2 * Copyright © 2009 Keith Packard <keithp@keithp.com>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; version 2 of the License.
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
20 static const int16_t altitude_table[2048] = {
25 ao_pres_to_altitude(int16_t pres) __reentrant
28 if (pres < 0) pres = 0;
29 if (pres > 2047) pres = 2047;
30 return altitude_table[pres];
34 ao_altitude_to_pres(int16_t alt) __reentrant
38 for (pres = 0; pres < 2047; pres++)
39 if (altitude_table[pres] <= alt)
44 static __xdata uint8_t ao_temp_mutex;
47 ao_temp_to_dC(int16_t temp) __reentrant
51 ao_mutex_get(&ao_temp_mutex);
52 ret = (int16_t) ((temp >> 4) * 3300L / 2047L) - 500;
53 ao_mutex_put(&ao_temp_mutex);