->len;
fn->stack = 25; // TODO make this reasonable
fn->vars = mu_alloc(fn->vcount*sizeof(var_t) +
fn->fcount*sizeof(fn_t *), eh);
tbl_for_begin (k, v, vars) {
fn->vars[getraw(v)] = k;
} tbl_for_end;
int i = 0;
fn->fns = (fn_t**)&fn->vars[fn->vcount];
tbl_for_begin (k, v, fns) {
fn->fns[i++] = (fn_t*)getraw(v);
} tbl_for_end;
bool
get_temperature(const char *ds_name, double *temp)
{
char pathbuf[BUFSIZ];
char *eptr, *chp;
snprintf(pathbuf, sizeof pathbuf, "/sys/bus/w1/devices/%s/w1_slave", ds_name);
if ((chp = getraw(pathbuf)) == NULL) {
MQTT_log("Failed to read %s %s\n", pathbuf, strerror(errno));
return (false);
}
*temp = (double) ((double)strtol(chp, &eptr, 10)/1000.00);
return (true);
}
