static void
spacep(int not)
{
evenp(not);
}
int encode_cmd(char* incmd, char inlen,
char** enccmd, char* enclen) {
unsigned char i, j;
char n;
static char _enccmd[(MAXGRP / 2) + (MAXGRP % 2)];
/* Each controller requires 4-bits but each command (char)
* is 8-bits. `enclen` is the number of 4-bit (nibbles) needed
* to store `inlen` commands, possibly with a zero padded entry.
*/
*enclen = (inlen / 2) + (inlen % 2); /* each cmd is 4-bits */
*enccmd = _enccmd; /* point to our static buffer */
if (inlen > MAXGRP) {
return -1;
}
j = 0; /* enccmd index, 1/2 of incmd index (i) */
for (i = 0; i < inlen; i++) {
n = incmd[i] - 48; /* ASCII to integer */
/* only commands from 0 to 8 are allowed
* 0 : off
* 1-8 : valve on
*/
if (n > 8) {
return -2;
}
/* command, 1 group
* 7 4 3 1 0
* +--------+-------+------+
* | unused | valve | en_n |
* +--------+-------+------+
*/
if (0 == n) {
/* disable all, en_n = 1 */
n = 1;
} else {
/* valve #, 0 offset, en_n = 0 */
n = (n - 1) << 1;
}
/* save this command to a nibble */
if (evenp(i)) {
/* MSB first, first in daisy chain gets last (lowest) bits */
(*enccmd)[j] = (0x0F & n);
} else {
/* MSB first, second in daisy chain gets first (highest) bits */
(*enccmd)[j] |= (n << 4);
j++;
}
}
/* reverse bytes */
for (i = 0; i < ((*enclen) / 2); i++) {
n = (*enccmd)[i];
(*enccmd)[i] = (*enccmd)[((*enclen) - 1) - i];
(*enccmd)[((*enclen) - 1) - i] = n;
}
return 0;
}
