src/main/io/transponder_ir.c

   1 /*
   2  * This file is part of Cleanflight and Betaflight.
   3  *
   4  * Cleanflight and Betaflight are free software. You can redistribute
   5  * this software and/or modify this software under the terms of the
   6  * GNU General Public License as published by the Free Software
   7  * Foundation, either version 3 of the License, or (at your option)
   8  * any later version.
   9  *
  10  * Cleanflight and Betaflight are distributed in the hope that they
  11  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  12  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  13  * See the GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this software.
  17  *
  18  * If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include <stdbool.h>
  22 #include <stdlib.h>
  23 #include <stdint.h>
  24 #include <string.h>
  25 #include <stdarg.h>
  26
  27 #include "platform.h"
  28
  29 #ifdef USE_TRANSPONDER
  30 #include "build/build_config.h"
  31
  32 #include "config/config_reset.h"
  33 #include "pg/pg.h"
  34 #include "pg/pg_ids.h"
  35
  36 #include "drivers/timer.h"
  37 #include "drivers/transponder_ir.h"
  38 #include "drivers/system.h"
  39 #include "drivers/usb_io.h"
  40
  41 #include "config/config.h"
  42
  43 #include "io/transponder_ir.h"
  44
  45 PG_REGISTER_WITH_RESET_FN(transponderConfig_t, transponderConfig, PG_TRANSPONDER_CONFIG, 0);
  46
  47 void pgResetFn_transponderConfig(transponderConfig_t *transponderConfig)
  48 {
  49     RESET_CONFIG_2(transponderConfig_t, transponderConfig,
  50         .provider = TRANSPONDER_ILAP,
  51         .reserved = 0,
  52         .data = { 0x12, 0x34, 0x56, 0x78, 0x9A, 0xBC, 0x0, 0x0, 0x0 }, // Note, this is NOT a valid transponder code, it's just for testing production hardware
  53         .ioTag = IO_TAG_NONE
  54     );
  55     transponderConfig->ioTag = timerioTagGetByUsage(TIM_USE_TRANSPONDER, 0);
  56 }
  57
  58 static bool transponderInitialised = false;
  59 static bool transponderRepeat = false;
  60
  61 // timers
  62 static timeUs_t nextUpdateAtUs = 0;
  63
  64 #define JITTER_DURATION_COUNT (sizeof(jitterDurations) / sizeof(uint8_t))
  65 static uint8_t jitterDurations[] = {0,9,4,8,3,9,6,7,1,6,9,7,8,2,6};
  66
  67 const transponderRequirement_t transponderRequirements[TRANSPONDER_PROVIDER_COUNT] = {
  68     {TRANSPONDER_ILAP, TRANSPONDER_DATA_LENGTH_ILAP, TRANSPONDER_TRANSMIT_DELAY_ILAP, TRANSPONDER_TRANSMIT_JITTER_ILAP},
  69     {TRANSPONDER_ARCITIMER, TRANSPONDER_DATA_LENGTH_ARCITIMER, TRANSPONDER_TRANSMIT_DELAY_ARCITIMER, TRANSPONDER_TRANSMIT_JITTER_ARCITIMER},
  70     {TRANSPONDER_ERLT, TRANSPONDER_DATA_LENGTH_ERLT, TRANSPONDER_TRANSMIT_DELAY_ERLT, TRANSPONDER_TRANSMIT_JITTER_ERLT}
  71 };
  72
  73 void transponderUpdate(timeUs_t currentTimeUs)
  74 {
  75     static uint32_t jitterIndex = 0;
  76
  77     if (!(transponderInitialised && transponderRepeat && isTransponderIrReady())) {
  78         return;
  79     }
  80
  81     const bool updateNow = (timeDelta_t)(currentTimeUs - nextUpdateAtUs) >= 0L;
  82     if (!updateNow) {
  83         return;
  84     }
  85
  86     uint8_t provider = transponderConfig()->provider;
  87
  88     // TODO use a random number generator for random jitter?  The idea here is to avoid multiple transmitters transmitting at the same time.
  89     uint32_t jitter = (transponderRequirements[provider - 1].transmitJitter / 10 * jitterDurations[jitterIndex++]);
  90     if (jitterIndex >= JITTER_DURATION_COUNT) {
  91         jitterIndex = 0;
  92     }
  93
  94     nextUpdateAtUs = currentTimeUs + transponderRequirements[provider - 1].transmitDelay + jitter;
  95
  96 #ifdef REDUCE_TRANSPONDER_CURRENT_DRAW_WHEN_USB_CABLE_PRESENT
  97     // reduce current draw when USB cable is plugged in by decreasing the transponder transmit rate.
  98     if (usbCableIsInserted()) {
  99         nextUpdateAtUs = currentTimeUs + (1000 * 1000) / 10; // 10 hz.
 100     }
 101 #endif
 102
 103     transponderIrTransmit();
 104 }
 105
 106 void transponderInit(void)
 107 {
 108     transponderInitialised = transponderIrInit(transponderConfig()->ioTag, transponderConfig()->provider);
 109     if (!transponderInitialised) {
 110         return;
 111     }
 112
 113     transponderIrUpdateData(transponderConfig()->data);
 114 }
 115
 116 void transponderStopRepeating(void)
 117 {
 118     transponderRepeat = false;
 119 }
 120
 121 void transponderStartRepeating(void)
 122 {
 123     if (!transponderInitialised) {
 124         return;
 125     }
 126
 127     transponderRepeat = true;
 128 }
 129
 130 void transponderUpdateData(void)
 131 {
 132     if (!transponderInitialised) {
 133         return;
 134     }
 135
 136     transponderIrUpdateData(transponderConfig()->data);
 137 }
 138
 139 void transponderTransmitOnce(void) {
 140
 141     if (!transponderInitialised) {
 142         return;
 143     }
 144     transponderIrTransmit();
 145 }
 146 #endif