src/main/rx/sumh.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 /*
  22  * References:
  23  *  http://fpv-treff.de/viewtopic.php?f=18&t=1368&start=3020#p44535
  24  *  http://fpv-community.de/showthread.php?29033-MultiWii-mit-Graupner-SUMD-SUMH-und-USB-Joystick-auf-ProMicro
  25  */
  26
  27 #include <stdbool.h>
  28 #include <stdint.h>
  29 #include <stdlib.h>
  30
  31 #include "platform.h"
  32
  33 #ifdef USE_SERIALRX_SUMH
  34
  35 #include "common/utils.h"
  36
  37 #include "drivers/time.h"
  38
  39 #include "io/serial.h"
  40
  41 #ifdef USE_TELEMETRY
  42 #include "telemetry/telemetry.h"
  43 #endif
  44
  45 #include "pg/rx.h"
  46
  47 #include "rx/rx.h"
  48 #include "rx/sumh.h"
  49
  50 #define SUMH_BAUDRATE 115200
  51
  52 #define SUMH_MAX_CHANNEL_COUNT 8
  53 #define SUMH_FRAME_SIZE 21
  54
  55 static bool sumhFrameDone = false;
  56
  57 static uint8_t sumhFrame[SUMH_FRAME_SIZE];
  58 static uint32_t sumhChannels[SUMH_MAX_CHANNEL_COUNT];
  59
  60 static serialPort_t *sumhPort;
  61
  62 // Receive ISR callback
  63 static void sumhDataReceive(uint16_t c, void *data)
  64 {
  65     UNUSED(data);
  66
  67     uint32_t sumhTime;
  68     static uint32_t sumhTimeLast, sumhTimeInterval;
  69     static uint8_t sumhFramePosition;
  70
  71     sumhTime = micros();
  72     sumhTimeInterval = sumhTime - sumhTimeLast;
  73     sumhTimeLast = sumhTime;
  74     if (sumhTimeInterval > 5000) {
  75         sumhFramePosition = 0;
  76     }
  77
  78     sumhFrame[sumhFramePosition] = (uint8_t) c;
  79     if (sumhFramePosition == SUMH_FRAME_SIZE - 1) {
  80         // FIXME at this point the value of 'c' is unused and un tested, what should it be, is it important?
  81         sumhFrameDone = true;
  82     } else {
  83         sumhFramePosition++;
  84     }
  85 }
  86
  87 static uint8_t sumhFrameStatus(rxRuntimeState_t *rxRuntimeState)
  88 {
  89     UNUSED(rxRuntimeState);
  90
  91     uint8_t channelIndex;
  92
  93     if (!sumhFrameDone) {
  94         return RX_FRAME_PENDING;
  95     }
  96
  97     sumhFrameDone = false;
  98
  99     if (!((sumhFrame[0] == 0xA8) && (sumhFrame[SUMH_FRAME_SIZE - 2] == 0))) {
 100         return RX_FRAME_PENDING;
 101     }
 102
 103     for (channelIndex = 0; channelIndex < SUMH_MAX_CHANNEL_COUNT; channelIndex++) {
 104         sumhChannels[channelIndex] = (((uint32_t)(sumhFrame[(channelIndex << 1) + 3]) << 8)
 105                 + sumhFrame[(channelIndex << 1) + 4]) / 6.4f - 375;
 106     }
 107     return RX_FRAME_COMPLETE;
 108 }
 109
 110 static float sumhReadRawRC(const rxRuntimeState_t *rxRuntimeState, uint8_t chan)
 111 {
 112     UNUSED(rxRuntimeState);
 113
 114     if (chan >= SUMH_MAX_CHANNEL_COUNT) {
 115         return 0;
 116     }
 117
 118     return sumhChannels[chan];
 119 }
 120
 121 bool sumhInit(const rxConfig_t *rxConfig, rxRuntimeState_t *rxRuntimeState)
 122 {
 123     UNUSED(rxConfig);
 124
 125     rxRuntimeState->channelCount = SUMH_MAX_CHANNEL_COUNT;
 126     rxRuntimeState->rcReadRawFn = sumhReadRawRC;
 127     rxRuntimeState->rcFrameStatusFn = sumhFrameStatus;
 128
 129     const serialPortConfig_t *portConfig = findSerialPortConfig(FUNCTION_RX_SERIAL);
 130     if (!portConfig) {
 131         return false;
 132     }
 133
 134 #ifdef USE_TELEMETRY
 135     bool portShared = telemetryCheckRxPortShared(portConfig, rxRuntimeState->serialrxProvider);
 136 #else
 137     bool portShared = false;
 138 #endif
 139
 140     sumhPort = openSerialPort(portConfig->identifier, FUNCTION_RX_SERIAL, sumhDataReceive, NULL, SUMH_BAUDRATE, portShared ? MODE_RXTX : MODE_RX, (rxConfig->serialrx_inverted ? SERIAL_INVERTED : 0));
 141
 142 #ifdef USE_TELEMETRY
 143     if (portShared) {
 144         telemetrySharedPort = sumhPort;
 145     }
 146 #endif
 147
 148     return sumhPort != NULL;
 149 }
 150 #endif