AP_RPM: added a new RPM driver based on ESC telem

this adds a new RPM driver based on average RPM of selected motors.
A new bitmask parameter has been added to select which motor to average.

libraries/AP_RPM/AP_RPM.cpp

@@ -18,6 +18,7 @@
 #include "RPM_SITL.h"
 #include "RPM_EFI.h"
 #include "RPM_HarmonicNotch.h"
+#include "RPM_ESC_Telem.h"
 
 extern const AP_HAL::HAL& hal;
 
@@ -26,7 +27,7 @@ const AP_Param::GroupInfo AP_RPM::var_info[] = {
     // @Param: _TYPE
     // @DisplayName: RPM type
     // @Description: What type of RPM sensor is connected
-    // @Values: 0:None,1:PWM,2:AUXPIN,3:EFI,4:Harmonic Notch
+    // @Values: 0:None,1:PWM,2:AUXPIN,3:EFI,4:Harmonic Notch,5:ESC Telemetry Motors Bitmask
     // @User: Standard
     AP_GROUPINFO("_TYPE",    0, AP_RPM, _type[0], 0),
 
@@ -64,12 +65,19 @@ const AP_Param::GroupInfo AP_RPM::var_info[] = {
     // @Values: -1:Disabled,50:PixhawkAUX1,51:PixhawkAUX2,52:PixhawkAUX3,53:PixhawkAUX4,54:PixhawkAUX5,55:PixhawkAUX6
     // @User: Standard
     AP_GROUPINFO("_PIN",    5, AP_RPM, _pin[0], 54),
-    
+
+    // @Param: _ESC_MASK
+    // @DisplayName: Bitmask of ESC telemetry channels to average
+    // @Description: Mask of channels which support ESC rpm telemetry. RPM telemetry of the selected channels will be averaged
+    // @Bitmask: 0:Channel1,1:Channel2,2:Channel3,3:Channel4,4:Channel5,5:Channel6,6:Channel7,7:Channel8,8:Channel9,9:Channel10,10:Channel11,11:Channel12,12:Channel13,13:Channel14,14:Channel15,15:Channel16
+    // @User: Advanced
+    AP_GROUPINFO("_ESC_MASK",  6, AP_RPM, _esc_mask[0], 0),
+
 #if RPM_MAX_INSTANCES > 1
     // @Param: 2_TYPE
     // @DisplayName: Second RPM type
     // @Description: What type of RPM sensor is connected
-    // @Values: 0:None,1:PWM,2:AUXPIN,3:EFI,4:Harmonic Notch
+    // @Values: 0:None,1:PWM,2:AUXPIN,3:EFI,4:Harmonic Notch,5:ESC Telemetry Motors Bitmask
     // @User: Advanced
     AP_GROUPINFO("2_TYPE",    10, AP_RPM, _type[1], 0),
 
@@ -86,6 +94,13 @@ const AP_Param::GroupInfo AP_RPM::var_info[] = {
     // @Values: -1:Disabled,50:PixhawkAUX1,51:PixhawkAUX2,52:PixhawkAUX3,53:PixhawkAUX4,54:PixhawkAUX5,55:PixhawkAUX6
     // @User: Standard
     AP_GROUPINFO("2_PIN",    12, AP_RPM, _pin[1], -1),
+
+    // @Param: 2_ESC_MASK
+    // @DisplayName: Bitmask of ESC telemetry channels to average
+    // @Description: Mask of channels which support ESC rpm telemetry. RPM telemetry of the selected channels will be averaged
+    // @Bitmask: 0:Channel1,1:Channel2,2:Channel3,3:Channel4,4:Channel5,5:Channel6,6:Channel7,7:Channel8,8:Channel9,9:Channel10,10:Channel11,11:Channel12,12:Channel13,13:Channel14,14:Channel15,15:Channel16
+    // @User: Advanced
+    AP_GROUPINFO("2_ESC_MASK",  13, AP_RPM, _esc_mask[1], 0),
 #endif
 
     AP_GROUPEND
@@ -102,7 +117,7 @@ AP_RPM::AP_RPM(void)
 }
 
 /*
-  initialise the AP_RPM class. 
+  initialise the AP_RPM class.
  */
 void AP_RPM::init(void)
 {
@@ -111,31 +126,33 @@ void AP_RPM::init(void)
         return;
     }
     for (uint8_t i=0; i<RPM_MAX_INSTANCES; i++) {
-        uint8_t type = _type[i];
+        switch (_type[i]) {
 #if CONFIG_HAL_BOARD != HAL_BOARD_SITL
-        if (type == RPM_TYPE_PWM) {
+        case RPM_TYPE_PWM:
+        case RPM_TYPE_PIN:
             // PWM option same as PIN option, for upgrade
-            type = RPM_TYPE_PIN;
-        }
-        if (type == RPM_TYPE_PIN) {
             drivers[i] = new AP_RPM_Pin(*this, i, state[i]);
-        }
+            break;
 #endif
+        case RPM_TYPE_ESC_TELEM:
+            drivers[i] = new AP_RPM_ESC_Telem(*this, i, state[i]);
+            break;
 #if HAL_EFI_ENABLED
-        if (type == RPM_TYPE_EFI) {
+        case RPM_TYPE_EFI:
             drivers[i] = new AP_RPM_EFI(*this, i, state[i]);
-        }
+            break;
 #endif
         // include harmonic notch last
         // this makes whatever process is driving the dynamic notch appear as an RPM value
-        if (type == RPM_TYPE_HNTCH) {
+        case RPM_TYPE_HNTCH:
             drivers[i] = new AP_RPM_HarmonicNotch(*this, i, state[i]);
-        }
+            break;
 #if CONFIG_HAL_BOARD == HAL_BOARD_SITL
-        if (type == RPM_TYPE_SITL) {
+        case RPM_TYPE_SITL:
             drivers[i] = new AP_RPM_SITL(*this, i, state[i]);
-        }
+            break;
 #endif
+        }
         if (drivers[i] != nullptr) {
             // we loaded a driver for this instance, so it must be
             // present (although it may not be healthy)
@@ -161,7 +178,7 @@ void AP_RPM::update(void)
         }
     }
 }
-    
+
 /*
   check if an instance is healthy
  */

libraries/AP_RPM/AP_RPM.h

@@ -42,6 +42,7 @@ public:
         RPM_TYPE_PIN     = 2,
         RPM_TYPE_EFI     = 3,
         RPM_TYPE_HNTCH   = 4,
+        RPM_TYPE_ESC_TELEM  = 5,
 #if CONFIG_HAL_BOARD == HAL_BOARD_SITL
         RPM_TYPE_SITL   = 10,
 #endif
@@ -62,6 +63,7 @@ public:
     AP_Float _maximum[RPM_MAX_INSTANCES];
     AP_Float _minimum[RPM_MAX_INSTANCES];
     AP_Float _quality_min[RPM_MAX_INSTANCES];
+    AP_Int32 _esc_mask[RPM_MAX_INSTANCES];
 
     static const struct AP_Param::GroupInfo var_info[];
 

libraries/AP_RPM/RPM_ESC_Telem.cpp

@@ -0,0 +1,42 @@
+/*
+   This program 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.
+
+   This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <AP_HAL/AP_HAL.h>
+#include <AP_ESC_Telem/AP_ESC_Telem.h>
+
+#include "RPM_ESC_Telem.h"
+
+extern const AP_HAL::HAL& hal;
+
+/*
+   open the sensor in constructor
+*/
+AP_RPM_ESC_Telem::AP_RPM_ESC_Telem(AP_RPM &_ap_rpm, uint8_t _instance, AP_RPM::RPM_State &_state) :
+    AP_RPM_Backend(_ap_rpm, _instance, _state)
+{
+    instance = _instance;
+}
+
+
+void AP_RPM_ESC_Telem::update(void)
+{
+#ifdef HAL_WITH_ESC_TELEM
+    AP_ESC_Telem &esc_telem = AP::esc_telem();
+    float esc_rpm = esc_telem.get_average_motor_rpm(ap_rpm._esc_mask[state.instance]);
+    state.rate_rpm = esc_rpm * ap_rpm._scaling[state.instance];
+    state.signal_quality = 0.5f;
+    state.last_reading_ms = AP_HAL::millis();
+#endif
+}

libraries/AP_RPM/RPM_ESC_Telem.h

@@ -0,0 +1,30 @@
+/*
+   This program 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.
+
+   This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#pragma once
+
+#include "AP_RPM.h"
+#include "RPM_Backend.h"
+
+class AP_RPM_ESC_Telem : public AP_RPM_Backend
+{
+public:
+    // constructor
+    AP_RPM_ESC_Telem(AP_RPM &ranger, uint8_t instance, AP_RPM::RPM_State &_state);
+
+    // update state
+    void update(void) override;
+private:
+    uint8_t instance;
+};