2 * Copyright © 2014 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; either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
21 #define MUL(p,m) ((int32_t) AO_ADC_REFERENCE_DV * ((p) + (m)))
22 #define ADD(p,m) (MUL(p,m)/2)
23 #define DIV(p,m) ((int32_t) AO_ADC_MAX * (m))
24 #define scale(v,p,m) (((int32_t) (v) * MUL(p,m) + ADD(p,m)) / DIV(p,m))
26 #if HAS_APRS || HAS_BATTERY_REPORT
28 ao_battery_decivolt(int16_t adc)
30 return scale(adc, AO_BATTERY_DIV_PLUS, AO_BATTERY_DIV_MINUS);
34 #if HAS_APRS && defined(AO_IGNITE_DIV_PLUS)
36 ao_ignite_decivolt(int16_t adc)
38 return scale(adc, AO_IGNITE_DIV_PLUS, AO_IGNITE_DIV_MINUS);