src/main/io/transponder_ir.c

   1 /*
   2  * This file is part of Cleanflight.
   3  *
   4  * Cleanflight 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 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * Cleanflight is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with Cleanflight.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include <stdbool.h>
  19 #include <stdlib.h>
  20 #include <stdint.h>
  21 #include <string.h>
  22 #include <stdarg.h>
  23
  24 #include <platform.h>
  25
  26 #ifdef TRANSPONDER
  27 #include "build/build_config.h"
  28
  29 #include "config/config_reset.h"
  30 #include "config/parameter_group.h"
  31 #include "config/parameter_group_ids.h"
  32
  33 #include "drivers/timer.h"
  34 #include "drivers/transponder_ir.h"
  35 #include "drivers/system.h"
  36 #include "drivers/usb_io.h"
  37
  38 #include "fc/config.h"
  39
  40 #include "io/transponder_ir.h"
  41
  42 PG_REGISTER_WITH_RESET_FN(transponderConfig_t, transponderConfig, PG_TRANSPONDER_CONFIG, 0);
  43
  44 void pgResetFn_transponderConfig(transponderConfig_t *transponderConfig)
  45 {
  46     RESET_CONFIG_2(transponderConfig_t, transponderConfig,
  47         .provider = TRANSPONDER_ILAP,
  48         .reserved = 0,
  49         .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
  50         .ioTag = IO_TAG_NONE
  51     );
  52
  53     for (int i = 0; i < USABLE_TIMER_CHANNEL_COUNT; i++) {
  54         if (timerHardware[i].usageFlags & TIM_USE_TRANSPONDER) {
  55             transponderConfig->ioTag = timerHardware[i].tag;
  56             break;
  57         }
  58     }
  59 }
  60
  61 static bool transponderInitialised = false;
  62 static bool transponderRepeat = false;
  63
  64 // timers
  65 static timeUs_t nextUpdateAtUs = 0;
  66
  67 #define JITTER_DURATION_COUNT (sizeof(jitterDurations) / sizeof(uint8_t))
  68 static uint8_t jitterDurations[] = {0,9,4,8,3,9,6,7,1,6,9,7,8,2,6};
  69
  70 const transponderRequirement_t transponderRequirements[TRANSPONDER_PROVIDER_COUNT] = {
  71     {TRANSPONDER_ILAP, TRANSPONDER_DATA_LENGTH_ILAP, TRANSPONDER_TRANSMIT_DELAY_ILAP, TRANSPONDER_TRANSMIT_JITTER_ILAP},
  72     {TRANSPONDER_ARCITIMER, TRANSPONDER_DATA_LENGTH_ARCITIMER, TRANSPONDER_TRANSMIT_DELAY_ARCITIMER, TRANSPONDER_TRANSMIT_JITTER_ARCITIMER},
  73     {TRANSPONDER_ERLT, TRANSPONDER_DATA_LENGTH_ERLT, TRANSPONDER_TRANSMIT_DELAY_ERLT, TRANSPONDER_TRANSMIT_JITTER_ERLT}
  74 };
  75
  76 void transponderUpdate(timeUs_t currentTimeUs)
  77 {
  78     static uint32_t jitterIndex = 0;
  79
  80     if (!(transponderInitialised && transponderRepeat && isTransponderIrReady())) {
  81         return;
  82     }
  83
  84     const bool updateNow = (timeDelta_t)(currentTimeUs - nextUpdateAtUs) >= 0L;
  85     if (!updateNow) {
  86         return;
  87     }
  88
  89     uint8_t provider = transponderConfig()->provider;
  90
  91     // TODO use a random number generator for random jitter?  The idea here is to avoid multiple transmitters transmitting at the same time.
  92     uint32_t jitter = (transponderRequirements[provider - 1].transmitJitter / 10 * jitterDurations[jitterIndex++]);
  93     if (jitterIndex >= JITTER_DURATION_COUNT) {
  94         jitterIndex = 0;
  95     }
  96
  97     nextUpdateAtUs = currentTimeUs + transponderRequirements[provider - 1].transmitDelay + jitter;
  98
  99 #ifdef REDUCE_TRANSPONDER_CURRENT_DRAW_WHEN_USB_CABLE_PRESENT
 100     // reduce current draw when USB cable is plugged in by decreasing the transponder transmit rate.
 101     if (usbCableIsInserted()) {
 102         nextUpdateAtUs = currentTimeUs + (1000 * 1000) / 10; // 10 hz.
 103     }
 104 #endif
 105
 106     transponderIrTransmit();
 107 }
 108
 109 void transponderInit(void)
 110 {
 111     transponderInitialised = transponderIrInit(transponderConfig()->ioTag, transponderConfig()->provider);
 112     if (!transponderInitialised) {
 113         return;
 114     }
 115
 116     transponderIrUpdateData(transponderConfig()->data);
 117 }
 118
 119 void transponderStopRepeating(void)
 120 {
 121     transponderRepeat = false;
 122 }
 123
 124 void transponderStartRepeating(void)
 125 {
 126     if (!transponderInitialised) {
 127         return;
 128     }
 129
 130     transponderRepeat = true;
 131 }
 132
 133 void transponderUpdateData(void)
 134 {
 135     if (!transponderInitialised) {
 136         return;
 137     }
 138
 139     transponderIrUpdateData(transponderConfig()->data);
 140 }
 141
 142 void transponderTransmitOnce(void) {
 143
 144     if (!transponderInitialised) {
 145         return;
 146     }
 147     transponderIrTransmit();
 148 }
 149 #endif