src/main/rx/sumh.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 /*
  19  * References:
  20  *  http://fpv-treff.de/viewtopic.php?f=18&t=1368&start=3020#p44535
  21  *  http://fpv-community.de/showthread.php?29033-MultiWii-mit-Graupner-SUMD-SUMH-und-USB-Joystick-auf-ProMicro
  22  */
  23
  24 #include <stdbool.h>
  25 #include <stdint.h>
  26 #include <stdlib.h>
  27
  28 #include "platform.h"
  29
  30 #ifdef USE_SERIAL_RX
  31
  32 #include "common/utils.h"
  33
  34 #include "drivers/time.h"
  35
  36 #include "io/serial.h"
  37
  38 #ifdef USE_TELEMETRY
  39 #include "telemetry/telemetry.h"
  40 #endif
  41
  42 #include "rx/rx.h"
  43 #include "rx/sumh.h"
  44
  45 // driver for SUMH receiver using UART2
  46
  47 #define SUMH_BAUDRATE 115200
  48
  49 #define SUMH_MAX_CHANNEL_COUNT 8
  50 #define SUMH_FRAME_SIZE 21
  51
  52 static bool sumhFrameDone = false;
  53
  54 static uint8_t sumhFrame[SUMH_FRAME_SIZE];
  55 static uint32_t sumhChannels[SUMH_MAX_CHANNEL_COUNT];
  56
  57 static serialPort_t *sumhPort;
  58
  59
  60 // Receive ISR callback
  61 static void sumhDataReceive(uint16_t c, void *data)
  62 {
  63     UNUSED(data);
  64
  65     uint32_t sumhTime;
  66     static uint32_t sumhTimeLast, sumhTimeInterval;
  67     static uint8_t sumhFramePosition;
  68
  69     sumhTime = micros();
  70     sumhTimeInterval = sumhTime - sumhTimeLast;
  71     sumhTimeLast = sumhTime;
  72     if (sumhTimeInterval > 5000) {
  73         sumhFramePosition = 0;
  74     }
  75
  76     sumhFrame[sumhFramePosition] = (uint8_t) c;
  77     if (sumhFramePosition == SUMH_FRAME_SIZE - 1) {
  78         // FIXME at this point the value of 'c' is unused and un tested, what should it be, is it important?
  79         sumhFrameDone = true;
  80     } else {
  81         sumhFramePosition++;
  82     }
  83 }
  84
  85 static uint8_t sumhFrameStatus(rxRuntimeConfig_t *rxRuntimeConfig)
  86 {
  87     UNUSED(rxRuntimeConfig);
  88
  89     uint8_t channelIndex;
  90
  91     if (!sumhFrameDone) {
  92         return RX_FRAME_PENDING;
  93     }
  94
  95     sumhFrameDone = false;
  96
  97     if (!((sumhFrame[0] == 0xA8) && (sumhFrame[SUMH_FRAME_SIZE - 2] == 0))) {
  98         return RX_FRAME_PENDING;
  99     }
 100
 101     for (channelIndex = 0; channelIndex < SUMH_MAX_CHANNEL_COUNT; channelIndex++) {
 102         sumhChannels[channelIndex] = (((uint32_t)(sumhFrame[(channelIndex << 1) + 3]) << 8)
 103                 + sumhFrame[(channelIndex << 1) + 4]) / 6.4f - 375;
 104     }
 105     return RX_FRAME_COMPLETE;
 106 }
 107
 108 static uint16_t sumhReadRawRC(const rxRuntimeConfig_t *rxRuntimeConfig, uint8_t chan)
 109 {
 110     UNUSED(rxRuntimeConfig);
 111
 112     if (chan >= SUMH_MAX_CHANNEL_COUNT) {
 113         return 0;
 114     }
 115
 116     return sumhChannels[chan];
 117 }
 118
 119 bool sumhInit(const rxConfig_t *rxConfig, rxRuntimeConfig_t *rxRuntimeConfig)
 120 {
 121     UNUSED(rxConfig);
 122
 123     rxRuntimeConfig->channelCount = SUMH_MAX_CHANNEL_COUNT;
 124     rxRuntimeConfig->rxRefreshRate = 11000;
 125
 126     rxRuntimeConfig->rcReadRawFn = sumhReadRawRC;
 127     rxRuntimeConfig->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);
 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