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