TeleStern/ao-tools/lib/cc-telemetry.c

93 lines
2.0 KiB
C

/*
* Copyright © 2011 Keith Packard <keithp@keithp.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*/
#include "cc.h"
#include <string.h>
static int
parse_byte(char *data, uint8_t *byte)
{
char d[3];
int x;
d[0] = data[0];
d[1] = data[1];
d[2] = '\0';
if (sscanf(d, "%x", &x) != 1)
return FALSE;
*byte = x;
return TRUE;
}
int
cc_telemetry_parse(const char *input_line, union ao_telemetry_all *telemetry)
{
uint8_t *byte;
char *data;
uint8_t hex[35];
int i;
if (strncmp(input_line, "TELEM", 5) != 0)
return FALSE;
data = strchr (input_line, ' ');
if (!data)
return FALSE;
data++;
byte = hex;
for (i = 0; i < 35; i++) {
if (!parse_byte(data, byte))
return FALSE;
data += 2;
byte++;
}
if (hex[0] != 34)
return FALSE;
memcpy(telemetry, hex+1, 34);
return TRUE;
}
uint8_t
cc_telemetry_cksum(const union ao_telemetry_all *telemetry)
{
const uint8_t *x = (const uint8_t *) telemetry;
int i;
uint8_t sum = 0x5a;
for (i = 0; i < 34; i++)
sum += x[i];
return sum;
}
void
cc_telemetry_unparse(const union ao_telemetry_all *telemetry, char output_line[CC_TELEMETRY_BUFSIZE])
{
uint8_t hex[36];
int i;
int p;
hex[0] = 34;
memcpy(hex+1, telemetry, 34);
hex[35] = cc_telemetry_cksum(telemetry);
strcpy(output_line, "TELEM ");
p = strlen(output_line);
for (i = 0; i < 36; i++) {
sprintf(output_line + p, "%02x", hex[i]);
p += 2;
}
}