2 * This file is part of Cleanflight.
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.
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.
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/>.
27 #include "build/debug.h"
29 #include "common/utils.h"
31 #include "drivers/time.h"
33 #include "io/serial.h"
36 #include "telemetry/telemetry.h"
41 #include "rx/sbus_channels.h"
47 * time between frames: 6ms.
48 * time to send frame: 3ms.
50 * Futaba R6208SB/R6303SB
51 * time between frames: 11ms.
52 * time to send frame: 3ms.
57 STATE_SBUS26_PAYLOAD_LOW
,
58 STATE_SBUS26_PAYLOAD_HIGH
,
62 typedef struct sbusFrameData_s
{
63 sbusDecoderState_e state
;
64 volatile sbusFrame_t frame
;
65 volatile bool frameDone
;
66 volatile bool is26channels
;
67 uint8_t buffer
[SBUS_FRAME_SIZE
];
69 timeUs_t lastActivityTimeUs
;
72 static uint8_t sbus2ActiveTelemetryPage
= 0;
73 static uint8_t sbus2ActiveTelemetrySlot
= 0;
74 timeUs_t frameTime
= 0;
76 // Receive ISR callback
77 static void sbusDataReceive(uint16_t c
, void *data
)
79 sbusFrameData_t
*sbusFrameData
= data
;
80 const timeUs_t currentTimeUs
= micros();
81 const timeDelta_t timeSinceLastByteUs
= cmpTimeUs(currentTimeUs
, sbusFrameData
->lastActivityTimeUs
);
82 sbusFrameData
->lastActivityTimeUs
= currentTimeUs
;
84 // Handle inter-frame gap. We dwell in STATE_SBUS_WAIT_SYNC state ignoring all incoming bytes until we get long enough quite period on the wire
85 if (sbusFrameData
->state
== STATE_SBUS_WAIT_SYNC
&& timeSinceLastByteUs
>= rxConfig()->sbusSyncInterval
) {
86 sbusFrameData
->state
= STATE_SBUS_SYNC
;
89 switch (sbusFrameData
->state
) {
91 // Ignore non 26 channel packets
92 if (c
== SBUS_FRAME_BEGIN_BYTE
&& !sbusFrameData
->is26channels
) {
93 sbusFrameData
->position
= 0;
94 sbusFrameData
->buffer
[sbusFrameData
->position
++] = (uint8_t)c
;
95 sbusFrameData
->state
= STATE_SBUS_PAYLOAD
;
96 } else if (c
== SBUS26_FRAME0_BEGIN_BYTE
) {
97 sbusFrameData
->position
= 0;
98 sbusFrameData
->buffer
[sbusFrameData
->position
++] = (uint8_t)c
;
99 sbusFrameData
->state
= STATE_SBUS26_PAYLOAD_LOW
;
100 } else if (c
== SBUS26_FRAME1_BEGIN_BYTE
) {
101 sbusFrameData
->position
= 0;
102 sbusFrameData
->buffer
[sbusFrameData
->position
++] = (uint8_t)c
;
103 sbusFrameData
->state
= STATE_SBUS26_PAYLOAD_HIGH
;
107 case STATE_SBUS_PAYLOAD
:
108 sbusFrameData
->buffer
[sbusFrameData
->position
++] = (uint8_t)c
;
110 if (sbusFrameData
->position
== SBUS_FRAME_SIZE
) {
111 const sbusFrame_t
* frame
= (sbusFrame_t
*)&sbusFrameData
->buffer
[0];
112 bool frameValid
= false;
114 // Do some sanity check
115 switch (frame
->endByte
) {
116 case 0x00: // This is S.BUS 1
117 case 0x04: // S.BUS 2 telemetry page 1
118 case 0x14: // S.BUS 2 telemetry page 2
119 case 0x24: // S.BUS 2 telemetry page 3
120 case 0x34: // S.BUS 2 telemetry page 4
121 if(frame
->endByte
& 0x4) {
122 sbus2ActiveTelemetryPage
= (frame
->endByte
>> 4) & 0xF;
123 frameTime
= currentTimeUs
;
125 sbus2ActiveTelemetryPage
= 0;
126 sbus2ActiveTelemetrySlot
= 0;
132 sbusFrameData
->state
= STATE_SBUS_WAIT_SYNC
;
135 default: // Failed end marker
136 sbusFrameData
->state
= STATE_SBUS_WAIT_SYNC
;
140 // Frame seems sane, pass data to decoder
141 if (!sbusFrameData
->frameDone
&& frameValid
) {
143 memcpy((void *)&sbusFrameData
->frame
, (void *)&sbusFrameData
->buffer
[0], SBUS_FRAME_SIZE
);
144 sbusFrameData
->frameDone
= true;
149 case STATE_SBUS26_PAYLOAD_LOW
:
150 case STATE_SBUS26_PAYLOAD_HIGH
:
151 sbusFrameData
->buffer
[sbusFrameData
->position
++] = (uint8_t)c
;
153 if (sbusFrameData
->position
== SBUS_FRAME_SIZE
) {
154 const sbusFrame_t
* frame
= (sbusFrame_t
*)&sbusFrameData
->buffer
[0];
155 bool frameValid
= false;
157 // Do some sanity check
158 switch (frame
->endByte
) {
159 case 0x20: // S.BUS 2 telemetry page 1
160 case 0x24: // S.BUS 2 telemetry page 2
161 case 0x28: // S.BUS 2 telemetry page 3
162 case 0x2C: // S.BUS 2 telemetry page 4
163 if (frame
->syncByte
== SBUS26_FRAME1_BEGIN_BYTE
) {
164 sbus2ActiveTelemetryPage
= (frame
->endByte
>> 2) & 0x3;
165 frameTime
= currentTimeUs
;
169 sbusFrameData
->state
= STATE_SBUS_WAIT_SYNC
;
172 default: // Failed end marker
173 sbusFrameData
->state
= STATE_SBUS_WAIT_SYNC
;
177 // Frame seems sane, pass data to decoder
178 if (!sbusFrameData
->frameDone
&& frameValid
) {
179 memcpy((void *)&sbusFrameData
->frame
, (void *)&sbusFrameData
->buffer
[0], SBUS_FRAME_SIZE
);
180 sbusFrameData
->frameDone
= true;
181 sbusFrameData
->is26channels
= true;
188 case STATE_SBUS_WAIT_SYNC
:
189 // Stay at this state and do nothing. Exit will be handled before byte is processed if the
190 // inter-frame gap is long enough
195 static uint8_t sbusFrameStatus(rxRuntimeConfig_t
*rxRuntimeConfig
)
197 sbusFrameData_t
*sbusFrameData
= rxRuntimeConfig
->frameData
;
199 if (!sbusFrameData
->frameDone
) {
200 return RX_FRAME_PENDING
;
203 // Decode channel data and store return value
204 const uint8_t retValue
= sbusFrameData
->is26channels
?
205 sbus26ChannelsDecode(rxRuntimeConfig
, (void *)&sbusFrameData
->frame
.channels
, (sbusFrameData
->frame
.syncByte
== SBUS26_FRAME1_BEGIN_BYTE
)) :
206 sbusChannelsDecode(rxRuntimeConfig
, (void *)&sbusFrameData
->frame
.channels
);
208 // Reset the frameDone flag - tell ISR that we're ready to receive next frame
209 sbusFrameData
->frameDone
= false;
211 //taskSendSbus2Telemetry(micros());
213 // Calculate "virtual link quality based on packet loss metric"
214 if (retValue
& RX_FRAME_COMPLETE
) {
215 lqTrackerAccumulate(rxRuntimeConfig
->lqTracker
, ((retValue
& RX_FRAME_DROPPED
) || (retValue
& RX_FRAME_FAILSAFE
)) ? 0 : RSSI_MAX_VALUE
);
221 static bool sbusInitEx(const rxConfig_t
*rxConfig
, rxRuntimeConfig_t
*rxRuntimeConfig
, uint32_t sbusBaudRate
)
223 static uint16_t sbusChannelData
[SBUS_MAX_CHANNEL
];
224 static sbusFrameData_t sbusFrameData
= { .is26channels
= false};
226 rxRuntimeConfig
->channelData
= sbusChannelData
;
227 rxRuntimeConfig
->frameData
= &sbusFrameData
;
229 sbusChannelsInit(rxRuntimeConfig
);
231 rxRuntimeConfig
->channelCount
= SBUS_MAX_CHANNEL
;
233 rxRuntimeConfig
->rcFrameStatusFn
= sbusFrameStatus
;
235 const serialPortConfig_t
*portConfig
= findSerialPortConfig(FUNCTION_RX_SERIAL
);
241 bool portShared
= telemetryCheckRxPortShared(portConfig
);
243 bool portShared
= false;
246 serialPort_t
*sBusPort
= openSerialPort(portConfig
->identifier
,
251 (portShared
|| rxConfig
->serialrx_provider
== SERIALRX_SBUS2
) ? MODE_RXTX
: MODE_RX
,
253 (rxConfig
->serialrx_inverted
? 0 : SERIAL_INVERTED
) |
254 ((rxConfig
->serialrx_provider
== SERIALRX_SBUS2
) ? SERIAL_BIDIR
: 0) |
255 (tristateWithDefaultOffIsActive(rxConfig
->halfDuplex
) ? SERIAL_BIDIR
: 0)
259 if (portShared
|| (rxConfig
->serialrx_provider
== SERIALRX_SBUS2
)) {
260 telemetrySharedPort
= sBusPort
;
264 return sBusPort
!= NULL
;
267 bool sbusInit(const rxConfig_t
*rxConfig
, rxRuntimeConfig_t
*rxRuntimeConfig
)
269 return sbusInitEx(rxConfig
, rxRuntimeConfig
, SBUS_BAUDRATE
);
272 bool sbusInitFast(const rxConfig_t
*rxConfig
, rxRuntimeConfig_t
*rxRuntimeConfig
)
274 return sbusInitEx(rxConfig
, rxRuntimeConfig
, SBUS_BAUDRATE_FAST
);
277 #if defined(USE_TELEMETRY) && defined(USE_TELEMETRY_SBUS2)
278 timeUs_t
sbusGetLastFrameTime(void) {
282 uint8_t sbusGetCurrentTelemetryNextSlot(void)
284 uint8_t current
= sbus2ActiveTelemetrySlot
;
285 sbus2ActiveTelemetrySlot
++;
289 uint8_t sbusGetCurrentTelemetryPage(void) {
290 return sbus2ActiveTelemetryPage
;
292 #endif // USE_TELEMETRY && USE_SBUS2_TELEMETRY
294 #endif // USE_SERIAL_RX