Avoid 16-bit overflow in velocity computation.
[fw/altos] / ao_telemetry.c
1 /*
2  * Copyright © 2009 Keith Packard <keithp@keithp.com>
3  *
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.
7  *
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.
12  *
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.
16  */
17
18 #include "ao.h"
19
20 __xdata uint16_t ao_telemetry_interval = 0;
21 __xdata uint8_t ao_rdf = 0;
22 __xdata uint16_t ao_rdf_time;
23
24 #define AO_RDF_INTERVAL AO_SEC_TO_TICKS(3)
25
26 void
27 ao_telemetry(void)
28 {
29         static __xdata struct ao_telemetry telemetry;
30
31         ao_config_get();
32         memcpy(telemetry.callsign, ao_config.callsign, AO_MAX_CALLSIGN);
33         telemetry.addr = ao_serial_number;
34         ao_rdf_time = ao_time();
35         for (;;) {
36                 while (ao_telemetry_interval == 0)
37                         ao_sleep(&ao_telemetry_interval);
38                 telemetry.flight_state = ao_flight_state;
39                 telemetry.flight_accel = ao_flight_accel;
40                 telemetry.ground_accel = ao_ground_accel;
41                 telemetry.flight_vel = ao_flight_vel;
42                 telemetry.flight_pres = ao_flight_pres;
43                 telemetry.ground_pres = ao_ground_pres;
44                 ao_adc_get(&telemetry.adc);
45                 ao_mutex_get(&ao_gps_mutex);
46                 memcpy(&telemetry.gps, &ao_gps_data, sizeof (struct ao_gps_data));
47                 ao_mutex_put(&ao_gps_mutex);
48                 ao_radio_send(&telemetry);
49                 ao_delay(ao_telemetry_interval);
50                 if (ao_rdf &&
51                     (int16_t) (ao_time() - ao_rdf_time) >= 0)
52                 {
53                         ao_rdf_time = ao_time() + AO_RDF_INTERVAL;
54                         ao_radio_rdf();
55                         ao_delay(ao_telemetry_interval);
56                 }
57         }
58 }
59
60 void
61 ao_telemetry_set_interval(uint16_t interval)
62 {
63         ao_telemetry_interval = interval;
64         ao_wakeup(&ao_telemetry_interval);
65 }
66
67 void
68 ao_rdf_set(uint8_t rdf)
69 {
70         ao_rdf = rdf;
71         if (rdf == 0)
72                 ao_radio_rdf_abort();
73 }
74
75 __xdata struct ao_task  ao_telemetry_task;
76
77 void
78 ao_telemetry_init()
79 {
80         ao_add_task(&ao_telemetry_task, ao_telemetry, "telemetry");
81 }