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 "common/utils.h"
  37
  38 #include "drivers/timer.h"
  39 #include "drivers/transponder_ir.h"
  40 #include "drivers/system.h"
  41 #include "drivers/usb_io.h"
  42
  43 #include "config/config.h"
  44
  45 #include "io/transponder_ir.h"
  46
  47 PG_REGISTER_WITH_RESET_FN(transponderConfig_t, transponderConfig, PG_TRANSPONDER_CONFIG, 0);
  48
  49 void pgResetFn_transponderConfig(transponderConfig_t *transponderConfig)
  50 {
  51     RESET_CONFIG_2(transponderConfig_t, transponderConfig,
  52         .provider = TRANSPONDER_ILAP,
  53         .reserved = 0,
  54         .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
  55         .ioTag = IO_TAG_NONE
  56     );
  57 #ifdef TRANSPONDER_PIN
  58     transponderConfig->ioTag = IO_TAG(TRANSPONDER_PIN);
  59 #else
  60     transponderConfig->ioTag = IO_TAG_NONE;
  61 #endif
  62 }
  63
  64 static bool transponderInitialised = false;
  65 static bool transponderRepeat = false;
  66
  67 // timers
  68 static timeUs_t nextUpdateAtUs = 0;
  69
  70 #define JITTER_DURATION_COUNT ARRAYLEN(jitterDurations)
  71 static uint8_t jitterDurations[] = {0,9,4,8,3,9,6,7,1,6,9,7,8,2,6};
  72
  73 const transponderRequirement_t transponderRequirements[TRANSPONDER_PROVIDER_COUNT] = {
  74     {TRANSPONDER_ILAP, TRANSPONDER_DATA_LENGTH_ILAP, TRANSPONDER_TRANSMIT_DELAY_ILAP, TRANSPONDER_TRANSMIT_JITTER_ILAP},
  75     {TRANSPONDER_ARCITIMER, TRANSPONDER_DATA_LENGTH_ARCITIMER, TRANSPONDER_TRANSMIT_DELAY_ARCITIMER, TRANSPONDER_TRANSMIT_JITTER_ARCITIMER},
  76     {TRANSPONDER_ERLT, TRANSPONDER_DATA_LENGTH_ERLT, TRANSPONDER_TRANSMIT_DELAY_ERLT, TRANSPONDER_TRANSMIT_JITTER_ERLT}
  77 };
  78
  79 void transponderUpdate(timeUs_t currentTimeUs)
  80 {
  81     static uint32_t jitterIndex = 0;
  82
  83     if (!(transponderInitialised && transponderRepeat && isTransponderIrReady())) {
  84         return;
  85     }
  86
  87     const bool updateNow = (timeDelta_t)(currentTimeUs - nextUpdateAtUs) >= 0L;
  88     if (!updateNow) {
  89         return;
  90     }
  91
  92     uint8_t provider = transponderConfig()->provider;
  93
  94     // TODO use a random number generator for random jitter?  The idea here is to avoid multiple transmitters transmitting at the same time.
  95     uint32_t jitter = (transponderRequirements[provider - 1].transmitJitter / 10 * jitterDurations[jitterIndex++]);
  96     if (jitterIndex >= JITTER_DURATION_COUNT) {
  97         jitterIndex = 0;
  98     }
  99
 100     nextUpdateAtUs = currentTimeUs + transponderRequirements[provider - 1].transmitDelay + jitter;
 101
 102 #ifdef REDUCE_TRANSPONDER_CURRENT_DRAW_WHEN_USB_CABLE_PRESENT
 103     // reduce current draw when USB cable is plugged in by decreasing the transponder transmit rate.
 104     if (usbCableIsInserted()) {
 105         nextUpdateAtUs = currentTimeUs + (1000 * 1000) / 10; // 10 hz.
 106     }
 107 #endif
 108
 109     transponderIrTransmit();
 110 }
 111
 112 void transponderInit(void)
 113 {
 114     transponderInitialised = transponderIrInit(transponderConfig()->ioTag, transponderConfig()->provider);
 115     if (!transponderInitialised) {
 116         return;
 117     }
 118
 119     transponderIrUpdateData(transponderConfig()->data);
 120 }
 121
 122 void transponderStopRepeating(void)
 123 {
 124     transponderRepeat = false;
 125 }
 126
 127 void transponderStartRepeating(void)
 128 {
 129     if (!transponderInitialised) {
 130         return;
 131     }
 132
 133     transponderRepeat = true;
 134 }
 135
 136 void transponderUpdateData(void)
 137 {
 138     if (!transponderInitialised) {
 139         return;
 140     }
 141
 142     transponderIrUpdateData(transponderConfig()->data);
 143 }
 144
 145 void transponderTransmitOnce(void)
 146 {
 147
 148     if (!transponderInitialised) {
 149         return;
 150     }
 151     transponderIrTransmit();
 152 }
 153 #endif