diff --git a/libraries/AP_OpticalFlow/AP_OpticalFlow_MAV.cpp b/libraries/AP_OpticalFlow/AP_OpticalFlow_MAV.cpp
new file mode 100644
index 00000000000..c15195b0183
--- /dev/null
+++ b/libraries/AP_OpticalFlow/AP_OpticalFlow_MAV.cpp
@@ -0,0 +1,107 @@
+/*
+ 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 .
+ */
+
+#include
+#include
+#include "AP_OpticalFlow_MAV.h"
+
+#define OPTFLOW_MAV_TIMEOUT_SEC 0.5f
+
+// detect the device
+AP_OpticalFlow_MAV *AP_OpticalFlow_MAV::detect(OpticalFlow &_frontend)
+{
+ // we assume mavlink messages will be sent into this driver
+ AP_OpticalFlow_MAV *sensor = new AP_OpticalFlow_MAV(_frontend);
+ return sensor;
+}
+
+// read latest values from sensor and fill in x,y and totals.
+void AP_OpticalFlow_MAV::update(void)
+{
+ // record gyro values as long as they are being used
+ // the sanity check of dt below ensures old gyro values are not used
+ if (gyro_sum_count < 1000) {
+ const Vector3f& gyro = AP::ahrs().get_gyro();
+ gyro_sum.x += gyro.x;
+ gyro_sum.y += gyro.y;
+ gyro_sum_count++;
+ }
+
+ // return without updating state if no readings
+ if (count == 0) {
+ return;
+ }
+
+ struct OpticalFlow::OpticalFlow_state state {};
+
+ state.device_id = sensor_id;
+ state.surface_quality = quality_sum / count;
+
+ // calculate dt
+ const float dt = (latest_frame_us - prev_frame_us) * 1.0e-6;
+ prev_frame_us = latest_frame_us;
+
+ // sanity check dt
+ if (is_positive(dt) && (dt < OPTFLOW_MAV_TIMEOUT_SEC)) {
+ // calculate flow values
+ const float flow_scale_factor_x = 1.0f + 0.001f * _flowScaler().x;
+ const float flow_scale_factor_y = 1.0f + 0.001f * _flowScaler().y;
+
+ // copy flow rates to state structure
+ state.flowRate = { ((float)flow_sum.x / count) * flow_scale_factor_x * dt,
+ ((float)flow_sum.y / count) * flow_scale_factor_y * dt };
+
+ // copy average body rate to state structure
+ state.bodyRate = { gyro_sum.x / gyro_sum_count, gyro_sum.y / gyro_sum_count };
+
+ _applyYaw(state.flowRate);
+ _applyYaw(state.bodyRate);
+ } else {
+ // first frame received in some time so cannot calculate flow values
+ state.flowRate.zero();
+ state.bodyRate.zero();
+ }
+
+ _update_frontend(state);
+
+ // reset local buffers
+ flow_sum.zero();
+ quality_sum = 0;
+ count = 0;
+
+ // reset gyro sum
+ gyro_sum.zero();
+ gyro_sum_count = 0;
+}
+
+// handle OPTICAL_FLOW mavlink messages
+void AP_OpticalFlow_MAV::handle_msg(const mavlink_message_t *msg)
+{
+ mavlink_optical_flow_t packet;
+ mavlink_msg_optical_flow_decode(msg, &packet);
+
+ // record time message was received
+ // ToDo: add jitter correction
+ latest_frame_us = AP_HAL::micros64();
+
+ // add sensor values to sum
+ flow_sum.x += packet.flow_x;
+ flow_sum.y += packet.flow_y;
+ quality_sum += packet.quality;
+ count++;
+
+ // take sensor id from message
+ sensor_id = packet.sensor_id;
+}
diff --git a/libraries/AP_OpticalFlow/AP_OpticalFlow_MAV.h b/libraries/AP_OpticalFlow/AP_OpticalFlow_MAV.h
new file mode 100644
index 00000000000..4a20929cc79
--- /dev/null
+++ b/libraries/AP_OpticalFlow/AP_OpticalFlow_MAV.h
@@ -0,0 +1,34 @@
+#pragma once
+
+#include "OpticalFlow.h"
+#include
+
+class AP_OpticalFlow_MAV : public OpticalFlow_backend
+{
+public:
+ /// constructor
+ using OpticalFlow_backend::OpticalFlow_backend;
+
+ // initialise the sensor
+ void init() override {}
+
+ // read latest values from sensor and fill in x,y and totals.
+ void update(void) override;
+
+ // get update from mavlink
+ void handle_msg(const mavlink_message_t *msg) override;
+
+ // detect if the sensor is available
+ static AP_OpticalFlow_MAV *detect(OpticalFlow &_frontend);
+
+private:
+
+ uint64_t prev_frame_us; // system time of last message when update was last called
+ uint64_t latest_frame_us; // system time of most recent messages processed
+ Vector2l flow_sum; // sum of sensor's flow_x and flow_y values since last call to update
+ uint16_t quality_sum; // sum of sensor's quality values since last call to update
+ uint16_t count; // number of sensor readings since last call to update
+ uint8_t sensor_id; // sensor_id received in latest mavlink message
+ Vector2f gyro_sum; // sum of gyro sensor values since last frame from flow sensor
+ uint16_t gyro_sum_count; // number of gyro sensor values in sum
+};
diff --git a/libraries/AP_OpticalFlow/OpticalFlow.cpp b/libraries/AP_OpticalFlow/OpticalFlow.cpp
index 91ff10a86fe..681e6e89aa0 100644
--- a/libraries/AP_OpticalFlow/OpticalFlow.cpp
+++ b/libraries/AP_OpticalFlow/OpticalFlow.cpp
@@ -5,6 +5,7 @@
#include "AP_OpticalFlow_Pixart.h"
#include "AP_OpticalFlow_PX4Flow.h"
#include "AP_OpticalFlow_CXOF.h"
+#include "AP_OpticalFlow_MAV.h"
#include
extern const AP_HAL::HAL& hal;
@@ -118,6 +119,9 @@ void OpticalFlow::init(uint32_t log_bit)
if (backend == nullptr) {
backend = AP_OpticalFlow_CXOF::detect(*this);
}
+ if (backend == nullptr) {
+ backend = AP_OpticalFlow_MAV::detect(*this);
+ }
}
if (backend != nullptr) {
@@ -140,6 +144,18 @@ void OpticalFlow::update(void)
_flags.healthy = (AP_HAL::millis() - _last_update_ms < 500);
}
+void OpticalFlow::handle_msg(const mavlink_message_t *msg)
+{
+ // exit immediately if not enabled
+ if (!enabled()) {
+ return;
+ }
+
+ if (backend != nullptr) {
+ backend->handle_msg(msg);
+ }
+}
+
void OpticalFlow::update_state(const OpticalFlow_state &state)
{
_state = state;
diff --git a/libraries/AP_OpticalFlow/OpticalFlow.h b/libraries/AP_OpticalFlow/OpticalFlow.h
index 85eabe2bc9b..3d38f3844f1 100644
--- a/libraries/AP_OpticalFlow/OpticalFlow.h
+++ b/libraries/AP_OpticalFlow/OpticalFlow.h
@@ -21,6 +21,7 @@
#include
#include
+#include
class OpticalFlow_backend;
class AP_AHRS_NavEKF;
@@ -53,6 +54,9 @@ public:
// read latest values from sensor and fill in x,y and totals.
void update(void);
+ // handle optical flow mavlink messages
+ void handle_msg(const mavlink_message_t *msg);
+
// quality - returns the surface quality as a measure from 0 ~ 255
uint8_t quality() const { return _state.surface_quality; }
diff --git a/libraries/AP_OpticalFlow/OpticalFlow_backend.h b/libraries/AP_OpticalFlow/OpticalFlow_backend.h
index ba02180a770..1b1124886de 100644
--- a/libraries/AP_OpticalFlow/OpticalFlow_backend.h
+++ b/libraries/AP_OpticalFlow/OpticalFlow_backend.h
@@ -35,6 +35,9 @@ public:
// read latest values from sensor and fill in x,y and totals.
virtual void update() = 0;
+ // handle optical flow mavlink messages
+ virtual void handle_msg(const mavlink_message_t *msg) {}
+
protected:
// access to frontend
OpticalFlow &frontend;