dshot: replace MOT_POLE_COUNT with per-motor parameters DSHOT_MOT_POL

src/drivers/dshot/DShot.cpp

@@ -618,7 +618,7 @@ bool DShot::process_bdshot_telemetry()
 
 				} else {
 					// Use previous value (esc_status is indexed by motor_index)
-					esc.erpm = _esc_status.esc[motor_index].esc_rpm * (_param_mot_pole_count.get() / 2);
+					esc.erpm = _esc_status.esc[motor_index].esc_rpm * (get_pole_count(motor_index) / 2);
 				}
 
 				// Extended DShot Telemetry
@@ -698,7 +698,7 @@ void DShot::consume_esc_data(const EscData &esc, TelemetrySource source)
 		// Only use SerialTelemetry eRPM when BDShot is disabled
 		if (!is_bdshot) {
 			_esc_status.esc[motor_index].timestamp = esc.timestamp;
-			_esc_status.esc[motor_index].esc_rpm = esc.erpm / (_param_mot_pole_count.get() / 2);
+			_esc_status.esc[motor_index].esc_rpm = esc.erpm / (get_pole_count(motor_index) / 2);
 		}
 
 		_esc_status.esc[motor_index].esc_voltage = esc.voltage;
@@ -707,7 +707,7 @@ void DShot::consume_esc_data(const EscData &esc, TelemetrySource source)
 
 	} else if (source == TelemetrySource::BDShot) {
 		_esc_status.esc[motor_index].timestamp = esc.timestamp;
-		_esc_status.esc[motor_index].esc_rpm = esc.erpm / (_param_mot_pole_count.get() / 2);
+		_esc_status.esc[motor_index].esc_rpm = esc.erpm / (get_pole_count(motor_index) / 2);
 
 		// Only use BDShot Volt/Curr/Temp when Serial Telemetry is disabled
 		if (!_serial_telemetry_enabled) {
@@ -874,6 +874,19 @@ void DShot::handle_esc_request_eeprom(const vehicle_command_s &command)
 	_command_ack_pub.publish(command_ack);
 }
 
+int DShot::get_pole_count(int motor_index)
+{
+	int32_t pole_count = 14;
+
+	int num_motors = (int)OutputFunction::MotorMax - ((int)OutputFunction::Motor1 - 1);
+
+	if (motor_index >= 0 && motor_index < num_motors) {
+		param_get(_param_pole_count_handles[motor_index], &pole_count);
+	}
+
+	return pole_count;
+}
+
 void DShot::update_params()
 {
 	parameter_update_s pupdate;
@@ -893,6 +906,13 @@ void DShot::update_params()
 			_mixing_output.minValue(i) = DSHOT_MIN_THROTTLE;
 		}
 	}
+
+	// Update per-motor pole count param handles
+	for (int i = 0; i < 12; i++) {
+		char name[20];
+		snprintf(name, sizeof(name), "DSHOT_MOT_POL%d", i + 1);
+		_param_pole_count_handles[i] = param_find(name);
+	}
 }
 
 void DShot::mixerChanged()
@@ -1052,9 +1072,17 @@ int DShot::print_status()
 	}
 
 	PX4_INFO("  ESC Type:           %s (%ld)", esc_type_str, _param_dshot_esc_type.get());
-	PX4_INFO("  Motor Poles:        %ld", _param_mot_pole_count.get());
 	PX4_INFO("  3D Mode:            %s", _param_dshot_3d_enable.get() ? "Enabled" : "Disabled");
 
+	// Per-motor pole counts
+	PX4_INFO("  Motor Poles:");
+
+	for (int i = 0; i < DSHOT_MAXIMUM_CHANNELS; i++) {
+		if (_motor_mask & (1 << i)) {
+			PX4_INFO("    Motor %d: %d poles", i + 1, get_pole_count(i));
+		}
+	}
+
 	// Telemetry Status
 	if (_bdshot_output_mask || _serial_telemetry_enabled) {
 		print_spacer();

src/drivers/dshot/DShot.h

@@ -223,6 +223,10 @@ private:
 	uint16_t _programming_address{};
 	uint16_t _programming_value{};
 
+	// Per-motor pole count
+	param_t _param_pole_count_handles[12] {};
+	int get_pole_count(int motor_index);
+
 	// Parameters
 	DEFINE_PARAMETERS(
 		(ParamInt<px4::params::DSHOT_ESC_TYPE>) _param_dshot_esc_type,
@@ -230,7 +234,6 @@ private:
 		(ParamBool<px4::params::DSHOT_3D_ENABLE>) _param_dshot_3d_enable,
 		(ParamInt<px4::params::DSHOT_3D_DEAD_H>) _param_dshot_3d_dead_h,
 		(ParamInt<px4::params::DSHOT_3D_DEAD_L>) _param_dshot_3d_dead_l,
-		(ParamInt<px4::params::MOT_POLE_COUNT>) _param_mot_pole_count,
 		(ParamBool<px4::params::DSHOT_BIDIR_EDT>) _param_dshot_bidir_edt
 	)
 };

src/drivers/dshot/module.yaml

@@ -72,14 +72,18 @@ parameters:
             min: 0
             max: 1000
             default: 1000
-        MOT_POLE_COUNT: # only used by dshot so far, so keep it under the dshot group
+        DSHOT_MOT_POL${i}:
             description:
-                short: Number of magnetic poles of the motors
+                short: Number of magnetic poles of motor ${i}
                 long: |
-                    Specify the number of magnetic poles of the motors.
+                    Number of magnetic poles for motor ${i}.
-                    It is required to compute the RPM value from the eRPM returned with the ESC telemetry.
+                    Required to compute RPM from the eRPM returned by ESC telemetry.
-
+                    Either get the number from the motor spec sheet or count the magnets
-                    Either get the number from the motor spec sheet or count the magnets on the bell of the motor (not the stator magnets).
+                    on the bell of the motor (not the stator magnets).
                     Typical motors for 5 inch props have 14 poles.
             type: int32
             default: 14
+            min: 2
+            max: 400
+            num_instances: 12
+            instance_start: 1