AP_HAL: add dshot command codes for beeps, leds and motor control

allow more than one type of ESC for dshot commands
add support for checks around active ESCs
allow dshot alarm to be disabled
allow prioritized dshot commands

libraries/AP_HAL/RCOutput.h

@@ -57,6 +57,12 @@ public:
      */
     virtual void     set_reversible_mask(uint16_t chanmask) {}
     
+    /*
+     * mark the channels in chanmask as reversed. The chanmask passed is added (ORed) into
+     * any existing mask.
+     */
+    virtual void     set_reversed_mask(uint16_t chanmask) {}
+
     /*
      * Delay subsequent calls to write() going to the underlying hardware in
      * order to group related writes together. When all the needed writes are
@@ -187,6 +193,38 @@ public:
         MODE_NEOPIXEL,  // same as MODE_PWM_DSHOT at 800kHz but it's an LED
         MODE_PROFILED,  // same as MODE_PWM_DSHOT using separate clock and data
     };
+
+    // https://github.com/bitdump/BLHeli/blob/master/BLHeli_32%20ARM/BLHeli_32%20Firmware%20specs/Digital_Cmd_Spec.txt
+    enum BLHeliDshotCommand : uint8_t {
+      DSHOT_RESET = 0,
+      DSHOT_BEEP1 = 1,
+      DSHOT_BEEP2 = 2,
+      DSHOT_BEEP3 = 3,
+      DSHOT_BEEP4 = 4,
+      DSHOT_BEEP5 = 5,
+      DSHOT_ESC_INFO = 6,
+      DSHOT_ROTATE = 7,
+      DSHOT_ROTATE_ALTERNATE = 8,
+      DSHOT_3D_OFF = 9,
+      DSHOT_3D_ON = 10,
+      DSHOT_SAVE = 12,
+      DSHOT_NORMAL = 20,
+      DSHOT_REVERSE = 21,
+      DSHOT_LED0_ON = 22,
+      DSHOT_LED1_ON = 23,
+      DSHOT_LED2_ON = 24,
+      DSHOT_LED3_ON = 25,
+      DSHOT_LED0_OFF = 26,
+      DSHOT_LED1_OFF = 27,
+      DSHOT_LED2_OFF = 28,
+      DSHOT_LED3_OFF = 29,
+    };
+
+    enum DshotEscType {
+      DSHOT_ESC_NONE = 0,
+      DSHOT_ESC_BLHELI = 1
+    };
+
     virtual void    set_output_mode(uint16_t mask, enum output_mode mode) {}
 
     /*
@@ -211,11 +249,35 @@ public:
      */
     virtual void set_bidir_dshot_mask(uint16_t mask) {}
 
+    /*
+      mark escs as active for the purpose of sending dshot commands
+     */
+    virtual void set_active_escs_mask(uint16_t mask) {}
+
     /*
       Set the dshot rate as a multiple of the loop rate
      */
     virtual void set_dshot_rate(uint8_t dshot_rate, uint16_t loop_rate_hz) {}
 
+    /*
+      Set the dshot ESC type
+     */
+    virtual void set_dshot_esc_type(DshotEscType esc_type) {}
+
+    virtual DshotEscType get_dshot_esc_type() const { return DSHOT_ESC_NONE; }
+
+    const static uint32_t ALL_CHANNELS = 255;
+    /*
+      Send a dshot command, if command timout is 0 then 10 commands are sent
+      chan is the servo channel to send the command to
+     */
+    virtual void send_dshot_command(uint8_t command, uint8_t chan = ALL_CHANNELS, uint32_t command_timeout_ms = 0, uint16_t repeat_count = 10, bool priority = false) {}
+
+    /*
+      If not already done flush any dshot commands still pending
+     */
+    virtual bool prepare_for_arming() { return true; }
+
     /*
       setup serial led output for a given channel number, with
       the given max number of LEDs in the chain.

libraries/AP_HAL/Util.h

@@ -128,7 +128,13 @@ public:
     /*
         ToneAlarm Driver
     */
-    virtual bool toneAlarm_init() { return false;}
+    enum ToneAlarmType {
+        ALARM_NONE=0,
+        ALARM_BUZZER=1<<0,
+        ALARM_DSHOT=1<<1
+    };
+
+    virtual bool toneAlarm_init(uint8_t types) { return false;}
     virtual void toneAlarm_set_buzzer_tone(float frequency, float volume, uint32_t duration_ms) {}
 
     /*

libraries/AP_HAL/board/chibios.h

@@ -108,6 +108,14 @@
 #define HAL_SUPPORT_RCOUT_SERIAL !defined(HAL_BUILD_AP_PERIPH)
 #endif
 
+#ifndef HAL_DSHOT_ALARM
+#if !defined(HAL_BUILD_AP_PERIPH) && !defined(HAL_BOOTLOADER_BUILD)
+#define HAL_DSHOT_ALARM 1
+#else
+#define HAL_DSHOT_ALARM 0
+#endif
+#endif
+
 // by default assume first I2C bus is internal
 #ifndef HAL_I2C_INTERNAL_MASK
 #define HAL_I2C_INTERNAL_MASK 1

libraries/AP_HAL/board/linux.h

@@ -7,6 +7,7 @@
 #define HAL_OS_SOCKETS 1
 #define HAL_STORAGE_SIZE            16384
 #define HAL_STORAGE_SIZE_AVAILABLE  HAL_STORAGE_SIZE
+#define HAL_DSHOT_ALARM 0
 
 // make sensor selection clearer
 #define PROBE_IMU_I2C(driver, bus, addr, args ...) ADD_BACKEND(AP_InertialSensor_ ## driver::probe(*this,GET_I2C_DEVICE(bus, addr),##args))

libraries/AP_HAL/board/sitl.h

@@ -5,6 +5,7 @@
 #define HAL_MEM_CLASS HAL_MEM_CLASS_1000
 #define HAL_OS_POSIX_IO 1
 #define HAL_OS_SOCKETS 1
+#define HAL_DSHOT_ALARM 0
 
 #define AP_FLASHSTORAGE_TYPE 3