Disable log as it may crash the program

(Setting alpha = 1 efficiently disables the filter.)
Filtering does more harm than good in voltage monitoring.

.github/workflows/build.yml

@@ -27,6 +27,8 @@ jobs:
       run: make BOARD=esp32:esp32:esp32c3
     - name: Build firmware for ESP32-S3
       run: make BOARD=esp32:esp32:esp32s3
+    - name: Build espnow-proxy
+      run: arduino-cli compile --fqbn esp32:esp32:esp32 tools/espnow-proxy
     - name: Check c_cpp_properties.json
       run: tools/check_c_cpp_properties.py
 

Makefile

@@ -1,10 +1,10 @@
-BOARD = esp32:esp32:d1_mini32:DebugLevel=error
+BOARD = esp32:esp32:d1_mini32
 PORT := $(strip $(wildcard /dev/serial/by-id/usb-Silicon_Labs_CP21* /dev/serial/by-id/usb-1a86_USB_Single_Serial_* /dev/cu.usbserial-* /dev/cu.usbmodem*))
 
 export ARDUINO_NETWORK_CONNECTION_TIMEOUT := 1h
 
 build: .core .libs
-	arduino-cli compile --fqbn $(BOARD) flix
+	arduino-cli compile --fqbn $(BOARD) --build-property "build.core_debug_level=1" flix
 
 upload: build
 	arduino-cli upload --fqbn $(BOARD) -p "$(PORT)" flix

docs/usage.md

@@ -25,7 +25,7 @@ You can build and upload the firmware using either **Arduino IDE** (easier for b
    * `FlixPeriph`, the latest version.
    * `MAVLink`, version 2.0.25.
 5. Open the `flix/flix.ino` sketch from downloaded firmware sources in Arduino IDE.
-6. Connect your ESP32 board to the computer and choose correct board type in Arduino IDE (*WEMOS D1 MINI ESP32* for ESP32 Mini) and the port.
+6. Connect your ESP32 board to the computer and choose correct board type in Arduino IDE (*WEMOS D1 MINI ESP32* for ESP32 Mini, *ESP32S3 Dev Module* for ESP32-S3 Super Mini) and the port.
 7. Set *Tools* ⇒ *Core Debug Level* to *Error* to see the errors in the serial console. Set *Tools* ⇒ *USB CDC on Boot* to *Enabled* for ESP32-S3/ESP32-C3 boards.
 8. [Build and upload](https://docs.arduino.cc/software/ide-v2/tutorials/getting-started/ide-v2-uploading-a-sketch) the firmware using Arduino IDE.
 
@@ -61,7 +61,7 @@ You can build and upload the firmware using either **Arduino IDE** (easier for b
    For ESP32-S3/ESP32-C3 boards, set the appropriate [FQBN](https://docs.arduino.cc/arduino-cli/FAQ/#whats-the-fqbn-string) using `BOARD` parameter:
 
    ```bash
-   make BOARD=esp32:esp32:esp32s3:DebugLevel=error,FlashSize=4M,CDCOnBoot=cdc upload
+   make BOARD=esp32:esp32:esp32s3:FlashSize=4M,CDCOnBoot=cdc upload
    ```
 
 See other available Make commands in [Makefile](../Makefile).
@@ -77,9 +77,26 @@ In case if using different IMU model than MPU9250, change `imu` variable declara
 
 ```cpp
 ICM20948 imu(SPI);  // For ICM-20948
+// or
 MPU6050 imu(Wire);  // For MPU-6050
 ```
 
+If using non-default SPI pins, pass SCK, MISO, and MOSI pin numbers to `SPI.begin` call and SS pin to `imu` constructor like that:
+
+```cpp
+ICM20948(SPI, <SS>);
+// ...
+SPI.begin(<SCK>, <MISO>, <MOSI>);
+imu.begin();
+```
+
+If using non-default I2C pins, pass SDA and SCL pin numbers to `Wire.setPins` call like that:
+
+```cpp
+Wire.begin(<SDA>, <SCL>);
+imu.begin();
+```
+
 ### Connect using QGroundControl
 
 QGroundControl is a ground control station software that can be used to monitor and control the drone.
@@ -105,7 +122,7 @@ To access the console using serial port:
 To access the console using QGroundControl:
 
 1. Connect to the drone using QGroundControl app.
-2. Go to the QGroundControl menu ⇒ *Vehicle Setup* ⇒ *Analyze Tools* ⇒ *MAVLink Console*.
+2. Go to the QGroundControl menu ⇒ *Analyze Tools* ⇒ *MAVLink Console*.
 
 <img src="img/cli.png" width="400">
 
@@ -333,7 +350,7 @@ To setup ESP-NOW communication:
 
 1. Flash the second ESP32 board with ESP-NOW proxy sketch: [`tools/espnow-proxy/espnow-proxy.ino`](../tools/espnow-proxy/espnow-proxy.ino). Use Arduino IDE or command line: `make upload_proxy`.
 
-2. Open Serial Monitor or use `make monitor` command. The ESP32 will print its MAC address and generated encryption key, for example:
+2. Open Serial Monitor in Arduino IDE or use `make monitor` command. The ESP32 will print its MAC address and generated encryption key, for example:
 
    ```
    espnow 7a:c8:e3:eb:bf:e9 &PiuSysxP9+$L&5E
@@ -352,7 +369,10 @@ To setup ESP-NOW communication:
    * Type: Serial.
    * Serial Port: choose the port of the proxy ESP32 board, e. g. `/dev/cu.usbserial-0001`.
    * Baud Rate: 115200.
-5. Click *Save*. QGroundControl should connect to the drone using ESP-NOW and begin showing the telemetry.
+5. Click *Save*, click *Connect*. QGroundControl should connect to the drone using ESP-NOW and begin showing the telemetry.
+
+> [!TIP]
+> Make sure Arduino IDE is not running when using ESP-NOW proxy board, as it may block it.
 
 ## Flight log
 

flix/cli.ino

@@ -6,7 +6,7 @@
 #include "pid.h"
 #include "vector.h"
 #include "util.h"
-#include "lpf.h"
+#include "filter.h"
 
 extern const int MOTOR_REAR_LEFT, MOTOR_REAR_RIGHT, MOTOR_FRONT_RIGHT, MOTOR_FRONT_LEFT;
 extern const int RAW, ACRO, STAB, AUTO;
@@ -50,8 +50,14 @@ const char* motd =
 "sta <ssid> <password> - configure Wi-Fi client mode\n"
 "espnow <mac> [<key>] - configure ESP-NOW peer\n"
 "mot - show motor output\n"
-"log [dump] - print log header [and data]\n"
 "mfr/mfl/mrr/mrl [<thrust>] - test motor (remove props)\n"
+"log [dump] - print log header [and data]\n"
+"log - show log info\n"
+"log header - show log header\n"
+"log reset - reset log\n"
+"log <name> <rate> - setup log topic rate\n"
+"l <str> - show log values starting with str\n"
+"l expose <name> - expose log value to telemetry\n"
 "sys - show system info\n"
 "reset - reset drone's state\n"
 "reboot - reboot the drone\n";
@@ -153,9 +159,18 @@ void doCommand(String str, bool echo = false) {
 	} else if (command == "mot") {
 		print("front-right %g front-left %g rear-right %g rear-left %g\n",
 			motors[MOTOR_FRONT_RIGHT], motors[MOTOR_FRONT_LEFT], motors[MOTOR_REAR_RIGHT], motors[MOTOR_REAR_LEFT]);
-	} else if (command == "log") {
+	} else if (command == "log" && arg0 == "") {
+		printLogInfo();
+	} else if (command == "log" && arg1 != "") {
+		configLogThrottle(arg0.c_str(), arg1.toFloat());
+	} else if (command == "log" && arg0 == "header") {
 		printLogHeader();
-		if (arg0 == "dump") printLogData();
+	} else if (command == "log" && arg0 == "reset") {
+		resetLog();
+	} else if (command == "l" && arg0 == "expose" && arg1 != "") {
+		exposeLogValue(arg1.c_str());
+	} else if (command == "l") {
+		printLogValues(arg0.c_str());
 	} else if (command == "cr") {
 		calibrateRC();
 	} else if (command == "ca") {
@@ -174,6 +189,8 @@ void doCommand(String str, bool echo = false) {
 		print("Temperature: %.1f °C\n", temperatureRead());
 		print("Total RAM: %d KB\n", ESP.getHeapSize() / 1024);
 		print("Free heap: %d KB\n", ESP.getFreeHeap() / 1024);
+		print("PSRAM: %d KB\n", ESP.getPsramSize() / 1024);
+		print("Free PSRAM: %d KB\n", ESP.getFreePsram() / 1024);
 		print("Firmware: " __DATE__ " " __TIME__ "\n");
 		// Print tasks table
 		print("Num  Task                MinSt  Prio  Core  CPU%%\n");

flix/control.ino

@@ -6,7 +6,7 @@
 #include "vector.h"
 #include "quaternion.h"
 #include "pid.h"
-#include "lpf.h"
+#include "filter.h"
 #include "util.h"
 
 #define PITCHRATE_P 0.05

flix/estimate.ino

@@ -5,7 +5,7 @@
 
 #include "quaternion.h"
 #include "vector.h"
-#include "lpf.h"
+#include "filter.h"
 #include "util.h"
 
 Vector rates; // estimated angular rates, rad/s
@@ -15,6 +15,12 @@ bool landed;
 float accWeight = 0.003;
 float levelWeight = 0.0002;
 LowPassFilter<Vector> ratesFilter(0.2); // cutoff frequency ~ 40 Hz
+NotchFilter<Vector> ratesNotch(382, 0);
+
+void setupEstimate() {
+	print("Setup estimation\n");
+	ratesNotch.reset();
+}
 
 void estimate() {
 	applyGyro();
@@ -25,6 +31,7 @@ void estimate() {
 void applyGyro() {
 	// filter gyro to get angular rates
 	rates = ratesFilter.update(gyro);
+	rates = ratesNotch.update(rates);
 
 	// apply rates to attitude
 	attitude = Quaternion::rotate(attitude, Quaternion::fromRotationVector(rates * dt));

flix/filter.h

@@ -0,0 +1,98 @@
+// Copyright (c) 2023 Oleg Kalachev <okalachev@gmail.com>
+// Repository: https://github.com/okalachev/flix
+
+// Low pass and notch filters
+
+#pragma once
+
+template <typename T> // Using template to make the filter usable for scalar and vector values
+class LowPassFilter {
+public:
+	float alpha; // smoothing constant, 1 means filter disabled
+	T output;
+
+	LowPassFilter(float alpha): alpha(alpha) {};
+
+	T update(const T input) {
+		if (!init) {
+			init = true;
+			return output = input;
+		}
+		return output += alpha * (input - output);
+	}
+
+	void setCutOffFrequency(float cutOffFreq, float dt) {
+		alpha = 1 - exp(-2 * PI * cutOffFreq * dt);
+	}
+
+	void reset() {
+		init = false;
+	}
+
+private:
+	bool init = false;
+};
+
+template <typename T>
+class NotchFilter {
+public:
+	float frequency;
+	float bandwidth;
+	T output;
+
+	NotchFilter(float frequency, float bandwidth): frequency(frequency), bandwidth(bandwidth) {
+		reset();
+	};
+
+	T update(const T input) {
+		if (frequency <= 0 || bandwidth <= 0) return input;
+
+		if (!init) {
+			init = true;
+			x1 = x2 = input;
+			y1 = y2 = input;
+			return output = input;
+		}
+
+		output = b0 * input + b1 * x1 + b2 * x2 - a1 * y1 - a2 * y2;
+
+		x2 = x1;
+		x1 = input;
+		y2 = y1;
+		y1 = output;
+
+		return output;
+	}
+
+	void reset() {
+		const float dt = 0.001f;
+		float f = frequency;
+		float bw = bandwidth;
+		if (f < 0) f = 0;
+		if (bw < 1e-6f) bw = 1e-6f;
+
+		float q = f / bw;
+		if (q < 1e-3f) q = 1e-3f;
+
+		const float w0 = 2.0f * PI * f * dt;
+		const float c = cos(w0);
+		const float s = sin(w0);
+		const float alpha = s / (2.0f * q);
+
+		const float a0 = 1.0f + alpha;
+		const float invA0 = 1.0f / a0;
+
+		b0 = 1.0f * invA0;
+		b1 = -2.0f * c * invA0;
+		b2 = 1.0f * invA0;
+		a1 = -2.0f * c * invA0;
+		a2 = (1.0f - alpha) * invA0;
+
+		init = false;
+	}
+
+private:
+	float b0, b1, b2, a1, a2;
+	T x1, x2, y1, y2;
+	bool init = false;
+};

flix/flix.ino

@@ -26,6 +26,8 @@ void setup() {
 	setupWiFi();
 	setupIMU();
 	setupRC();
+	setupEstimate();
+	setupLog();
 	setLED(false);
 	print("Initializing complete\n");
 }
@@ -40,6 +42,6 @@ void loop() {
 	handleInput();
 	processMavlink();
 	readVoltage();
-	logData();
+	loopLog();
 	syncParameters();
 }

flix/imu.ino

@@ -6,7 +6,7 @@
 #include <SPI.h>
 #include <FlixPeriph.h>
 #include "vector.h"
-#include "lpf.h"
+#include "filter.h"
 #include "util.h"
 
 MPU9250 imu(SPI);

flix/log.ino

@@ -1,77 +1,272 @@
 // Copyright (c) 2023 Oleg Kalachev <okalachev@gmail.com>
 // Repository: https://github.com/okalachev/flix
 
-// In-RAM logging
+// Logging subsystem
 
 #include "vector.h"
 #include "util.h"
 
-#define LOG_RATE 100
+int logMemory = -1; // 0 - RAM, 1 - PSRAM, -1 - disabled
-#define LOG_DURATION 10
+float logUsage = 0.5; // fraction of free memory to use for log
-#define LOG_SIZE LOG_DURATION * LOG_RATE
 
-Vector attitudeEuler;
+struct LogValue {
-Vector attitudeTargetEuler;
-
-struct LogEntry {
 	const char *name;
-	float *value;
+	Value value;
+	float lastValue = NAN;
+	bool logged = true; // if false, use only for triggering log update
+	LogValue() : name(nullptr), value() {}; // empty value constructor
+	template <typename T>
+	LogValue(const char *name, T value, bool logged = true) : name(name), value(value), logged(logged) {};
 };
 
-LogEntry logEntries[] = {
+struct LogTopic {
-	{"t", &t},
+	LogValue values[10];
-	{"rates.x", &rates.x},
+	int length = 0; // number of logged values
-	{"rates.y", &rates.y},
+	float throttle; // max update rate, Hz
-	{"rates.z", &rates.z},
+	float lastUpdate = -INFINITY;
-	{"ratesTarget.x", &ratesTarget.x},
+
-	{"ratesTarget.y", &ratesTarget.y},
+	LogTopic(float throttle, LogValue v0, LogValue v1 = {}, LogValue v2 = {}, LogValue v3 = {}, LogValue v4 = {}, LogValue v5 = {}, LogValue v6 = {}, LogValue v7 = {}, LogValue v8 = {}, LogValue v9 = {}) :
-	{"ratesTarget.z", &ratesTarget.z},
+		throttle(throttle), values{v0, v1, v2, v3, v4, v5, v6, v7, v8, v9} {
-	{"attitude.x", &attitudeEuler.x},
+			// Count logged values
-	{"attitude.y", &attitudeEuler.y},
+			for (auto& v : values) {
-	{"attitude.z", &attitudeEuler.z},
+				if (v.name == nullptr) break;
-	{"attitudeTarget.x", &attitudeTargetEuler.x},
+				if (v.logged) length++;
-	{"attitudeTarget.y", &attitudeTargetEuler.y},
+			}
-	{"attitudeTarget.z", &attitudeTargetEuler.z},
+		};
-	{"thrustTarget", &thrustTarget}
+
+	LogTopic(LogValue v0, LogValue v1 = {}, LogValue v2 = {}, LogValue v3 = {}, LogValue v4 = {}, LogValue v5 = {}, LogValue v6 = {}, LogValue v7 = {}, LogValue v8 = {}, LogValue v9 = {}) :
+		LogTopic(INFINITY, v0, v1, v2, v3, v4, v5, v6, v7, v8, v9) {};
 };
 
-const int logColumns = sizeof(logEntries) / sizeof(logEntries[0]);
+LogTopic logTopics[] = {
-float logBuffer[LOG_SIZE][logColumns];
+	// time
+	LogTopic({"t", &t}), // must be the first topic
+	LogTopic(1, {"loopRate", &loopRate}),
 
-void prepareLogData() {
+	// imu
-	attitudeEuler = attitude.toEuler();
+	LogTopic(
-	attitudeTargetEuler = attitudeTarget.toEuler();
+		{"gyro.x", &gyro.x},
-}
+		{"gyro.y", &gyro.y},
+		{"gyro.z", &gyro.z}),
 
-void logData() {
+	LogTopic(50,
-	if (!armed) return;
+		{"acc.x", &acc.x},
-	static int logPointer = 0;
+		{"acc.y", &acc.y},
-	static Rate period(LOG_RATE);
+		{"acc.z", &acc.z}),
-	if (!period) return;
 
-	prepareLogData();
+	LogTopic(10,
+		{"gyroBias.x", &gyroBias.x},
+		{"gyroBias.y", &gyroBias.y},
+		{"gyroBias.z", &gyroBias.z}),
 
-	for (int i = 0; i < logColumns; i++) {
+	// estimation
-		logBuffer[logPointer][i] = *logEntries[i].value;
+	LogTopic(50,
-	}
+		{"rates.x", &rates.x},
+		{"rates.y", &rates.y},
+		{"rates.z", &rates.z},
+		{"attitude.roll", []() { return attitude.getRoll(); }},
+		{"attitude.pitch", []() { return attitude.getPitch(); }},
+		{"attitude.yaw", []() { return attitude.getYaw(); }}),
 
-	logPointer++;
+	// rc
-	if (logPointer >= LOG_SIZE) {
+	LogTopic(10,
-		logPointer = 0;
+		{"controlTime", &controlTime, false}, // trigger value
+		{"controlRoll", &controlRoll},
+		{"controlPitch", &controlPitch},
+		{"controlYaw", &controlYaw},
+		{"controlThrottle", &controlThrottle}),
+
+	// control
+	LogTopic({"armed", &armed}),
+	LogTopic({"mode", &mode}),
+
+	LogTopic(10,
+		{"ratesTarget.x", &ratesTarget.x},
+		{"ratesTarget.y", &ratesTarget.y},
+		{"ratesTarget.z", &ratesTarget.z},
+		{"attitudeTarget.roll", []() { return attitudeTarget.getRoll(); }},
+		{"attitudeTarget.pitch", []() { return attitudeTarget.getPitch(); }},
+		{"attitudeTarget.yaw", []() { return attitudeTarget.getYaw(); }},
+		{"thrustTarget", &thrustTarget}),
+
+	// motors
+	LogTopic(
+		{"motors[0]", &motors[0]},
+		{"motors[1]", &motors[1]},
+		{"motors[2]", &motors[2]},
+		{"motors[3]", &motors[3]}),
+
+	// misc
+	LogTopic(5,
+		{"voltage", &voltage},
+		{"temp", &temperatureRead},
+		{"imuTemp", []() { return imu.getTemp(); }}),
+};
+
+void *logBuffer; // buffer for log data
+size_t logCapacity;
+size_t logCursor = 0;
+size_t logLength = 0;
+LogValue *logExposed = nullptr; // log values exposed to telemetry
+
+void setupLog() {
+	print("Setup log\n");
+
+	free(logBuffer); // when reconfiguring
+	logBuffer = nullptr;
+	logCursor = 0;
+	logLength = 0;
+
+	if (logMemory == 0) {
+		logCapacity = ESP.getFreeHeap() * logUsage;
+		logBuffer = (uint8_t *)calloc(logCapacity, 1);
+	} else if (logMemory == 1) {
+		logCapacity = ESP.getFreePsram() * logUsage;
+		logBuffer = (uint8_t *)heap_caps_calloc(logCapacity, 1, MALLOC_CAP_SPIRAM | MALLOC_CAP_8BIT);
 	}
 }
 
-void printLogHeader() {
+void loopLog() {
-	for (int i = 0; i < logColumns; i++) {
+	if (logBuffer == nullptr || !armed) return;
-		print("%s%s", logEntries[i].name, i < logColumns - 1 ? "," : "\n");
-	}
-}
 
-void printLogData() {
+	if (!logLength) resetLog(); // reset state on first log write
-	for (int i = 0; i < LOG_SIZE; i++) {
+
-		if (logBuffer[i][0] == 0) continue; // skip empty records
+	static Rate sync(2);
-		for (int j = 0; j < logColumns; j++) {
+	if (sync) {
-			print("%g%s", logBuffer[i][j], j < logColumns - 1 ? "," : "\n");
+		const uint8_t marker[] = {0x1A, 0x91, 0x4F, 0xF6, 0x7F};
+		writeLog(&marker, sizeof(marker)); // write sync marker
+	}
+
+	for (uint8_t i = 0; i < sizeof(logTopics) / sizeof(logTopics[0]); i++) {
+		LogTopic& topic = logTopics[i];
+		if (t - topic.lastUpdate < 1 / topic.throttle) continue; // throttle topic
+		if (!isTopicUpdated(i)) continue; // skip if topic was't updated
+
+		topic.lastUpdate = t;
+		writeLog(&i, sizeof(i)); // write topic index
+
+		for (auto& value : topic.values) {
+			if (value.name == nullptr) break;
+			if (!value.logged) continue;
+			value.lastValue = value.value.get();
+			writeLog(&value.lastValue, sizeof(float)); // write value
 		}
 	}
 }
+
+void resetLog() {
+	for (auto& topic : logTopics) {
+		topic.lastUpdate = -INFINITY;
+		for (auto& value : topic.values) {
+			value.lastValue = NAN;
+		}
+	}
+	logCursor = 0;
+	logLength = 0;
+}
+
+void writeLog(const void *data, size_t size) {
+	size_t first = min(size, logCapacity - logCursor);
+	size_t second = size - first;
+	memcpy(logBuffer + logCursor, data, first);
+	logCursor = (logCursor + first) % logCapacity;
+	if (second > 0) {
+		memcpy(logBuffer + logCursor, data + first, second);
+		logCursor = (logCursor + second) % logCapacity;
+	}
+	logLength = min(logLength + size, logCapacity);
+}
+
+void readLog(void *data, size_t position, size_t size) {
+	if (logLength == logCapacity) {
+		position = (logCursor + position) % logCapacity;
+	}
+	size_t first = min(size, logCapacity - position);
+	size_t second = size - first;
+	memcpy(data, logBuffer + position, first);
+	if (second > 0) {
+		memcpy(data + first, logBuffer, second);
+	}
+}
+
+bool isTopicUpdated(const uint8_t topic) {
+	LogTopic& logTopic = logTopics[topic];
+	bool updated = false;
+
+	for (auto& value : logTopic.values) {
+		if (value.name == nullptr) break;
+		float v = value.value.get();
+		if (!floatEquals(value.lastValue, v)) {
+			value.lastValue = v;
+			updated = true;
+		}
+	}
+	return updated;
+}
+
+void printLogInfo() {
+	if (logMemory == -1) return print("Log: disabled\n");
+
+	print("Memory: %s\n", logMemory == 0 ? "RAM" : "PSRAM");
+	print("Usage: %.f%%\n", logUsage * 100);
+	print("Capacity: %u bytes\n", (unsigned)logCapacity);
+	print("Used: %u bytes\n", (unsigned)logLength);
+	print("Estimated duration: %d seconds\n", estimateLogDuration());
+}
+
+int estimateLogDuration() {
+	float bandwidth = 0;
+	for (LogTopic& topic : logTopics) {
+		float rate = isinf(topic.throttle) ? loopRate : topic.throttle;
+		bandwidth += rate * topic.length * sizeof(float);
+	}
+	return logCapacity / bandwidth;
+}
+
+void printLogHeader() {
+	int i = 0;
+	for (auto& topic : logTopics) {
+		print("Topic #%d (%g Hz):\n", i++, topic.throttle);
+		for (auto& value : topic.values) {
+			if (value.name == nullptr) break;
+			print("  %s%s\n", value.name, value.logged ?"" : " (not logged)");
+		}
+	}
+}
+
+void printLogValues(const char *filter) {
+	for (LogTopic& topic : logTopics) {
+		for (LogValue& value : topic.values) {
+			if (value.name == nullptr) break;
+			if (strncasecmp(value.name, filter, strlen(filter))) continue;
+			print("%s = %g\n", value.name, value.value.get());
+		}
+	}
+}
+
+void configLogThrottle(const char *name, float throttle) {
+	for (LogTopic& topic : logTopics) {
+		for (LogValue& value : topic.values) {
+			if (value.name == nullptr) break;
+			if (strcasecmp(value.name, name) != 0) continue;
+			topic.throttle = throttle;
+			print("Log throttle for %s set to %.1f Hz\n", name, throttle);
+			return;
+		}
+	}
+	print("Log value not found: %s\n", name);
+}
+
+void exposeLogValue(const char *name) {
+	for (int i = 0; i < sizeof(logTopics) / sizeof(logTopics[0]); i++) {
+		LogTopic& topic = logTopics[i];
+		for (LogValue& value : topic.values) {
+			if (value.name == nullptr) break;
+			if (strcasecmp(value.name, name) != 0) continue;
+			logExposed = &value;
+			print("Log value %s exposed\n", name);
+			return;
+		}
+	}
+	print("Log value not found: %s\n", name);
+}

flix/lpf.h

@@ -1,34 +0,0 @@
-// Copyright (c) 2023 Oleg Kalachev <okalachev@gmail.com>
-// Repository: https://github.com/okalachev/flix
-
-// Low pass filter implementation
-
-#pragma once
-
-template <typename T> // Using template to make the filter usable for scalar and vector values
-class LowPassFilter {
-public:
-	float alpha; // smoothing constant, 1 means filter disabled
-	T output;
-
-	LowPassFilter(float alpha): alpha(alpha) {};
-
-	T update(const T input) {
-		if (!init) {
-			init = true;
-			return output = input;
-		}
-		return output += alpha * (input - output);
-	}
-
-	void setCutOffFrequency(float cutOffFreq, float dt) {
-		alpha = 1 - exp(-2 * PI * cutOffFreq * dt);
-	}
-
-	void reset() {
-		init = false;
-	}
-
-private:
-	bool init = false;
-};

flix/mavlink.ino

@@ -16,6 +16,7 @@ Rate telemetryAttitude(20);
 Rate telemetryRC(10);
 Rate telemetryMotors(10);
 Rate telemetryIMU(15);
+Rate telemetryTopic(10);
 
 bool mavlinkConnected = false;
 String mavlinkPrintBuffer;
@@ -84,6 +85,12 @@ void sendMavlink() {
 			0, 0, 0, 0);
 		sendMessage(&msg);
 	}
+
+	if (telemetryTopic && logExposed != nullptr) {
+		mavlink_msg_named_value_float_pack(mavlinkSysId, MAV_COMP_ID_AUTOPILOT1, &msg,
+			time, logExposed->name, logExposed->value.get());
+		sendMessage(&msg);
+	}
 }
 
 void sendMessage(const void *msg) {
@@ -92,6 +99,26 @@ void sendMessage(const void *msg) {
 	sendWiFi(buf, len);
 }
 
+static uint8_t mavlinkBatch[ESP_NOW_MAX_DATA_LEN_V2];
+static int mavlinkBatchSize = 0;
+
+void batchMessage(const void *msg) {
+	uint8_t buf[MAVLINK_MAX_PACKET_LEN];
+	int len = mavlink_msg_to_send_buffer(buf, (mavlink_message_t *)msg);
+
+	if (mavlinkBatchSize + len > sizeof(mavlinkBatch)) {
+		sendWiFi(mavlinkBatch, mavlinkBatchSize);
+		mavlinkBatchSize = 0;
+	}
+	memcpy(mavlinkBatch + mavlinkBatchSize, buf, len);
+	mavlinkBatchSize += len;
+}
+
+void flushBatchMessages() {
+	sendWiFi(mavlinkBatch, mavlinkBatchSize);
+	mavlinkBatchSize = 0;
+}
+
 void receiveMavlink() {
 	uint8_t buf[MAVLINK_MAX_PACKET_LEN];
 	int len = receiveWiFi(buf, MAVLINK_MAX_PACKET_LEN);
@@ -196,18 +223,24 @@ void handleMavlink(const void *_msg) {
 		mavlink_msg_set_attitude_target_decode(&msg, &m);
 		if (m.target_system && m.target_system != mavlinkSysId) return;
 
-		// copy attitude, rates and thrust targets
+		if (!(m.type_mask & ATTITUDE_TARGET_TYPEMASK_ATTITUDE_IGNORE)) {
-		ratesTarget.x = m.body_roll_rate;
+			// Attitude control
-		ratesTarget.y = -m.body_pitch_rate; // convert to flu
+			attitudeTarget.w = m.q[0];
-		ratesTarget.z = -m.body_yaw_rate;
+			attitudeTarget.x = m.q[1];
-		attitudeTarget.w = m.q[0];
+			attitudeTarget.y = -m.q[2];
-		attitudeTarget.x = m.q[1];
+			attitudeTarget.z = -m.q[3];
-		attitudeTarget.y = -m.q[2];
+			ratesExtra.x = m.type_mask & ATTITUDE_TARGET_TYPEMASK_BODY_ROLL_RATE_IGNORE ? 0 : m.body_roll_rate;
-		attitudeTarget.z = -m.q[3];
+			ratesExtra.y = m.type_mask & ATTITUDE_TARGET_TYPEMASK_BODY_PITCH_RATE_IGNORE ? 0 : -m.body_pitch_rate; // convert to flu
-		thrustTarget = m.thrust;
+			ratesExtra.z = m.type_mask & ATTITUDE_TARGET_TYPEMASK_BODY_YAW_RATE_IGNORE ? 0 : -m.body_yaw_rate;
-		ratesExtra = Vector(0, 0, 0);
+		} else {
+			// Rates control
+			attitudeTarget.invalidate();
+			ratesTarget.x = m.type_mask & ATTITUDE_TARGET_TYPEMASK_BODY_ROLL_RATE_IGNORE ? ratesTarget.x : m.body_roll_rate;
+			ratesTarget.y = m.type_mask & ATTITUDE_TARGET_TYPEMASK_BODY_PITCH_RATE_IGNORE ? ratesTarget.y : -m.body_pitch_rate;
+			ratesTarget.z = m.type_mask & ATTITUDE_TARGET_TYPEMASK_BODY_YAW_RATE_IGNORE ? ratesTarget.z : -m.body_yaw_rate;
+		}
 
-		if (m.type_mask & ATTITUDE_TARGET_TYPEMASK_ATTITUDE_IGNORE) attitudeTarget.invalidate();
+		thrustTarget = valid(m.thrust) ? m.thrust : thrustTarget;
 		armed = m.thrust > 0;
 	}
 
@@ -225,18 +258,29 @@ void handleMavlink(const void *_msg) {
 		armed = motors[0] > 0 || motors[1] > 0 || motors[2] > 0 || motors[3] > 0;
 	}
 
+	if (msg.msgid == MAVLINK_MSG_ID_LOG_REQUEST_LIST) {
+		const uint32_t qgcEpoch = 1262304000; // qgc accepts only timestamps after 2010-01-01
+		mavlink_message_t response;
+		mavlink_msg_log_entry_pack(mavlinkSysId, MAV_COMP_ID_AUTOPILOT1, &response,
+			0, 1, 0, qgcEpoch + t * 60, logLength); // put fake unique date to make qgc happy with saving logs
+		sendMessage(&response);
+	}
+
 	if (msg.msgid == MAVLINK_MSG_ID_LOG_REQUEST_DATA) {
 		mavlink_log_request_data_t m;
 		mavlink_msg_log_request_data_decode(&msg, &m);
 		if (m.target_system && m.target_system != mavlinkSysId) return;
 
-		// Send all log records
+		for (int i = 0; i < m.count; i += MAVLINK_MSG_LOG_DATA_FIELD_DATA_LEN) {
-		for (int i = 0; i < sizeof(logBuffer) / sizeof(logBuffer[0]); i++) {
+			int chunkSize = min(MAVLINK_MSG_LOG_DATA_FIELD_DATA_LEN, (int)(m.count - i));
-			mavlink_message_t msg;
+			mavlink_message_t response;
-			mavlink_msg_log_data_pack(mavlinkSysId, MAV_COMP_ID_AUTOPILOT1, &msg, 0, i,
+			uint8_t data[MAVLINK_MSG_LOG_DATA_FIELD_DATA_LEN];
-				sizeof(logBuffer[0]), (uint8_t *)logBuffer[i]);
+			readLog(data, m.ofs + i, chunkSize);
-			sendMessage(&msg);
+			mavlink_msg_log_data_pack(mavlinkSysId, MAV_COMP_ID_AUTOPILOT1, &response,
+				m.id, m.ofs + i, chunkSize, data);
+			batchMessage(&response);
 		}
+		flushBatchMessages();
 	}
 
 	// Handle commands

flix/motors.ino

@@ -7,7 +7,7 @@
 
 float motors[4]; // normalized motor thrusts in range [0..1]
 
-int motorPins[4] = {12, 13, 14, 15}; // default pin numbers
+int motorPins[4] = {-1, -1, -1, -1}; // default pin numbers
 int pwmFrequency = 78000;
 int pwmResolution = 10;
 int pwmStop = 0;

flix/parameters.ino

@@ -10,7 +10,7 @@ extern int channelZero[16], channelMax[16];
 extern int rollChannel, pitchChannel, throttleChannel, yawChannel, armedChannel, modeChannel;
 extern int rcRxPin, voltagePin;
 extern int wifiMode, wifiLongRange, udpLocalPort, udpRemotePort, espnowChannel;
-extern float rcLossTimeout, descendTime;
+extern float rcLossTimeout, descendTime, disarmTilt;
 extern float voltageScale;
 extern LowPassFilter<float> voltageFilter;
 
@@ -74,6 +74,8 @@ Parameter parameters[] = {
 	{"EST_ACC_WEIGHT", &accWeight},
 	{"EST_LVL_WEIGHT", &levelWeight},
 	{"EST_RATES_LPF_A", &ratesFilter.alpha},
+	{"EST_RATES_NF_F", &ratesNotch.frequency, setupEstimate},
+	{"EST_RATES_NF_BW", &ratesNotch.bandwidth, setupEstimate},
 	// motors
 	{"MOT_PIN_FL", &motorPins[MOTOR_FRONT_LEFT], setupMotors},
 	{"MOT_PIN_FR", &motorPins[MOTOR_FRONT_RIGHT], setupMotors},
@@ -121,6 +123,22 @@ Parameter parameters[] = {
 	{"MAV_RATE_RC", &telemetryRC.rate},
 	{"MAV_RATE_MOT", &telemetryMotors.rate},
 	{"MAV_RATE_IMU", &telemetryIMU.rate},
+	{"MAV_RATE_TOPIC", &telemetryTopic.rate},
+	// log
+	{"LOG_MEMORY", &logMemory, setupLog},
+	{"LOG_USAGE", &logUsage, setupLog},
+	{"LOG_RATE_000", &logTopics[0].throttle},
+	{"LOG_RATE_001", &logTopics[1].throttle},
+	{"LOG_RATE_002", &logTopics[2].throttle},
+	{"LOG_RATE_003", &logTopics[3].throttle},
+	{"LOG_RATE_004", &logTopics[4].throttle},
+	{"LOG_RATE_005", &logTopics[5].throttle},
+	{"LOG_RATE_006", &logTopics[6].throttle},
+	{"LOG_RATE_007", &logTopics[7].throttle},
+	{"LOG_RATE_008", &logTopics[8].throttle},
+	{"LOG_RATE_009", &logTopics[9].throttle},
+	{"LOG_RATE_010", &logTopics[10].throttle},
+	{"LOG_RATE_011", &logTopics[11].throttle},
 	// power
 	{"PWR_VOLT_PIN", &voltagePin, setupPower},
 	{"PWR_VOLT_SCALE", &voltageScale},
@@ -128,6 +146,7 @@ Parameter parameters[] = {
 	// safety
 	{"SF_RC_LOSS_TIME", &rcLossTimeout},
 	{"SF_DESCEND_TIME", &descendTime},
+	{"SF_DISARM_TILT", &disarmTilt}
 };
 
 void setupParameters() {

flix/pid.h

@@ -5,7 +5,7 @@
 
 #pragma once
 
-#include "lpf.h"
+#include "filter.h"
 
 class PID {
 public:

flix/power.ino

@@ -5,11 +5,11 @@
 
 #include <soc/soc.h>
 #include <soc/rtc_cntl_reg.h>
-#include "lpf.h"
+#include "filter.h"
 #include "util.h"
 
 float voltage = NAN;
-LowPassFilter<float> voltageFilter(0.2);
+LowPassFilter<float> voltageFilter(1);
 int voltagePin = -1;
 float voltageScale = 2;
 

flix/safety.ino

@@ -8,10 +8,12 @@ extern float controlRoll, controlPitch, controlThrottle, controlYaw;
 
 float rcLossTimeout = 1;
 float descendTime = 10;
+float disarmTilt = radians(120);
 
 void failsafe() {
 	rcLossFailsafe();
 	autoFailsafe();
+	tiltFailsafe();
 }
 
 // RC loss failsafe
@@ -45,3 +47,15 @@ void autoFailsafe() {
 	yaw = controlYaw;
 	throttle = controlThrottle;
 }
+
+// Disarm if tilted too much
+void tiltFailsafe() {
+	if (!armed) return;
+	if (mode != STAB) return;
+
+	Vector up = Quaternion::rotateVector(Vector(0, 0, 1), attitude);
+	float tilt = acos(up.z);
+	if (disarmTilt && tilt > disarmTilt) {
+		armed = false;
+	}
+}

flix/util.h

@@ -64,6 +64,49 @@ public:
 	}
 };
 
+// Simple variant type for logging and parameters
+struct Value {
+	enum { EMPTY, FLOAT, INT, BOOL, FLOAT_FN, INT_FN, BOOL_FN } type;
+	union {
+		void *pointer;
+		float *_float;
+		int *_int;
+		bool *_bool;
+		float (*floatFn)();
+		int (*intFn)();
+		bool (*boolFn)();
+	};
+
+	Value() : type(EMPTY), pointer(nullptr) {};
+	Value(float *pt) : type(FLOAT), _float(pt) {};
+	Value(int *pt) : type(INT), _int(pt) {};
+	Value(bool *pt) : type(BOOL), _bool(pt) {};
+	Value(float (*fn)()) : type(FLOAT_FN), floatFn(fn) {};
+	Value(int (*fn)()) : type(INT_FN), intFn(fn) {};
+	Value(bool (*fn)()) : type(BOOL_FN), boolFn(fn) {};
+
+	float get() const {
+		switch (type) {
+			case FLOAT: return *_float;
+			case INT: return *_int;
+			case BOOL: return *_bool ? 1 : 0;
+			case FLOAT_FN: return floatFn();
+			case INT_FN: return intFn();
+			case BOOL_FN: return boolFn() ? 1 : 0;
+			default: return NAN;
+		}
+	};
+
+	void set(float value) const {
+		switch (type) {
+			case FLOAT: *_float = value; break;
+			case INT: *_int = value; break;
+			case BOOL: *_bool = (value != 0); break;
+			default: break;
+		}
+	};
+};
+
 // Rate limiter
 class Rate {
 public:

flix/wifi.ino

@@ -89,7 +89,7 @@ void printWiFiInfo() {
 		print("MAC: %s\n", WiFi.softAPmacAddress().c_str());
 		print("Peer MAC: %s\n", MacAddress(espnow.addr()).toString().c_str());
 		print("Encrypted: %d\n", espnow.isEncrypted());
-		print("Channel: %d\n", espnow.getChannel());
+		print("Channel: %d\n", WiFi.channel());
 		print("Lost packets: %d\n", espnow.lost);
 	} else if (WiFi.getMode() == WIFI_MODE_AP) {
 		print("Mode: Access Point (AP)\n");

gazebo/Arduino.h

@@ -20,6 +20,10 @@
 #define radians(deg) ((deg)*DEG_TO_RAD)
 #define degrees(rad) ((rad)*RAD_TO_DEG)
 
+#define MALLOC_CAP_SPIRAM (1<<10)
+#define MALLOC_CAP_8BIT (1<<2)
+#define ESP_NOW_MAX_DATA_LEN_V2 1470
+
 #define constrain(amt,low,high) ((amt)<(low)?(low):((amt)>(high)?(high):(amt)))
 template<typename T> T max(T a, T b) { return a > b ? a : b; }
 template<typename T> T min(T a, T b) { return a < b ? a : b; }
@@ -156,6 +160,8 @@ HardwareSerial Serial, Serial1, Serial2;
 class EspClass {
 public:
 	void restart() { Serial.println("Ignore reboot in simulation"); }
+	uint32_t getFreeHeap() { return 300 * 1024; } // assume 300 KB free heap
+	uint32_t getFreePsram() { return 8 * 1024 * 1024; } // assume 8 MB free PSRAM
 } ESP;
 
 unsigned long __delayTime = 0;
@@ -165,11 +171,16 @@ void delay(uint32_t ms) {
 	__delayTime += ms * 1000;
 }
 
+void *heap_caps_calloc(size_t n, size_t size, uint32_t caps) {
+	return calloc(n, size);
+}
+
 bool ledcAttach(uint8_t pin, uint32_t freq, uint8_t resolution) { return true; }
 bool ledcWrite(uint8_t pin, uint32_t duty) { return true; }
 uint32_t ledcChangeFrequency(uint8_t pin, uint32_t freq, uint8_t resolution) { return freq; }
 int8_t digitalPinToAnalogChannel(uint8_t pin) { return -1; }
 uint32_t analogReadMilliVolts(uint8_t pin) { return 0; }
+float temperatureRead() { return 0; }
 
 unsigned long __micros;
 unsigned long __resetTime = 0;

gazebo/flix.h

@@ -9,7 +9,7 @@
 #include "quaternion.h"
 #include "Arduino.h"
 #include "wifi.h"
-#include "lpf.h"
+#include "filter.h"
 
 extern float t, dt;
 extern float controlRoll, controlPitch, controlYaw, controlThrottle, controlMode;
@@ -48,8 +48,17 @@ void normalizeRC();
 void calibrateRC();
 void calibrateRCChannel(int*, uint16_t[16], uint16_t[16], const char*);
 void printRCCalibration();
+void loopLog();
+void resetLog();
+void writeLog(const void *data, size_t size);
+void readLog(void *data, size_t position, size_t size);
+bool isTopicUpdated(const uint8_t topic);
+void printLogInfo();
+int estimateLogDuration();
 void printLogHeader();
-void printLogData();
+void printLogValues(const char *filter);
+void configLogThrottle(const char *name, float throttle);
+void exposeLogValue(const char *name);
 void processMavlink();
 void sendMavlink();
 void sendMessage(const void *msg);
@@ -63,6 +72,7 @@ void failsafe();
 void rcLossFailsafe();
 void descend();
 void autoFailsafe();
+void tiltFailsafe();
 int parametersCount();
 const char *getParameterName(int index);
 float getParameter(int index);
@@ -79,3 +89,8 @@ void printIMUInfo() {};
 void printWiFiInfo() {};
 void configWiFi(bool, const char*, const char*) { print("Skip WiFi config\n"); };
 void setWiFiMode(const String& mode) { print("Skip WiFi mode set\n"); };
+
+class IMU {
+public:
+	float getTemp() { return 0; }
+} imu;

gazebo/simulator.cpp

@@ -23,7 +23,7 @@
 #include "estimate.ino"
 #include "safety.ino"
 #include "log.ino"
-#include "lpf.h"
+#include "filter.h"
 #include "mavlink.ino"
 #include "motors.ino"
 #include "parameters.ino"
@@ -55,6 +55,7 @@ public:
 		initNode();
 		Serial.begin(0);
 		setupParameters();
+		setupLog();
 		rcRxPin = 1; // set rc pin to enable rc reading
 		gzmsg << "Flix plugin loaded" << endl;
 	}
@@ -88,7 +89,7 @@ public:
 
 		applyMotorForces();
 		publishTopics();
-		logData();
+		loopLog();
 		syncParameters();
 	}
 

tools/csv_to_mcap.py

@@ -9,6 +9,7 @@ Usage:
 import csv
 import json
 import docopt
+import math
 from mcap.writer import Writer
 
 args = docopt.docopt(__doc__)
@@ -39,7 +40,15 @@ channel_id = writer.register_channel(
 )
 
 for row in csv_reader:
-    data = {key: float(value) for key, value in zip(header, row)}
+    if row[0] == '': continue
+    data = {}
+    for key, value in zip(header, row):
+        if value == '' or math.isnan(float(value)):
+            data[key] = None
+        else:
+            data[key] = float(value)
+
+    data = {key: float(value) if value != '' else None for key, value in zip(header, row)}
     timestamp = round(float(row[0]) * 1e9)
     writer.add_message(channel_id=channel_id, log_time=timestamp, data=json.dumps(data).encode(), publish_time=timestamp,)
 

tools/espnow-proxy/espnow-proxy.ino

@@ -11,18 +11,22 @@
 #include <Preferences.h>
 #include "../../flix/util.h"
 
-const int CHANNEL = 6;
+const bool DISABLE_SWARM = true;
+const int CHANNEL = -1; // -1 means auto search
 char key[ESP_NOW_KEY_LEN + 1] = {0}; // with trailing null
 
 Preferences storage;
 
 std::vector<ESPNOWSerial *> peers;
+bool stop = false;
 
 void onNewPeer(const esp_now_recv_info_t *info, const uint8_t *data, int len, void *arg) {
 	if (len != 4 || memcmp(data, "flix", 4) != 0) return; // check if discovery message
 
+	if (stop) return;
+
 	Serial.printf("New peer: " MACSTR "\n", MAC2STR(info->src_addr));
-	ESPNOWSerial *link = new ESPNOWSerial(info->src_addr, CHANNEL, WIFI_IF_AP);
+	ESPNOWSerial *link = new ESPNOWSerial(info->src_addr, WiFi.channel(), WIFI_IF_STA);
 	link->begin();
 	link->setKey((const uint8_t *)key);
 	peers.push_back(link);
@@ -30,9 +34,8 @@ void onNewPeer(const esp_now_recv_info_t *info, const uint8_t *data, int len, vo
 
 void setup() {
 	Serial.begin(115200);
-	WiFi.mode(WIFI_AP);
+	WiFi.mode(WIFI_STA);
 	WiFi.setSleep(false);
-	WiFi.setChannel(CHANNEL);
 
 	ESP_NOW.onNewPeer(onNewPeer, NULL);
 	ESP_NOW.begin();
@@ -43,12 +46,6 @@ void setup() {
 		storage.putString("key", key);
 	}
 	strcpy(key, storage.getString("key").c_str());
-
-	// Discover the first peer
-	while (peers.empty()) {
-		Serial.printf("espnow %s %s\n", WiFi.softAPmacAddress().c_str(), key);
-		delay(500);
-	}
 }
 
 void generateRandomKey() {
@@ -61,6 +58,20 @@ void generateRandomKey() {
 void loop() {
 	uint8_t buf[5000];
 
+	static int channelIndex = 0;
+	static const int channels[] = {6, 11, 1, 2, 6, 11, 3, 4, 5, 6, 1, 11, 8, 6, 9, 10, 11, 6, 1, 12, 13}; // 6, 1 and 11 are most common
+
+	static unsigned long last = 0;
+	if (!stop && millis() - last > 500) {
+		// Change search channel
+		last = millis();
+		channelIndex = (channelIndex + 1) % (sizeof(channels) / sizeof(channels[0]));
+		int channel = CHANNEL < 0 ? channels[channelIndex] : CHANNEL;
+		Serial.printf("Run on Flix: espnow %s %s\n", WiFi.STA.macAddress().c_str(), key);
+		Serial.printf("Searching channel %d\n", channel);
+		WiFi.setChannel(channel);
+	}
+
 	// Send from Serial to ESP-NOW
 	while (Serial.available() > 0) {
 		int b = Serial.read();
@@ -81,6 +92,15 @@ void loop() {
 	// Send from ESP-NOW to Serial
 	for (ESPNOWSerial *link : peers) {
 		int len = link->read(buf, sizeof(buf));
+		if (!stop) {
+			for (int i = 0; i < len; i++) {
+				if (buf[i] == MAVLINK_STX) {
+					// Got MAVLink message, stop discovery
+					Serial.printf("Received MAVLink from " MACSTR "\n", MAC2STR(link->addr()));
+					if (DISABLE_SWARM) stop = true;
+				}
+			}
+		}
 		if (len > 0) {
 			Serial.write(buf, len);
 		}

tools/log_to_csv.py

@@ -0,0 +1,76 @@
+#!/usr/bin/env python3
+
+"""Convert flight from Flix format to CSV
+
+Usage:
+    log_to_csv.py <input_file>
+"""
+
+import os
+from pyflix import Flix
+import docopt
+import struct
+import csv
+
+DIR = os.path.dirname(os.path.realpath(__file__))
+HEADER_FILE = os.path.join(DIR, 'log/log_header.txt')
+
+# Read log header
+try:
+    # read from file
+    header = open(HEADER_FILE, 'r').read()
+except FileNotFoundError:
+    flix = Flix()
+    header = flix.cli('log header')  # receive the log schema
+    open(HEADER_FILE, 'w').write(header)  # save to file
+
+# Parse log header
+topics = []
+for line in header.splitlines():
+    if not line.startswith('  '):
+        topics.append([])
+    elif 'not logged' not in line:
+        topics[-1].append(line.strip())
+
+# Read log file
+args = docopt.docopt(__doc__)
+input_file = args['<input_file>']
+outfile_file = input_file + '.csv'
+data = open(input_file, 'rb').read()
+
+# Search for sync marker
+SYNC_MARKER = bytes.fromhex('1A 91 4F F6 7F')
+sync_offset = data.find(SYNC_MARKER)
+if sync_offset == -1:
+    raise ValueError('Sync marker not found in log file')
+data = data[sync_offset + len(SYNC_MARKER):]
+data = data.replace(SYNC_MARKER, b'')  # remove all other sync markers
+
+header_row = [f'{value}' for topic in topics for value in topic]
+rows = []
+
+offset = 0
+while offset < len(data):
+    try:
+        topic = struct.unpack_from('B', data, offset)[0]
+        offset += 1
+
+        if topic >= len(topics):
+            raise ValueError(f'Invalid topic {topic} at offset {offset}')
+
+        if topic == 0 or not rows:
+            rows.append({})
+
+        for name in topics[topic]:
+            value = struct.unpack_from('<f', data, offset)[0]
+            offset += 4
+            rows[-1][name] = value
+    except struct.error as e:
+        break
+
+# Write CSV file
+with open(outfile_file, 'w', newline='') as f:
+    writer = csv.DictWriter(f, fieldnames=header_row, extrasaction='ignore')
+    writer.writeheader()
+    rows = filter(lambda row: float(row.get('t', 0)), rows)
+    writer.writerows(rows)