added vtx_smartaudio_early_akk_workaround option

docs/Settings.md

@@ -501,6 +501,7 @@
 | vtx_max_power_override | 0 | Some VTXes may report max power incorrectly (i.e. 200mW for a 600mW VTX). Use this to override max supported power. 0 to disable and use whatever VTX reports as its capabilities |
 | vtx_pit_mode_chan |  |  |
 | vtx_power | 1 | VTX RF power level to use. The exact number of mw depends on the VTX hardware. |
+| vtx_smartaudio_early_akk_workaround | ON | Enable workaround for early AKK SAudio-enabled VTX bug. |
 | yaw_deadband | 5 | These are values (in us) by how much RC input can be different before it's considered valid. For transmitters with jitter on outputs, this value can be increased. Defaults are zero, but can be increased up to 10 or so if rc inputs twitch while idle. |
 | yaw_lpf_hz | 30 | Yaw low pass filter cutoff frequency. Should be disabled (set to `0`) on small multirotors (7 inches and below) |
 | yaw_rate | 20 | Defines rotation rate on YAW axis that UAV will try to archive on max. stick deflection. Rates are defined in tens of degrees (deca-degrees) per second [rate = dps/10]. That means, rate 20 represents 200dps rotation speed. Default 20 (200dps) is more less equivalent of old Cleanflight/Baseflight rate 0. Max. 180 (1800dps) is what gyro can measure. |

src/main/fc/settings.yaml

@@ -3112,6 +3112,11 @@ groups:
         default_value: "ON"
         field: halfDuplex
         type: bool
+      - name: vtx_smartaudio_early_akk_workaround
+        description: "Enable workaround for early AKK SAudio-enabled VTX bug."
+        default_value: "ON"
+        field: smartAudioEarlyAkkWorkaroundEnable
+        type: bool
 
   - name: PG_VTX_SETTINGS_CONFIG
     type: vtxSettingsConfig_t

src/main/io/vtx_control.c

@@ -39,10 +39,11 @@
 
 #if defined(USE_VTX_CONTROL)
 
-PG_REGISTER_WITH_RESET_TEMPLATE(vtxConfig_t, vtxConfig, PG_VTX_CONFIG, 2);
+PG_REGISTER_WITH_RESET_TEMPLATE(vtxConfig_t, vtxConfig, PG_VTX_CONFIG, 3);
 
 PG_RESET_TEMPLATE(vtxConfig_t, vtxConfig,
       .halfDuplex = true,
+      .smartAudioEarlyAkkWorkaroundEnable = true,
 );
 
 static uint8_t locked = 0;

src/main/io/vtx_control.h

@@ -31,6 +31,7 @@ typedef struct vtxChannelActivationCondition_s {
 typedef struct vtxConfig_s {
     vtxChannelActivationCondition_t vtxChannelActivationConditions[MAX_CHANNEL_ACTIVATION_CONDITION_COUNT];
     uint8_t halfDuplex;
+    uint8_t smartAudioEarlyAkkWorkaroundEnable;
 } vtxConfig_t;
 
 PG_DECLARE(vtxConfig_t, vtxConfig);

src/main/io/vtx_smartaudio.c

@@ -506,7 +506,8 @@ static void saSendFrame(uint8_t *buf, int len)
     // XXX: Workaround for early AKK SAudio-enabled VTX bug,
     // shouldn't cause any problems with VTX with properly
     // implemented SAudio.
-    serialWrite(smartAudioSerialPort, 0x00);
+	//Update: causes problem with new AKK AIO camera connected to SoftUART
+    if (vtxConfig()->smartAudioEarlyAkkWorkaroundEnable) serialWrite(smartAudioSerialPort, 0x00);
 
     sa_lastTransmissionMs = millis();
     saStat.pktsent++;