diff --git a/src/drivers/optical_flow/CMakeLists.txt b/src/drivers/optical_flow/CMakeLists.txt
index 6040da0745..4e369805e4 100644
--- a/src/drivers/optical_flow/CMakeLists.txt
+++ b/src/drivers/optical_flow/CMakeLists.txt
@@ -31,5 +31,7 @@
 #
 ############################################################################
 
-add_subdirectory(px4flow)
+add_subdirectory(paw3902)
 add_subdirectory(pmw3901)
+add_subdirectory(px4flow)
+
diff --git a/src/drivers/optical_flow/paw3902/CMakeLists.txt b/src/drivers/optical_flow/paw3902/CMakeLists.txt
new file mode 100644
index 0000000000..04def77b74
--- /dev/null
+++ b/src/drivers/optical_flow/paw3902/CMakeLists.txt
@@ -0,0 +1,41 @@
+############################################################################
+#
+#   Copyright (c) 2019 PX4 Development Team. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in
+#    the documentation and/or other materials provided with the
+#    distribution.
+# 3. Neither the name PX4 nor the names of its contributors may be
+#    used to endorse or promote products derived from this software
+#    without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+# COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+# OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+#
+############################################################################
+
+px4_add_module(
+	MODULE drivers__optical_flow__paw3902
+	MAIN paw3902
+	STACK_MAIN 1500
+	SRCS
+		paw3902_main.cpp
+		PAW3902.cpp
+	)
diff --git a/src/drivers/optical_flow/paw3902/PAW3902.cpp b/src/drivers/optical_flow/paw3902/PAW3902.cpp
new file mode 100644
index 0000000000..73edfca294
--- /dev/null
+++ b/src/drivers/optical_flow/paw3902/PAW3902.cpp
@@ -0,0 +1,705 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2019 PX4 Development Team. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+#include "PAW3902.hpp"
+
+PAW3902::PAW3902(int bus, enum Rotation yaw_rotation) :
+	SPI("PAW3902", nullptr, bus, PAW3902_SPIDEV, SPIDEV_MODE0, PAW3902_SPI_BUS_SPEED),
+	ScheduledWorkItem(px4::device_bus_to_wq(get_device_id())),
+	_sample_perf(perf_alloc(PC_ELAPSED, "paw3902: read")),
+	_interval_perf(perf_alloc(PC_INTERVAL, "paw3902: interval")),
+	_comms_errors(perf_alloc(PC_COUNT, "paw3902: com_err")),
+	_dupe_count_perf(perf_alloc(PC_COUNT, "paw3902: duplicate reading")),
+	_yaw_rotation(yaw_rotation)
+{
+}
+
+PAW3902::~PAW3902()
+{
+	// make sure we are truly inactive
+	stop();
+
+	// free perf counters
+	perf_free(_sample_perf);
+	perf_free(_interval_perf);
+	perf_free(_comms_errors);
+	perf_free(_dupe_count_perf);
+}
+
+
+int
+PAW3902::init()
+{
+	// get yaw rotation from sensor frame to body frame
+	param_t rot = param_find("SENS_FLOW_ROT");
+
+	if (rot != PARAM_INVALID) {
+		int32_t val = 0;
+
+		if (param_get(rot, &val) == PX4_OK) {
+			_yaw_rotation = (enum Rotation)val;
+		}
+	}
+
+	/* For devices competing with NuttX SPI drivers on a bus (Crazyflie SD Card expansion board) */
+	SPI::set_lockmode(LOCK_THREADS);
+
+	/* do SPI init (and probe) first */
+	if (SPI::init() != OK) {
+		return PX4_ERROR;
+	}
+
+	reset();
+
+	// default to low light mode (1)
+	modeLowLight();
+
+	_previous_collect_timestamp = hrt_absolute_time();
+
+	start();
+
+	return PX4_OK;
+}
+
+int
+PAW3902::probe()
+{
+	uint8_t product_id = registerRead(Register::Product_ID);
+
+	PX4_INFO("DEVICE_ID: %X", product_id);
+
+	// Test the SPI communication, checking chipId and inverse chipId
+	if (product_id != PRODUCT_ID) {
+		return PX4_ERROR;
+	}
+
+	uint8_t revision_id = registerRead(Register::Revision_ID);
+	PX4_INFO("REVISION_ID: %X", revision_id);
+
+	if (revision_id != REVISION_ID) {
+		return PX4_ERROR;
+	}
+
+	return PX4_OK;
+}
+
+bool
+PAW3902::reset()
+{
+	// Power on reset
+	registerWrite(Register::Power_Up_Reset, 0x5A);
+	usleep(5000);
+
+	// Read from registers 0x02, 0x03, 0x04, 0x05 and 0x06 one time regardless of the motion state
+	registerRead(Register::Motion);
+	registerRead(Register::Delta_X_L);
+	registerRead(Register::Delta_X_H);
+	registerRead(Register::Delta_Y_L);
+	registerRead(Register::Delta_Y_H);
+
+	usleep(1000);
+
+	return true;
+}
+
+bool
+PAW3902::changeMode(Mode newMode)
+{
+	if (newMode != _mode) {
+		PX4_INFO("changing from mode %d -> %d", static_cast<int>(_mode), static_cast<int>(newMode));
+		ScheduleClear();
+		reset();
+
+		switch (newMode) {
+		case Mode::Bright:
+			modeBright();
+			ScheduleOnInterval(SAMPLE_INTERVAL_MODE_0);
+			break;
+
+		case Mode::LowLight:
+			modeLowLight();
+			ScheduleOnInterval(SAMPLE_INTERVAL_MODE_1);
+			break;
+
+		case Mode::SuperLowLight:
+			modeSuperLowLight();
+			ScheduleOnInterval(SAMPLE_INTERVAL_MODE_2);
+			break;
+		}
+
+		_mode = newMode;
+	}
+
+	// Approximate Resolution = (Register Value + 1) * (50 / 8450) ≈ 0.6% of data point in Figure 19
+	// The maximum register value is 0xA8. The minimum register value is 0.
+	uint8_t resolution = registerRead(Register::Resolution);
+	PX4_INFO("Resolution: %X", resolution);
+	PX4_INFO("Resolution is approx: %.3f", (double)((resolution + 1.0f) * (50.0f / 8450.0f)));
+
+	return true;
+}
+
+bool
+PAW3902::modeBright()
+{
+	// Mode 0: Bright (126 fps) 60 Lux typical
+
+	// set performance optimization registers
+	registerWrite(0x7F, 0x00);
+	registerWrite(0x55, 0x01);
+	registerWrite(0x50, 0x07);
+	registerWrite(0x7f, 0x0e);
+	registerWrite(0x43, 0x10);
+
+	registerWrite(0x48, 0x02);
+	registerWrite(0x7F, 0x00);
+	registerWrite(0x51, 0x7b);
+	registerWrite(0x50, 0x00);
+	registerWrite(0x55, 0x00);
+
+	registerWrite(0x7F, 0x00);
+	registerWrite(0x61, 0xAD);
+	registerWrite(0x7F, 0x03);
+	registerWrite(0x40, 0x00);
+	registerWrite(0x7F, 0x05);
+	registerWrite(0x41, 0xB3);
+	registerWrite(0x43, 0xF1);
+	registerWrite(0x45, 0x14);
+	registerWrite(0x5F, 0x34);
+	registerWrite(0x7B, 0x08);
+	registerWrite(0x5e, 0x34);
+	registerWrite(0x5b, 0x32);
+	registerWrite(0x6d, 0x32);
+	registerWrite(0x45, 0x17);
+	registerWrite(0x70, 0xe5);
+	registerWrite(0x71, 0xe5);
+	registerWrite(0x7F, 0x06);
+	registerWrite(0x44, 0x1B);
+	registerWrite(0x40, 0xBF);
+	registerWrite(0x4E, 0x3F);
+	registerWrite(0x7F, 0x08);
+	registerWrite(0x66, 0x44);
+	registerWrite(0x65, 0x20);
+	registerWrite(0x6a, 0x3a);
+	registerWrite(0x61, 0x05);
+	registerWrite(0x62, 0x05);
+	registerWrite(0x7F, 0x09);
+	registerWrite(0x4F, 0xAF);
+	registerWrite(0x48, 0x80);
+	registerWrite(0x49, 0x80);
+	registerWrite(0x57, 0x77);
+	registerWrite(0x5F, 0x40);
+	registerWrite(0x60, 0x78);
+	registerWrite(0x61, 0x78);
+	registerWrite(0x62, 0x08);
+	registerWrite(0x63, 0x50);
+	registerWrite(0x7F, 0x0A);
+	registerWrite(0x45, 0x60);
+	registerWrite(0x7F, 0x00);
+	registerWrite(0x4D, 0x11);
+	registerWrite(0x55, 0x80);
+	registerWrite(0x74, 0x21);
+	registerWrite(0x75, 0x1F);
+	registerWrite(0x4A, 0x78);
+	registerWrite(0x4B, 0x78);
+	registerWrite(0x44, 0x08);
+	registerWrite(0x45, 0x50);
+	registerWrite(0x64, 0xFE);
+	registerWrite(0x65, 0x1F);
+	registerWrite(0x72, 0x0A);
+	registerWrite(0x73, 0x00);
+	registerWrite(0x7F, 0x14);
+	registerWrite(0x44, 0x84);
+	registerWrite(0x65, 0x47);
+	registerWrite(0x66, 0x18);
+	registerWrite(0x63, 0x70);
+	registerWrite(0x6f, 0x2c);
+	registerWrite(0x7F, 0x15);
+	registerWrite(0x48, 0x48);
+	registerWrite(0x7F, 0x07);
+	registerWrite(0x41, 0x0D);
+	registerWrite(0x43, 0x14);
+	registerWrite(0x4B, 0x0E);
+	registerWrite(0x45, 0x0F);
+	registerWrite(0x44, 0x42);
+	registerWrite(0x4C, 0x80);
+	registerWrite(0x7F, 0x10);
+	registerWrite(0x5B, 0x03);
+	registerWrite(0x7F, 0x07);
+	registerWrite(0x40, 0x41);
+
+	usleep(10_ms); // delay 10ms
+
+	registerWrite(0x7F, 0x00);
+	registerWrite(0x32, 0x00);
+	registerWrite(0x7F, 0x07);
+	registerWrite(0x40, 0x40);
+	registerWrite(0x7F, 0x06);
+	registerWrite(0x68, 0x70);
+	registerWrite(0x69, 0x01);
+	registerWrite(0x7F, 0x0D);
+	registerWrite(0x48, 0xC0);
+	registerWrite(0x6F, 0xD5);
+	registerWrite(0x7F, 0x00);
+	registerWrite(0x5B, 0xA0);
+	registerWrite(0x4E, 0xA8);
+	registerWrite(0x5A, 0x50);
+	registerWrite(0x40, 0x80);
+	registerWrite(0x73, 0x1f);
+
+	usleep(10_ms); // delay 10ms
+
+	registerWrite(0x73, 0x00);
+
+	return false;
+}
+
+bool
+PAW3902::modeLowLight()
+{
+	// Mode 1: Low Light (126 fps) 30 Lux typical
+	// low light and low speed motion tracking
+
+	// set performance optimization registers
+	registerWrite(0x7F, 0x00);
+	registerWrite(0x55, 0x01);
+	registerWrite(0x50, 0x07);
+	registerWrite(0x7f, 0x0e);
+	registerWrite(0x43, 0x10);
+
+	registerWrite(0x48, 0x02);
+	registerWrite(0x7F, 0x00);
+	registerWrite(0x51, 0x7b);
+	registerWrite(0x50, 0x00);
+	registerWrite(0x55, 0x00);
+
+	registerWrite(0x7F, 0x00);
+	registerWrite(0x61, 0xAD);
+	registerWrite(0x7F, 0x03);
+	registerWrite(0x40, 0x00);
+	registerWrite(0x7F, 0x05);
+	registerWrite(0x41, 0xB3);
+	registerWrite(0x43, 0xF1);
+	registerWrite(0x45, 0x14);
+	registerWrite(0x5F, 0x34);
+	registerWrite(0x7B, 0x08);
+	registerWrite(0x5e, 0x34);
+	registerWrite(0x5b, 0x65);
+	registerWrite(0x6d, 0x65);
+	registerWrite(0x45, 0x17);
+	registerWrite(0x70, 0xe5);
+	registerWrite(0x71, 0xe5);
+	registerWrite(0x7F, 0x06);
+	registerWrite(0x44, 0x1B);
+	registerWrite(0x40, 0xBF);
+	registerWrite(0x4E, 0x3F);
+	registerWrite(0x7F, 0x08);
+	registerWrite(0x66, 0x44);
+	registerWrite(0x65, 0x20);
+	registerWrite(0x6a, 0x3a);
+	registerWrite(0x61, 0x05);
+	registerWrite(0x62, 0x05);
+	registerWrite(0x7F, 0x09);
+	registerWrite(0x4F, 0xAF);
+	registerWrite(0x48, 0x80);
+	registerWrite(0x49, 0x80);
+	registerWrite(0x57, 0x77);
+	registerWrite(0x5F, 0x40);
+	registerWrite(0x60, 0x78);
+	registerWrite(0x61, 0x78);
+	registerWrite(0x62, 0x08);
+	registerWrite(0x63, 0x50);
+	registerWrite(0x7F, 0x0A);
+	registerWrite(0x45, 0x60);
+	registerWrite(0x7F, 0x00);
+	registerWrite(0x4D, 0x11);
+	registerWrite(0x55, 0x80);
+	registerWrite(0x74, 0x21);
+	registerWrite(0x75, 0x1F);
+	registerWrite(0x4A, 0x78);
+	registerWrite(0x4B, 0x78);
+	registerWrite(0x44, 0x08);
+	registerWrite(0x45, 0x50);
+	registerWrite(0x64, 0xFE);
+	registerWrite(0x65, 0x1F);
+	registerWrite(0x72, 0x0A);
+	registerWrite(0x73, 0x00);
+	registerWrite(0x7F, 0x14);
+	registerWrite(0x44, 0x84);
+	registerWrite(0x65, 0x67);
+	registerWrite(0x66, 0x18);
+	registerWrite(0x63, 0x70);
+	registerWrite(0x6f, 0x2c);
+	registerWrite(0x7F, 0x15);
+	registerWrite(0x48, 0x48);
+	registerWrite(0x7F, 0x07);
+	registerWrite(0x41, 0x0D);
+	registerWrite(0x43, 0x14);
+	registerWrite(0x4B, 0x0E);
+	registerWrite(0x45, 0x0F);
+	registerWrite(0x44, 0x42);
+	registerWrite(0x4C, 0x80);
+	registerWrite(0x7F, 0x10);
+	registerWrite(0x5B, 0x03);
+	registerWrite(0x7F, 0x07);
+	registerWrite(0x40, 0x41);
+
+	usleep(10_ms); // delay 10ms
+
+	registerWrite(0x7F, 0x00);
+	registerWrite(0x32, 0x00);
+	registerWrite(0x7F, 0x07);
+	registerWrite(0x40, 0x40);
+	registerWrite(0x7F, 0x06);
+	registerWrite(0x68, 0x70);
+	registerWrite(0x69, 0x01);
+	registerWrite(0x7F, 0x0D);
+	registerWrite(0x48, 0xC0);
+	registerWrite(0x6F, 0xD5);
+	registerWrite(0x7F, 0x00);
+	registerWrite(0x5B, 0xA0);
+	registerWrite(0x4E, 0xA8);
+	registerWrite(0x5A, 0x50);
+	registerWrite(0x40, 0x80);
+	registerWrite(0x73, 0x1f);
+
+	usleep(10_ms); // delay 10ms
+
+	registerWrite(0x73, 0x00);
+
+	return false;
+}
+
+bool
+PAW3902::modeSuperLowLight()
+{
+	// Mode 2: Super Low Light (50 fps) 9 Lux typical
+	// super low light and low speed motion tracking
+
+	// set performance optimization registers
+	registerWrite(0x7F, 0x00);
+	registerWrite(0x55, 0x01);
+	registerWrite(0x50, 0x07);
+	registerWrite(0x7f, 0x0e);
+	registerWrite(0x43, 0x10);
+
+	registerWrite(0x48, 0x04);
+	registerWrite(0x7F, 0x00);
+	registerWrite(0x51, 0x7b);
+	registerWrite(0x50, 0x00);
+	registerWrite(0x55, 0x00);
+
+	registerWrite(0x7F, 0x00);
+	registerWrite(0x61, 0xAD);
+	registerWrite(0x7F, 0x03);
+	registerWrite(0x40, 0x00);
+	registerWrite(0x7F, 0x05);
+	registerWrite(0x41, 0xB3);
+	registerWrite(0x43, 0xF1);
+	registerWrite(0x45, 0x14);
+	registerWrite(0x5F, 0x34);
+	registerWrite(0x7B, 0x08);
+	registerWrite(0x5E, 0x34);
+	registerWrite(0x5B, 0x32);
+	registerWrite(0x6D, 0x32);
+	registerWrite(0x45, 0x17);
+	registerWrite(0x70, 0xE5);
+	registerWrite(0x71, 0xE5);
+	registerWrite(0x7F, 0x06);
+	registerWrite(0x44, 0x1B);
+	registerWrite(0x40, 0xBF);
+	registerWrite(0x4E, 0x3F);
+	registerWrite(0x7F, 0x08);
+	registerWrite(0x66, 0x44);
+	registerWrite(0x65, 0x20);
+	registerWrite(0x6A, 0x3a);
+	registerWrite(0x61, 0x05);
+	registerWrite(0x62, 0x05);
+	registerWrite(0x7F, 0x09);
+	registerWrite(0x4F, 0xAF);
+	registerWrite(0x48, 0x80);
+	registerWrite(0x49, 0x80);
+	registerWrite(0x57, 0x77);
+	registerWrite(0x5F, 0x40);
+	registerWrite(0x60, 0x78);
+	registerWrite(0x61, 0x78);
+	registerWrite(0x62, 0x08);
+	registerWrite(0x63, 0x50);
+	registerWrite(0x7F, 0x0A);
+	registerWrite(0x45, 0x60);
+	registerWrite(0x7F, 0x00);
+	registerWrite(0x4D, 0x11);
+	registerWrite(0x55, 0x80);
+	registerWrite(0x74, 0x21);
+	registerWrite(0x75, 0x1F);
+	registerWrite(0x4A, 0x78);
+	registerWrite(0x4B, 0x78);
+	registerWrite(0x44, 0x08);
+	registerWrite(0x45, 0x50);
+	registerWrite(0x64, 0xCE);
+	registerWrite(0x65, 0x0B);
+	registerWrite(0x72, 0x0A);
+	registerWrite(0x73, 0x00);
+	registerWrite(0x7F, 0x14);
+	registerWrite(0x44, 0x84);
+	registerWrite(0x65, 0x67);
+	registerWrite(0x66, 0x18);
+	registerWrite(0x63, 0x70);
+	registerWrite(0x6f, 0x2c);
+	registerWrite(0x7F, 0x15);
+	registerWrite(0x48, 0x48);
+	registerWrite(0x7F, 0x07);
+	registerWrite(0x41, 0x0D);
+	registerWrite(0x43, 0x14);
+	registerWrite(0x4B, 0x0E);
+	registerWrite(0x45, 0x0F);
+	registerWrite(0x44, 0x42);
+	registerWrite(0x4C, 0x80);
+	registerWrite(0x7F, 0x10);
+	registerWrite(0x5B, 0x02);
+	registerWrite(0x7F, 0x07);
+	registerWrite(0x40, 0x41);
+
+	usleep(25_ms); // delay 25ms
+
+	registerWrite(0x7F, 0x00);
+	registerWrite(0x32, 0x44);
+	registerWrite(0x7F, 0x07);
+	registerWrite(0x40, 0x40);
+	registerWrite(0x7F, 0x06);
+	registerWrite(0x68, 0x40);
+	registerWrite(0x69, 0x02);
+	registerWrite(0x7F, 0x0D);
+	registerWrite(0x48, 0xC0);
+	registerWrite(0x6F, 0xD5);
+	registerWrite(0x7F, 0x00);
+	registerWrite(0x5B, 0xA0);
+	registerWrite(0x4E, 0xA8);
+	registerWrite(0x5A, 0x50);
+	registerWrite(0x40, 0x80);
+	registerWrite(0x73, 0x0B);
+
+	usleep(25_ms); // delay 25ms
+
+	registerWrite(0x73, 0x00);
+
+	return true;
+}
+
+uint8_t
+PAW3902::registerRead(uint8_t reg)
+{
+	uint8_t cmd[2] {};
+	cmd[0] = reg;
+	transfer(&cmd[0], &cmd[0], sizeof(cmd));
+	up_udelay(T_SRR);
+	return cmd[1];
+}
+
+void
+PAW3902::registerWrite(uint8_t reg, uint8_t data)
+{
+	uint8_t cmd[2];
+	cmd[0] = DIR_WRITE(reg);
+	cmd[1] = data;
+	transfer(&cmd[0], nullptr, sizeof(cmd));
+	up_udelay(T_SWW);
+}
+
+void
+PAW3902::Run()
+{
+	perf_begin(_sample_perf);
+	perf_count(_interval_perf);
+
+	struct TransferBuffer {
+		uint8_t cmd = Register::Motion_Burst;
+		BURST_TRANSFER data{};
+	};
+	TransferBuffer buf;
+	static_assert(sizeof(buf) == (12 + 1));
+
+	const hrt_abstime timestamp_sample = hrt_absolute_time();
+
+	if (transfer((uint8_t *)&buf, (uint8_t *)&buf, sizeof(buf)) != PX4_OK) {
+		perf_count(_comms_errors);
+		perf_end(_sample_perf);
+		return;
+	}
+
+	const uint64_t dt_flow = timestamp_sample - _previous_collect_timestamp;
+	_flow_dt_sum_usec += dt_flow;
+	_frame_count_since_last++;
+
+	// update for next iteration
+	_previous_collect_timestamp = timestamp_sample;
+
+	// PX4_INFO("data.Motion %d", buf.data.Motion);
+	// PX4_INFO("data.Observation %d", buf.data.Observation);
+	// PX4_INFO("data.Delta_X_L %d", buf.data.Delta_X_L);
+	// PX4_INFO("data.Delta_X_H %d", buf.data.Delta_X_H);
+	// PX4_INFO("data.Delta_Y_L %d", buf.data.Delta_Y_L);
+	// PX4_INFO("data.Delta_Y_H %d", buf.data.Delta_Y_H);
+	// PX4_INFO("data.SQUAL %d", buf.data.SQUAL);
+	// PX4_INFO("data.RawData_Sum %d", buf.data.RawData_Sum);
+	// PX4_INFO("data.Maximum_RawData %d", buf.data.Maximum_RawData);
+	// PX4_INFO("data.Minimum_RawData %d", buf.data.Minimum_RawData);
+	// PX4_INFO("data.Shutter_Upper %d", buf.data.Shutter_Upper);
+	// PX4_INFO("data.Shutter_Lower %d", buf.data.Shutter_Lower);
+
+	const int16_t delta_x_raw = ((int16_t)buf.data.Delta_X_H << 8) | buf.data.Delta_X_L;
+	const int16_t delta_y_raw = ((int16_t)buf.data.Delta_Y_H << 8) | buf.data.Delta_Y_L;
+
+	// check SQUAL & Shutter values
+	// To suppress false motion reports, discard Delta X and Delta Y values if the SQUAL and Shutter values meet the condition
+	// Bright Mode,			SQUAL < 0x19, Shutter ≥ 0x1FF0
+	// Low Light Mode,		SQUAL < 0x46, Shutter ≥ 0x1FF0
+	// Super Low Light Mode,	SQUAL < 0x55, Shutter ≥ 0x0BC0
+	const uint16_t shutter = (buf.data.Shutter_Upper << 8) | buf.data.Shutter_Lower;
+
+	if ((buf.data.SQUAL < 0x19) && (shutter >= 0x0BC0)) {
+		PX4_ERR("false motion report, discarding");
+		perf_end(_sample_perf);
+		return;
+	}
+
+	switch (_mode) {
+	case Mode::Bright:
+		if ((shutter >= 0x1FFE) && (buf.data.RawData_Sum < 0x3C)) { // AND valid for 10 consecutive frames?
+			// Bright -> LowLight
+			changeMode(Mode::LowLight);
+		}
+
+		break;
+
+	case Mode::LowLight:
+		if ((shutter >= 0x1FFE) && (buf.data.RawData_Sum < 0x5A)) {	// AND valid for 10 consecutive frames?
+			// LowLight -> SuperLowLight
+			changeMode(Mode::SuperLowLight);
+
+		} else if ((shutter >= 0x0BB8)) {	// AND valid for 10 consecutive frames?
+			// LowLight -> Bright
+			changeMode(Mode::Bright);
+		}
+
+		break;
+
+	case Mode::SuperLowLight:
+
+		// SuperLowLight -> LowLight
+		if ((shutter >= 0x03E8)) { // AND valid for 10 consecutive frames?
+			changeMode(Mode::LowLight);
+		}
+
+		// PAW3902JF should not operate with Shutter < 0x01F4 in Mode 2
+		if (shutter >= 0x01F4) {
+			changeMode(Mode::LowLight);
+		}
+
+		break;
+	}
+
+	// TODO: page 35 switching scheme
+
+	// As a minimum requirement, PAW3902JF should not operate with Shutter < 0x01F4 in Mode 2, and must switch to the next operation mode.
+
+	_flow_sum_x += delta_x_raw;
+	_flow_sum_y += delta_y_raw;
+
+	// returns if the collect time has not been reached
+	if (_flow_dt_sum_usec < _collect_time) {
+		perf_end(_sample_perf);
+		return;
+	}
+
+	optical_flow_s report{};
+	report.timestamp = timestamp_sample;
+
+
+	//PX4_INFO("X: %d Y: %d", _flow_sum_x, _flow_sum_y);
+
+	report.pixel_flow_x_integral = (float)_flow_sum_x / 500.0f;	// proportional factor + convert from pixels to radians
+	report.pixel_flow_y_integral = (float)_flow_sum_y / 500.0f;	// proportional factor + convert from pixels to radians
+
+	// rotate measurements in yaw from sensor frame to body frame according to parameter SENS_FLOW_ROT
+	float zeroval = 0.0f;
+	rotate_3f(_yaw_rotation, report.pixel_flow_x_integral, report.pixel_flow_y_integral, zeroval);
+
+	report.frame_count_since_last_readout = _frame_count_since_last;
+	report.integration_timespan = _flow_dt_sum_usec;	// microseconds
+
+	report.sensor_id = 0;
+	report.quality = buf.data.SQUAL;
+
+	/* No gyro on this board */
+	report.gyro_x_rate_integral = NAN;
+	report.gyro_y_rate_integral = NAN;
+	report.gyro_z_rate_integral = NAN;
+
+	// set (conservative) specs according to datasheet
+	report.max_flow_rate = 5.0f;       // Datasheet: 7.4 rad/s
+	report.min_ground_distance = 0.08f; // Datasheet: 80mm
+	report.max_ground_distance = 30.0f; // Datasheet: infinity
+
+	_optical_flow_pub.publish(report);
+
+	// reset
+	_flow_dt_sum_usec = 0;
+	_flow_sum_x = 0;
+	_flow_sum_y = 0;
+	_frame_count_since_last = 0;
+
+	perf_end(_sample_perf);
+}
+
+void
+PAW3902::start()
+{
+	// schedule a cycle to start things
+	ScheduleOnInterval(SAMPLE_INTERVAL_MODE_1);
+}
+
+void
+PAW3902::stop()
+{
+	ScheduleClear();
+}
+
+void
+PAW3902::print_info()
+{
+	perf_print_counter(_sample_perf);
+	perf_print_counter(_interval_perf);
+	perf_print_counter(_comms_errors);
+	perf_print_counter(_dupe_count_perf);
+}
diff --git a/src/drivers/optical_flow/paw3902/PAW3902.hpp b/src/drivers/optical_flow/paw3902/PAW3902.hpp
new file mode 100644
index 0000000000..483e5b8798
--- /dev/null
+++ b/src/drivers/optical_flow/paw3902/PAW3902.hpp
@@ -0,0 +1,140 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2019 PX4 Development Team. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/**
+ * @file paw3902.cpp
+ *
+ * Driver for the Pixart PAW3902 optical flow sensor connected via SPI.
+ */
+
+#pragma once
+
+#include "PixArt_PAW3902JF_Registers.hpp"
+
+#include <px4_config.h>
+#include <px4_defines.h>
+#include <px4_getopt.h>
+#include <px4_work_queue/ScheduledWorkItem.hpp>
+#include <drivers/device/spi.h>
+#include <conversion/rotation.h>
+#include <lib/perf/perf_counter.h>
+#include <lib/parameters/param.h>
+#include <drivers/drv_hrt.h>
+#include <drivers/drv_range_finder.h>
+#include <uORB/Publication.hpp>
+#include <uORB/topics/optical_flow.h>
+
+/* Configuration Constants */
+
+#if defined PX4_SPI_BUS_EXPANSION   // crazyflie
+# define PAW3902_BUS PX4_SPI_BUS_EXPANSION
+#elif defined PX4_SPI_BUS_EXTERNAL1   // fmu-v5
+# define PAW3902_BUS PX4_SPI_BUS_EXTERNAL1
+#elif defined PX4_SPI_BUS_EXTERNAL    // fmu-v4 extspi
+# define PAW3902_BUS PX4_SPI_BUS_EXTERNAL
+#else
+# error "add the required spi bus from board_config.h here"
+#endif
+
+#if defined PX4_SPIDEV_EXPANSION_2    // crazyflie flow deck
+# define PAW3902_SPIDEV PX4_SPIDEV_EXPANSION_2
+#elif defined PX4_SPIDEV_EXTERNAL1_1    // fmu-v5 ext CS1
+# define PAW3902_SPIDEV PX4_SPIDEV_EXTERNAL1_1
+#elif defined PX4_SPIDEV_EXTERNAL   // fmu-v4 extspi
+# define PAW3902_SPIDEV PX4_SPIDEV_EXTERNAL
+#else
+# error "add the required spi dev from board_config.h here"
+#endif
+
+#define PAW3902_SPI_BUS_SPEED (2000000L) // 2MHz
+
+#define DIR_WRITE(a) ((a) | (1 << 7))
+#define DIR_READ(a) ((a) & 0x7f)
+
+using namespace time_literals;
+using namespace PixArt_PAW3902JF;
+
+// PAW3902JF-TXQT is PixArt Imaging
+
+class PAW3902 : public device::SPI, public px4::ScheduledWorkItem
+{
+public:
+	PAW3902(int bus = PAW3902_BUS, enum Rotation yaw_rotation = ROTATION_NONE);
+	virtual ~PAW3902();
+
+	virtual int init();
+
+	void print_info();
+
+	void start();
+	void stop();
+
+protected:
+	virtual int probe();
+
+private:
+
+	void Run() override;
+
+	uint8_t	registerRead(uint8_t reg);
+	void	registerWrite(uint8_t reg, uint8_t data);
+
+	bool reset();
+
+	bool modeBright();
+	bool modeLowLight();
+	bool modeSuperLowLight();
+
+	bool changeMode(Mode newMode);
+
+	uORB::Publication<optical_flow_s> _optical_flow_pub{ORB_ID(optical_flow)};
+
+	perf_counter_t	_sample_perf;
+	perf_counter_t	_interval_perf;
+	perf_counter_t	_comms_errors;
+	perf_counter_t	_dupe_count_perf;
+
+	static constexpr uint64_t _collect_time{15000}; // 15 milliseconds, optical flow data publish rate
+
+	uint64_t	_previous_collect_timestamp{0};
+	uint64_t	_flow_dt_sum_usec{0};
+	unsigned	_frame_count_since_last{0};
+
+	enum Rotation	_yaw_rotation {ROTATION_NONE};
+
+	int		_flow_sum_x{0};
+	int		_flow_sum_y{0};
+
+	Mode		_mode{Mode::LowLight};
+
+};
diff --git a/src/drivers/optical_flow/paw3902/PixArt_PAW3902JF_Registers.hpp b/src/drivers/optical_flow/paw3902/PixArt_PAW3902JF_Registers.hpp
new file mode 100644
index 0000000000..8dcbf626af
--- /dev/null
+++ b/src/drivers/optical_flow/paw3902/PixArt_PAW3902JF_Registers.hpp
@@ -0,0 +1,99 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2019 PX4 Development Team. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+#pragma once
+
+namespace PixArt_PAW3902JF
+{
+
+static constexpr uint8_t PRODUCT_ID = 0x49;	// shared with the PMW3901
+static constexpr uint8_t REVISION_ID = 0x01;
+
+static constexpr uint32_t SAMPLE_INTERVAL_MODE_0{1000000 / 126};	// 126 fps
+static constexpr uint32_t SAMPLE_INTERVAL_MODE_1{1000000 / 126};	// 126 fps
+static constexpr uint32_t SAMPLE_INTERVAL_MODE_2{1000000 / 50};		// 50 fps
+
+static constexpr uint64_t T_SWW{11};	// 10.5 microseconds
+static constexpr uint64_t T_SRR{2};	// 1.5 microseconds
+
+enum Register : uint8_t {
+	Product_ID	= 0x00,
+	Revision_ID	= 0x01,
+	Motion		= 0x02,
+	Delta_X_L	= 0x03,
+	Delta_X_H	= 0x04,
+	Delta_Y_L	= 0x05,
+	Delta_Y_H	= 0x06,
+	Squal		= 0x07,
+	RawData_Sum	= 0x08,
+	Maximum_RawData	= 0x09,
+	Minimum_RawData	= 0x0A,
+	Shutter_Lower	= 0x0B,
+	Shutter_Upper	= 0x0C,
+
+	Observation	= 0x15,
+	Motion_Burst	= 0x16,
+
+	Power_Up_Reset	= 0x3A,
+
+	Resolution	= 0x4E,
+
+};
+
+enum Product_ID_Bit : uint8_t {
+	Reset = 0x5A,
+};
+
+
+enum class Mode {
+	Bright = 0,
+	LowLight = 1,
+	SuperLowLight = 2,
+};
+
+struct BURST_TRANSFER {
+	uint8_t Motion;
+	uint8_t Observation;
+	uint8_t Delta_X_L;
+	uint8_t Delta_X_H;
+	uint8_t Delta_Y_L;
+	uint8_t Delta_Y_H;
+	uint8_t SQUAL;
+	uint8_t RawData_Sum;
+	uint8_t Maximum_RawData;
+	uint8_t Minimum_RawData;
+	uint8_t Shutter_Upper;
+	uint8_t Shutter_Lower;
+};
+
+}
diff --git a/src/drivers/optical_flow/paw3902/paw3902_main.cpp b/src/drivers/optical_flow/paw3902/paw3902_main.cpp
new file mode 100644
index 0000000000..ce8e1c075e
--- /dev/null
+++ b/src/drivers/optical_flow/paw3902/paw3902_main.cpp
@@ -0,0 +1,190 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2019 PX4 Development Team. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+#include "PAW3902.hpp"
+
+/**
+ * Local functions in support of the shell command.
+ */
+namespace pmw3902
+{
+
+PAW3902	*g_dev;
+
+void	start(int spi_bus);
+void	stop();
+void	test();
+void	reset();
+void	info();
+void	usage();
+
+
+/**
+ * Start the driver.
+ */
+void
+start(int spi_bus)
+{
+	if (g_dev != nullptr) {
+		errx(1, "already started");
+	}
+
+	/* create the driver */
+	g_dev = new PAW3902(spi_bus, (enum Rotation)0);
+
+	if (g_dev == nullptr) {
+		goto fail;
+	}
+
+	if (OK != g_dev->init()) {
+		goto fail;
+	}
+
+	exit(0);
+
+fail:
+
+	if (g_dev != nullptr) {
+		delete g_dev;
+		g_dev = nullptr;
+	}
+
+	errx(1, "driver start failed");
+}
+
+/**
+ * Stop the driver
+ */
+void stop()
+{
+	if (g_dev != nullptr) {
+		delete g_dev;
+		g_dev = nullptr;
+
+	} else {
+		errx(1, "driver not running");
+	}
+
+	exit(0);
+}
+
+/**
+ * Print a little info about the driver.
+ */
+void
+info()
+{
+	if (g_dev == nullptr) {
+		errx(1, "driver not running");
+	}
+
+	printf("state @ %p\n", g_dev);
+	g_dev->print_info();
+
+	exit(0);
+}
+
+/**
+ * Print a little info about how to start/stop/use the driver
+ */
+void usage()
+{
+	PX4_INFO("usage: pmw3902 {start|test|reset|info'}");
+	PX4_INFO("    [-b SPI_BUS]");
+}
+
+} // namespace pmw3902
+
+/*
+ * Driver 'main' command.
+ */
+extern "C" __EXPORT int paw3902_main(int argc, char *argv[]);
+
+int
+paw3902_main(int argc, char *argv[])
+{
+	if (argc < 2) {
+		pmw3902::usage();
+		return PX4_ERROR;
+	}
+
+	// don't exit from getopt loop to leave getopt global variables in consistent state,
+	// set error flag instead
+	bool err_flag = false;
+	int ch;
+	int myoptind = 1;
+	const char *myoptarg = nullptr;
+	int spi_bus = PAW3902_BUS;
+
+	while ((ch = px4_getopt(argc, argv, "b:", &myoptind, &myoptarg)) != EOF) {
+		switch (ch) {
+		case 'b':
+			spi_bus = (uint8_t)atoi(myoptarg);
+
+			break;
+
+		default:
+			err_flag = true;
+			break;
+		}
+	}
+
+	if (err_flag) {
+		pmw3902::usage();
+		return PX4_ERROR;
+	}
+
+	/*
+	 * Start/load the driver.
+	 */
+	if (!strcmp(argv[myoptind], "start")) {
+		pmw3902::start(spi_bus);
+	}
+
+	/*
+	 * Stop the driver
+	 */
+	if (!strcmp(argv[myoptind], "stop")) {
+		pmw3902::stop();
+	}
+
+	/*
+	 * Print driver information.
+	 */
+	if (!strcmp(argv[myoptind], "status")) {
+		pmw3902::info();
+	}
+
+	pmw3902::usage();
+	return PX4_ERROR;
+}
diff --git a/src/drivers/optical_flow/pmw3901/CMakeLists.txt b/src/drivers/optical_flow/pmw3901/CMakeLists.txt
index c41c197c7d..bdead0107e 100644
--- a/src/drivers/optical_flow/pmw3901/CMakeLists.txt
+++ b/src/drivers/optical_flow/pmw3901/CMakeLists.txt
@@ -32,7 +32,7 @@
 ############################################################################
 
 px4_add_module(
-	MODULE drivers__pmw3901
+	MODULE drivers__optical_flow__pmw3901
 	MAIN pmw3901
 	COMPILE_FLAGS
 		-Wno-cast-align # TODO: fix and enable