Implemented support for FlySky i-Bus serial receiver.

Makefile

@@ -298,6 +298,7 @@ COMMON_SRC = build_config.c \
 		   rx/sumh.c \
 		   rx/spektrum.c \
 		   rx/xbus.c \
+		   rx/ibus.c \
 		   sensors/acceleration.c \
 		   sensors/battery.c \
 		   sensors/boardalignment.c \

src/main/rx/ibus.c

@@ -0,0 +1,134 @@
+/*
+ * This file is part of Cleanflight.
+ *
+ * Cleanflight is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Cleanflight is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Cleanflight.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#include "platform.h"
+
+#include "build_config.h"
+
+#include "drivers/system.h"
+
+#include "drivers/serial.h"
+#include "drivers/serial_uart.h"
+#include "io/serial.h"
+
+#include "rx/rx.h"
+#include "rx/ibus.h"
+
+// Driver for IBUS (Flysky) receiver 
+
+#define IBUS_MAX_CHANNEL 8
+#define IBUS_BUFFSIZE 32
+#define IBUS_SYNCBYTE 0x20
+
+#define IBUS_BAUDRATE 115200
+
+static bool ibusFrameDone = false;
+static uint32_t ibusChannelData[IBUS_MAX_CHANNEL];
+
+static void ibusDataReceive(uint16_t c);
+static uint16_t ibusReadRawRC(rxRuntimeConfig_t *rxRuntimeConfig, uint8_t chan);
+
+bool ibusInit(rxConfig_t *rxConfig, rxRuntimeConfig_t *rxRuntimeConfig, rcReadRawDataPtr *callback)
+{
+    UNUSED(rxConfig);
+
+    if (callback)
+        *callback = ibusReadRawRC;
+
+    rxRuntimeConfig->channelCount = IBUS_MAX_CHANNEL;
+
+    serialPortConfig_t *portConfig = findSerialPortConfig(FUNCTION_RX_SERIAL);
+    if (!portConfig) {
+        return false;
+    }
+
+    serialPort_t *ibusPort = openSerialPort(portConfig->identifier, FUNCTION_RX_SERIAL, ibusDataReceive, IBUS_BAUDRATE, MODE_RX, SERIAL_NOT_INVERTED);
+
+    return ibusPort != NULL;
+}
+
+static uint8_t ibus[IBUS_BUFFSIZE] = { 0, };
+
+// Receive ISR callback
+static void ibusDataReceive(uint16_t c)
+{
+    uint32_t ibusTime;
+    static uint32_t ibusTimeLast;
+    static uint8_t ibusFramePosition;
+
+    ibusTime = micros();
+
+    if ((ibusTime - ibusTimeLast) > 3000)
+        ibusFramePosition = 0;
+
+    ibusTimeLast = ibusTime;
+
+    if (ibusFramePosition == 0 && c != IBUS_SYNCBYTE)
+        return;
+
+    ibus[ibusFramePosition] = (uint8_t)c;
+
+    if (ibusFramePosition == IBUS_BUFFSIZE - 1) {
+        ibusFrameDone = true;
+    } else {
+        ibusFramePosition++;
+    }
+}
+
+uint8_t ibusFrameStatus(void)
+{
+    uint8_t i;
+    uint8_t frameStatus = SERIAL_RX_FRAME_PENDING;
+    uint16_t chksum, rxsum;
+
+    if (!ibusFrameDone) {
+        return frameStatus;
+    }
+
+    ibusFrameDone = false;
+
+    chksum = 0xFFFF;
+    for (i = 0; i < 30; i++)
+        chksum -= ibus[i];
+        
+    rxsum = ibus[30] + (ibus[31] << 8);
+
+    if (chksum == rxsum) {
+        ibusChannelData[0] = (ibus[ 3] << 8) + ibus[ 2];
+        ibusChannelData[1] = (ibus[ 5] << 8) + ibus[ 4];
+        ibusChannelData[2] = (ibus[ 7] << 8) + ibus[ 6];
+        ibusChannelData[3] = (ibus[ 9] << 8) + ibus[ 8];
+        ibusChannelData[4] = (ibus[11] << 8) + ibus[10];
+        ibusChannelData[5] = (ibus[13] << 8) + ibus[12];
+        ibusChannelData[6] = (ibus[15] << 8) + ibus[14];
+        ibusChannelData[7] = (ibus[17] << 8) + ibus[16];
+        
+        frameStatus = SERIAL_RX_FRAME_COMPLETE;
+    }
+
+    return frameStatus;
+}
+
+static uint16_t ibusReadRawRC(rxRuntimeConfig_t *rxRuntimeConfig, uint8_t chan)
+{
+    UNUSED(rxRuntimeConfig);
+    return ibusChannelData[chan];
+}

src/main/rx/ibus.h

@@ -0,0 +1,20 @@
+/*
+ * This file is part of Cleanflight.
+ *
+ * Cleanflight is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Cleanflight is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Cleanflight.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+uint8_t ibusFrameStatus(void);

src/main/rx/rx.c

@@ -49,6 +49,7 @@
 #include "rx/sumh.h"
 #include "rx/msp.h"
 #include "rx/xbus.h"
+#include "rx/ibus.h"
 
 #include "rx/rx.h"
 
@@ -61,6 +62,7 @@ bool sbusInit(rxConfig_t *initialRxConfig, rxRuntimeConfig_t *rxRuntimeConfig, r
 bool spektrumInit(rxConfig_t *rxConfig, rxRuntimeConfig_t *rxRuntimeConfig, rcReadRawDataPtr *callback);
 bool sumdInit(rxConfig_t *rxConfig, rxRuntimeConfig_t *rxRuntimeConfig, rcReadRawDataPtr *callback);
 bool sumhInit(rxConfig_t *rxConfig, rxRuntimeConfig_t *rxRuntimeConfig, rcReadRawDataPtr *callback);
+bool ibusInit(rxConfig_t *rxConfig, rxRuntimeConfig_t *rxRuntimeConfig, rcReadRawDataPtr *callback);
 
 void rxMspInit(rxConfig_t *rxConfig, rxRuntimeConfig_t *rxRuntimeConfig, rcReadRawDataPtr *callback);
 
@@ -234,6 +236,9 @@ void serialRxInit(rxConfig_t *rxConfig)
             rxRefreshRate = 11000;
             enabled = xBusInit(rxConfig, &rxRuntimeConfig, &rcReadRawFunc);
             break;
+        case SERIALRX_IBUS:
+            enabled = ibusInit(rxConfig, &rxRuntimeConfig, &rcReadRawFunc);
+            break;
     }
 
     if (!enabled) {
@@ -266,6 +271,8 @@ uint8_t serialRxFrameStatus(rxConfig_t *rxConfig)
         case SERIALRX_XBUS_MODE_B:
         case SERIALRX_XBUS_MODE_B_RJ01:
             return xBusFrameStatus();
+        case SERIALRX_IBUS:
+            return ibusFrameStatus();
     }
     return SERIAL_RX_FRAME_PENDING;
 }

src/main/rx/rx.h

@@ -51,7 +51,8 @@ typedef enum {
     SERIALRX_SUMH = 4,
     SERIALRX_XBUS_MODE_B = 5,
     SERIALRX_XBUS_MODE_B_RJ01 = 6,
-    SERIALRX_PROVIDER_MAX = SERIALRX_XBUS_MODE_B_RJ01
+    SERIALRX_IBUS = 7,
+    SERIALRX_PROVIDER_MAX = SERIALRX_IBUS
 } SerialRXType;
 
 #define SERIALRX_PROVIDER_COUNT (SERIALRX_PROVIDER_MAX + 1)