Add level calibration

.vscode/c_cpp_properties.json

@@ -18,7 +18,20 @@
 			"forcedInclude": [
 				"${workspaceFolder}/.vscode/intellisense.h",
 				"~/.arduino15/packages/esp32/hardware/esp32/3.2.0/cores/esp32/Arduino.h",
-				"~/.arduino15/packages/esp32/hardware/esp32/3.2.0/variants/d1_mini32/pins_arduino.h"
+				"~/.arduino15/packages/esp32/hardware/esp32/3.2.0/variants/d1_mini32/pins_arduino.h",
+				"${workspaceFolder}/flix/cli.ino",
+				"${workspaceFolder}/flix/control.ino",
+				"${workspaceFolder}/flix/estimate.ino",
+				"${workspaceFolder}/flix/flix.ino",
+				"${workspaceFolder}/flix/imu.ino",
+				"${workspaceFolder}/flix/led.ino",
+				"${workspaceFolder}/flix/log.ino",
+				"${workspaceFolder}/flix/mavlink.ino",
+				"${workspaceFolder}/flix/motors.ino",
+				"${workspaceFolder}/flix/rc.ino",
+				"${workspaceFolder}/flix/time.ino",
+				"${workspaceFolder}/flix/wifi.ino",
+				"${workspaceFolder}/flix/parameters.ino"
 			],
 			"compilerPath": "~/.arduino15/packages/esp32/tools/esp-x32/2411/bin/xtensa-esp32-elf-g++",
 			"cStandard": "c11",
@@ -52,7 +65,20 @@
 			"forcedInclude": [
 				"${workspaceFolder}/.vscode/intellisense.h",
 				"~/Library/Arduino15/packages/esp32/hardware/esp32/3.2.0/cores/esp32/Arduino.h",
-				"~/Library/Arduino15/packages/esp32/hardware/esp32/3.2.0/variants/d1_mini32/pins_arduino.h"
+				"~/Library/Arduino15/packages/esp32/hardware/esp32/3.2.0/variants/d1_mini32/pins_arduino.h",
+				"${workspaceFolder}/flix/flix.ino",
+				"${workspaceFolder}/flix/cli.ino",
+				"${workspaceFolder}/flix/control.ino",
+				"${workspaceFolder}/flix/estimate.ino",
+				"${workspaceFolder}/flix/imu.ino",
+				"${workspaceFolder}/flix/led.ino",
+				"${workspaceFolder}/flix/log.ino",
+				"${workspaceFolder}/flix/mavlink.ino",
+				"${workspaceFolder}/flix/motors.ino",
+				"${workspaceFolder}/flix/rc.ino",
+				"${workspaceFolder}/flix/time.ino",
+				"${workspaceFolder}/flix/wifi.ino",
+				"${workspaceFolder}/flix/parameters.ino"
 			],
 			"compilerPath": "~/Library/Arduino15/packages/esp32/tools/esp-x32/2411/bin/xtensa-esp32-elf-g++",
 			"cStandard": "c11",
@@ -87,7 +113,20 @@
 			"forcedInclude": [
 				"${workspaceFolder}/.vscode/intellisense.h",
 				"~/AppData/Local/Arduino15/packages/esp32/hardware/esp32/3.2.0/cores/esp32/Arduino.h",
-				"~/AppData/Local/Arduino15/packages/esp32/hardware/esp32/3.2.0/variants/d1_mini32/pins_arduino.h"
+				"~/AppData/Local/Arduino15/packages/esp32/hardware/esp32/3.2.0/variants/d1_mini32/pins_arduino.h",
+				"${workspaceFolder}/flix/cli.ino",
+				"${workspaceFolder}/flix/control.ino",
+				"${workspaceFolder}/flix/estimate.ino",
+				"${workspaceFolder}/flix/flix.ino",
+				"${workspaceFolder}/flix/imu.ino",
+				"${workspaceFolder}/flix/led.ino",
+				"${workspaceFolder}/flix/log.ino",
+				"${workspaceFolder}/flix/mavlink.ino",
+				"${workspaceFolder}/flix/motors.ino",
+				"${workspaceFolder}/flix/rc.ino",
+				"${workspaceFolder}/flix/time.ino",
+				"${workspaceFolder}/flix/wifi.ino",
+				"${workspaceFolder}/flix/parameters.ino"
 			],
 			"compilerPath": "~/AppData/Local/Arduino15/packages/esp32/tools/esp-x32/2411/bin/xtensa-esp32-elf-g++.exe",
 			"cStandard": "c11",

README.md

@@ -1,9 +1,6 @@
-<!-- markdownlint-disable MD041 -->
+# Flix
 
-<p align="center">
+**Flix** (*flight + X*) — open source ESP32-based quadcopter made from scratch.
-  <img src="docs/img/flix.svg" width=180 alt="Flix logo"><br>
-  <b>Flix</b> (<i>flight + X</i>) — open source ESP32-based quadcopter made from scratch.
-</p>
 
 <table>
   <tr>

docs/book/firmware.md

@@ -35,7 +35,7 @@
 
 ### Подсистема управления
 
-Состояние органов управления обрабатывается в функции `interpretControls()` и преобразуется в **команду управления**, которая включает следующее:
+Состояние органов управления обрабатывается в функции `interpretControls()` и преобразуется в *команду управления*, которая включает следующее:
 
 * `attitudeTarget` *(Quaternion)* — целевая ориентация дрона.
 * `ratesTarget` *(Vector)* — целевые угловые скорости, *рад/с*.

docs/firmware.md

@@ -38,13 +38,13 @@ Utility files:
 
 ### Control subsystem
 
-Pilot inputs are interpreted in `interpretControls()`, and then converted to the **control command**, which consists of the following:
+Pilot inputs are interpreted in `interpretControls()`, and then converted to the *control command*, which consists of the following:
 
 * `attitudeTarget` *(Quaternion)* — target attitude of the drone.
 * `ratesTarget` *(Vector)* — target angular rates, *rad/s*.
 * `ratesExtra` *(Vector)* — additional (feed-forward) angular rates , used for yaw rate control in STAB mode, *rad/s*.
 * `torqueTarget` *(Vector)* — target torque, range [-1, 1].
-* `thrustTarget` *(float)* — collective motor thrust target, range [0, 1].
+* `thrustTarget` *(float)* — collective thrust target, range [0, 1].
 
 Control command is handled in `controlAttitude()`, `controlRates()`, `controlTorque()` functions. Each function may be skipped if the corresponding control target is set to `NAN`.
 
@@ -62,11 +62,6 @@ print("Test value: %.2f\n", testValue);
 
 In order to add a console command, modify the `doCommand()` function in `cli.ino` file.
 
-> [!IMPORTANT]
-> Avoid using delays in in-flight commands, it will **crash** the drone! (The design is one-threaded.)
->
-> For on-the-ground commands, use `pause()` function, instead of `delay()`. This function allows to pause in a way that MAVLink connection will continue working.
-
 ## Building the firmware
 
 See build instructions in [usage.md](usage.md).

docs/img/flix.svg

@@ -1,38 +0,0 @@
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-  <defs>
-    <style>
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-        stroke-miterlimit: 10;
-        stroke-width: 31px;
-      }
-
-      .b {
-        fill: #c1c1c1;
-      }
-
-      .c {
-        fill: #ff9400;
-      }
-
-      .d {
-        fill: #d5d5d5;
-      }
-    </style>
-  </defs>
-  <g>
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-      <circle class="b" cx="549.27" cy="193.73" r="41.5"/>
-      <circle class="c" cx="449.35" cy="93.74" r="77.95"/>
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-      <circle class="c" cx="647.89" cy="294.51" r="77.95"/>
-      <circle class="c" cx="448.9" cy="294.51" r="77.95"/>
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-    <path class="d" d="M284.9,61.08V36.47a40.39,40.39,0,0,1,1.7-12.91,11.36,11.36,0,0,1,6.18-7,25.27,25.27,0,0,1,6.68-2.3c1.45-.15,4-.4,7.76-.72h25.23q10.43,0,16.73,4.7t6.31,18.22V62.05a27.94,27.94,0,0,1-.85,7.11,23,23,0,0,1-2.06,5.43,20,20,0,0,1-2.91,4,10,10,0,0,1-3.52,2.54c-1.21.48-2.54,1-4,1.44a11.53,11.53,0,0,1-3.4.73,13.71,13.71,0,0,0-3.15.48H307.7q-10.43,0-16.61-4.7T284.9,61.08Zm1.94,284.71V166.28q0-22.2,21.83-22.2h20.38q10.92,0,16.62,4t6.67,8.45a60.47,60.47,0,0,1,1,12.18V348.2q0,22.2-21.83,22.2H308.67q-10.43,0-15.64-4.95t-5.7-8.81A90.93,90.93,0,0,1,286.84,345.79Z"/>
-  </g>
-</svg>

docs/troubleshooting.md

@@ -4,7 +4,7 @@
 
 Do the following:
 
-* **Check ESP32 core is installed**. Check if the version matches the one used in the [tutorial](usage.md#building-the-firmware).
+* **Check ESP32 core is installed**. Check if the version matches the one used in the [tutorial](usage.md#firmware).
 * **Check libraries**. Install all the required libraries from the tutorial. Make sure there are no MPU9250 or other peripherals libraries that may conflict with the ones used in the tutorial.
 * **Check the chosen board**. The correct board to choose in Arduino IDE for ESP32 Mini is *WEMOS D1 MINI ESP32*.
 
@@ -25,7 +25,7 @@ Do the following:
   * The `accel` and `gyro` fields should change as you move the drone.
 * **Calibrate the accelerometer.** if is wasn't done before. Type `ca` command in Serial Monitor and follow the instructions.
 * **Check the attitude estimation**. Connect to the drone using QGroundControl. Rotate the drone in different orientations and check if the attitude estimation shown in QGroundControl is correct.
-* **Check the IMU orientation is set correctly**. If the attitude estimation is rotated, set the correct IMU orientation as described in the [tutorial](usage.md#define-imu-orientation).
+* **Check the IMU orientation is set correctly**. If the attitude estimation is rotated, make sure `rotateIMU` function is defined correctly in `imu.ino` file.
 * **Check the motors type**. Motors with exact 3.7V voltage are needed, not ranged working voltage (3.7V — 6V).
 * **Check the motors**. Perform the following commands using Serial Monitor:
   * `mfr` — should rotate front right motor (counter-clockwise).

docs/usage.md

@@ -80,7 +80,7 @@ QGroundControl is a ground control station software that can be used to monitor
 1. Install mobile or desktop version of [QGroundControl](https://docs.qgroundcontrol.com/master/en/qgc-user-guide/getting_started/download_and_install.html).
 2. Power up the drone.
 3. Connect your computer or smartphone to the appeared `flix` Wi-Fi network (password: `flixwifi`).
-4. Launch QGroundControl app. It should connect and begin showing the drone's telemetry automatically.
+4. Launch QGroundControl app. It should connect and begin showing the drone's telemetry automatically
 
 ### Access console
 
@@ -108,13 +108,11 @@ The drone is configured using parameters. To access and modify them, go to the Q
 
 <img src="img/parameters.png" width="400">
 
-You can also work with parameters using `p` command in the console.
-
 ### Define IMU orientation
 
 Use parameters, to define the IMU board axes orientation relative to the drone's axes: `IMU_ROT_ROLL`, `IMU_ROT_PITCH`, and `IMU_ROT_YAW`.
 
-The drone has *X* axis pointing forward, *Y* axis pointing left, and *Z* axis pointing up, and the supported IMU boards have *X* axis pointing to the pins side and *Z* axis pointing up from the component side:
+The drone has *X* axis pointing forward, *Y* axis pointing left, and *Z* axis pointing up, and the supported IMU boards have *X* axis pointing to the pins side and *Z* axis pointing up from the side with the components:
 
 <img src="img/imu-axes.png" width="200">
 
@@ -122,10 +120,10 @@ Use the following table to set the parameters for common IMU orientations:
 
 |Orientation|Parameters|Orientation|Parameters|
 |:-:|-|-|-|
-|<img src="img/imu-rot-1.png" width="180">|`IMU_ROT_ROLL` = 0<br>`IMU_ROT_PITCH` = 0<br>`IMU_ROT_YAW` = 0    |<img src="img/imu-rot-5.png" width="180">|`IMU_ROT_ROLL` = 3.142<br>`IMU_ROT_PITCH` = 0<br>`IMU_ROT_YAW` = 0|
+|<img src="img/imu-rot-1.png" width="200">|`IMU_ROT_ROLL` = 0<br>`IMU_ROT_PITCH` = 0<br>`IMU_ROT_YAW` = 0    |<img src="img/imu-rot-5.png" width="200">|`IMU_ROT_ROLL` = 3.142<br>`IMU_ROT_PITCH` = 0<br>`IMU_ROT_YAW` = 0|
-|<img src="img/imu-rot-2.png" width="180">|`IMU_ROT_ROLL` = 0<br>`IMU_ROT_PITCH` = 0<br>`IMU_ROT_YAW` = 1.571|<img src="img/imu-rot-6.png" width="180">|`IMU_ROT_ROLL` = 3.142<br>`IMU_ROT_PITCH` = 0<br>`IMU_ROT_YAW` = -1.571|
+|<img src="img/imu-rot-2.png" width="200">|`IMU_ROT_ROLL` = 0<br>`IMU_ROT_PITCH` = 0<br>`IMU_ROT_YAW` = 1.571|<img src="img/imu-rot-6.png" width="200">|`IMU_ROT_ROLL` = 3.142<br>`IMU_ROT_PITCH` = 0<br>`IMU_ROT_YAW` = -1.571|
-|<img src="img/imu-rot-3.png" width="180">|`IMU_ROT_ROLL` = 0<br>`IMU_ROT_PITCH` = 0<br>`IMU_ROT_YAW` = 3.142|<img src="img/imu-rot-7.png" width="180">|`IMU_ROT_ROLL` = 3.142<br>`IMU_ROT_PITCH` = 0<br>`IMU_ROT_YAW` = 3.142|
+|<img src="img/imu-rot-3.png" width="200">|`IMU_ROT_ROLL` = 0<br>`IMU_ROT_PITCH` = 0<br>`IMU_ROT_YAW` = 3.142|<img src="img/imu-rot-7.png" width="200">|`IMU_ROT_ROLL` = 3.142<br>`IMU_ROT_PITCH` = 0<br>`IMU_ROT_YAW` = 3.142|
-|<img src="img/imu-rot-4.png" width="180"><br>☑️ **Default**|<br>`IMU_ROT_ROLL` = 0<br>`IMU_ROT_PITCH` = 0<br>`IMU_ROT_YAW` = -1.571|<img src="img/imu-rot-8.png" width="180">|`IMU_ROT_ROLL` = 3.142<br>`IMU_ROT_PITCH` = 0<br>`IMU_ROT_YAW` = 1.571|
+|<img src="img/imu-rot-4.png" width="200"><br>☑️ **Default**|<br>`IMU_ROT_ROLL` = 0<br>`IMU_ROT_PITCH` = 0<br>`IMU_ROT_YAW` = -1.571|<img src="img/imu-rot-8.png" width="200">|`IMU_ROT_ROLL` = 3.142<br>`IMU_ROT_PITCH` = 0<br>`IMU_ROT_YAW` = 1.571|
 
 ### Calibrate accelerometer
 
@@ -154,10 +152,6 @@ Before flight you need to calibrate the accelerometer:
    * `mrl` — should rotate rear left motor (counter-clockwise).
    * `mrr` — should rotate rear right motor (clockwise).
 
-   Rotation diagram:
-
-   <img src="img/motors.svg" width=200>
-
 > [!WARNING]
 > Never run the motors when powering the drone from USB, always use the battery for that.
 
@@ -165,7 +159,7 @@ Before flight you need to calibrate the accelerometer:
 
 There are several ways to control the drone's flight: using **smartphone** (Wi-Fi), using **SBUS remote control**, or using **USB remote control** (Wi-Fi).
 
-### Control with a smartphone
+### Control with smartphone
 
 1. Install [QGroundControl mobile app](https://docs.qgroundcontrol.com/master/en/qgc-user-guide/getting_started/download_and_install.html#android) on your smartphone.
 2. Power the drone using the battery.
@@ -177,7 +171,7 @@ There are several ways to control the drone's flight: using **smartphone** (Wi-F
 > [!TIP]
 > Decrease `CTL_TILT_MAX` parameter when flying using the smartphone to make the controls less sensitive.
 
-### Control with a remote control
+### Control with remote control
 
 Before using remote SBUS-connected remote control, you need to calibrate it:
 
@@ -185,7 +179,7 @@ Before using remote SBUS-connected remote control, you need to calibrate it:
 2. Type `cr` command and follow the instructions.
 3. Use the remote control to fly the drone!
 
-### Control with a USB remote control
+### Control with USB remote control
 
 If your drone doesn't have RC receiver installed, you can use USB remote control and QGroundControl app to fly it.
 
@@ -243,6 +237,8 @@ In this mode, the pilot inputs are ignored (except the mode switch, if configure
 
 If the pilot moves the control sticks, the drone will switch back to *STAB* mode.
 
+<img src="img/parameters.png" width="400">
+
 ## Flight log
 
 After the flight, you can download the flight log for analysis wirelessly. Use the following for that:

docs/user.md

@@ -16,7 +16,7 @@ Author: [goldarte](https://t.me/goldarte).<br>
 
 ## School 548 course
 
-Special course on quadcopter design and engineering took place in october-november 2025 in School 548, Moscow. The course included UAV control theory, electronics, drone assembly and setup practice, using the Flix project.
+Special quadcopter design and engineering course took place in october-november 2025 in School 548, Moscow. Course included UAV control theory, electronics, and practical drone assembly and setup using the Flix project.
 
 <img height=200 src="img/user/school548/1.jpg"> <img height=200 src="img/user/school548/2.jpg"> <img height=200 src="img/user/school548/3.jpg">
 
@@ -25,7 +25,7 @@ STL files and other materials: see [here](https://drive.google.com/drive/folders
 ### Selected works
 
 Author: [KiraFlux](https://t.me/@kiraflux_0XC0000005).<br>
-Description: **custom ESPNOW remote control** was implemented, modified firmware to support ESPNOW protocol.<br>
+Description: **custom ESPNOW remote control** is implemented, firmware modified to support ESPNOW protocol.<br>
 Telegram posts: [1](https://t.me/opensourcequadcopter/106), [2](https://t.me/opensourcequadcopter/114).<br>
 Modified Flix firmware: https://github.com/KiraFlux/flix/tree/klyax.<br>
 Remote control project: https://github.com/KiraFlux/ESP32-DJC.<br>

flix/cli.ino

@@ -3,8 +3,6 @@
 
 // Implementation of command line interface
 
-#include <Arduino.h>
-#include "flix.h"
 #include "pid.h"
 #include "vector.h"
 #include "util.h"
@@ -13,7 +11,7 @@ extern const int MOTOR_REAR_LEFT, MOTOR_REAR_RIGHT, MOTOR_FRONT_RIGHT, MOTOR_FRO
 extern const int RAW, ACRO, STAB, AUTO;
 extern float t, dt, loopRate;
 extern uint16_t channels[16];
-extern float controlTime;
+extern float controlRoll, controlPitch, controlThrottle, controlYaw, controlMode;
 extern int mode;
 extern bool armed;
 
@@ -44,6 +42,7 @@ const char* motd =
 "log [dump] - print log header [and data]\n"
 "cr - calibrate RC\n"
 "ca - calibrate accel\n"
+"cl - calibrate level\n"
 "mfr, mfl, mrr, mrl - test motor (remove props)\n"
 "sys - show system info\n"
 "reset - reset drone's state\n"
@@ -73,7 +72,7 @@ void pause(float duration) {
 	}
 }
 
-void doCommand(String str, bool echo) {
+void doCommand(String str, bool echo = false) {
 	// parse command
 	String command, arg0, arg1;
 	splitString(str, command, arg0, arg1);
@@ -134,7 +133,6 @@ void doCommand(String str, bool echo) {
 		}
 		print("\nroll: %g pitch: %g yaw: %g throttle: %g mode: %g\n",
 			controlRoll, controlPitch, controlYaw, controlThrottle, controlMode);
-		print("time: %.1f\n", controlTime);
 		print("mode: %s\n", getModeName());
 		print("armed: %d\n", armed);
 	} else if (command == "wifi") {

flix/config.h

@@ -1,55 +0,0 @@
-// Wi-Fi
-#define WIFI_ENABLED 1
-#define WIFI_SSID "flix"
-#define WIFI_PASSWORD "flixwifi"
-#define WIFI_UDP_PORT 14550
-#define WIFI_UDP_REMOTE_PORT 14550
-#define WIFI_UDP_REMOTE_ADDR "255.255.255.255"
-
-// Motors
-#define MOTOR_0_PIN 12 // rear left
-#define MOTOR_1_PIN 13 // rear right
-#define MOTOR_2_PIN 14 // front right
-#define MOTOR_3_PIN 15 // front left
-#define PWM_FREQUENCY 78000
-#define PWM_RESOLUTION 10
-#define PWM_STOP 0
-#define PWM_MIN 0
-#define PWM_MAX 1000000 / PWM_FREQUENCY
-
-// Control
-#define PITCHRATE_P 0.05
-#define PITCHRATE_I 0.2
-#define PITCHRATE_D 0.001
-#define PITCHRATE_I_LIM 0.3
-#define ROLLRATE_P PITCHRATE_P
-#define ROLLRATE_I PITCHRATE_I
-#define ROLLRATE_D PITCHRATE_D
-#define ROLLRATE_I_LIM PITCHRATE_I_LIM
-#define YAWRATE_P 0.3
-#define YAWRATE_I 0.0
-#define YAWRATE_D 0.0
-#define YAWRATE_I_LIM 0.3
-#define ROLL_P 6
-#define ROLL_I 0
-#define ROLL_D 0
-#define PITCH_P ROLL_P
-#define PITCH_I ROLL_I
-#define PITCH_D ROLL_D
-#define YAW_P 3
-#define PITCHRATE_MAX radians(360)
-#define ROLLRATE_MAX radians(360)
-#define YAWRATE_MAX radians(300)
-#define TILT_MAX radians(30)
-#define RATES_D_LPF_ALPHA 0.2 // cutoff frequency ~ 40 Hz
-
-// Estimation
-#define WEIGHT_ACC 0.003
-#define RATES_LFP_ALPHA 0.2 // cutoff frequency ~ 40 Hz
-
-// MAVLink
-#define SYSTEM_ID 1
-
-// Safety
-#define RC_LOSS_TIMEOUT 1
-#define DESCEND_TIME 10

flix/control.ino

@@ -3,25 +3,41 @@
 
 // Flight control
 
-#include "config.h"
-#include "flix.h"
 #include "vector.h"
 #include "quaternion.h"
 #include "pid.h"
 #include "lpf.h"
 #include "util.h"
 
-extern const int RAW = 0, ACRO = 1, STAB = 2, AUTO = 3; // flight modes
+#define PITCHRATE_P 0.05
+#define PITCHRATE_I 0.2
+#define PITCHRATE_D 0.001
+#define PITCHRATE_I_LIM 0.3
+#define ROLLRATE_P PITCHRATE_P
+#define ROLLRATE_I PITCHRATE_I
+#define ROLLRATE_D PITCHRATE_D
+#define ROLLRATE_I_LIM PITCHRATE_I_LIM
+#define YAWRATE_P 0.3
+#define YAWRATE_I 0.0
+#define YAWRATE_D 0.0
+#define YAWRATE_I_LIM 0.3
+#define ROLL_P 6
+#define ROLL_I 0
+#define ROLL_D 0
+#define PITCH_P ROLL_P
+#define PITCH_I ROLL_I
+#define PITCH_D ROLL_D
+#define YAW_P 3
+#define PITCHRATE_MAX radians(360)
+#define ROLLRATE_MAX radians(360)
+#define YAWRATE_MAX radians(300)
+#define TILT_MAX radians(30)
+#define RATES_D_LPF_ALPHA 0.2 // cutoff frequency ~ 40 Hz
 
+const int RAW = 0, ACRO = 1, STAB = 2, AUTO = 3; // flight modes
 int mode = STAB;
 bool armed = false;
 
-Quaternion attitudeTarget;
-Vector ratesTarget;
-Vector ratesExtra; // feedforward rates
-Vector torqueTarget;
-float thrustTarget;
-
 PID rollRatePID(ROLLRATE_P, ROLLRATE_I, ROLLRATE_D, ROLLRATE_I_LIM, RATES_D_LPF_ALPHA);
 PID pitchRatePID(PITCHRATE_P, PITCHRATE_I, PITCHRATE_D, PITCHRATE_I_LIM, RATES_D_LPF_ALPHA);
 PID yawRatePID(YAWRATE_P, YAWRATE_I, YAWRATE_D);
@@ -31,6 +47,12 @@ PID yawPID(YAW_P, 0, 0);
 Vector maxRate(ROLLRATE_MAX, PITCHRATE_MAX, YAWRATE_MAX);
 float tiltMax = TILT_MAX;
 
+Quaternion attitudeTarget;
+Vector ratesTarget;
+Vector ratesExtra; // feedforward rates
+Vector torqueTarget;
+float thrustTarget;
+
 extern const int MOTOR_REAR_LEFT, MOTOR_REAR_RIGHT, MOTOR_FRONT_RIGHT, MOTOR_FRONT_LEFT;
 extern float controlRoll, controlPitch, controlThrottle, controlYaw, controlMode;
 

flix/estimate.ino

@@ -3,17 +3,11 @@
 
 // Attitude estimation from gyro and accelerometer
 
-#include "config.h"
-#include "flix.h"
 #include "quaternion.h"
 #include "vector.h"
 #include "lpf.h"
 #include "util.h"
 
-Vector rates; // estimated angular rates, rad/s
-Quaternion attitude; // estimated attitude
-bool landed;
-
 float accWeight = 0.003;
 LowPassFilter<Vector> ratesFilter(0.2); // cutoff frequency ~ 40 Hz
 

flix/flix.h

@@ -1,90 +0,0 @@
-// Copyright (c) 2023 Oleg Kalachev <okalachev@gmail.com>
-// Repository: https://github.com/okalachev/flix
-
-// All-in-one header file
-
-#pragma once
-
-#include <Arduino.h>
-#include "vector.h"
-#include "quaternion.h"
-
-extern float t, dt;
-extern float loopRate;
-extern float controlRoll, controlPitch, controlYaw, controlThrottle, controlMode;
-extern Vector gyro, acc;
-extern Vector rates;
-extern Quaternion attitude;
-extern bool landed;
-extern int mode;
-extern bool armed;
-extern Quaternion attitudeTarget;
-extern Vector ratesTarget, ratesExtra, torqueTarget;
-extern float thrustTarget;
-extern float motors[4];
-
-void print(const char* format, ...);
-void pause(float duration);
-void doCommand(String str, bool echo = false);
-void handleInput();
-void control();
-void interpretControls();
-void controlAttitude();
-void controlRates();
-void controlTorque();
-const char *getModeName();
-void estimate();
-void applyGyro();
-void applyAcc();
-void setupIMU();
-void configureIMU();
-void readIMU();
-void rotateIMU(Vector& data);
-void calibrateGyroOnce();
-void calibrateAccel();
-void calibrateAccelOnce();
-void printIMUCalibration();
-void printIMUInfo();
-void setupLED();
-void setLED(bool on);
-void blinkLED();
-void prepareLogData();
-void logData();
-void printLogHeader();
-void printLogData();
-void processMavlink();
-void sendMavlink();
-void sendMessage(const void *msg);
-void receiveMavlink();
-void handleMavlink(const void *_msg);
-void mavlinkPrint(const char* str);
-void sendMavlinkPrint();
-void setupMotors();
-int getDutyCycle(float value);
-void sendMotors();
-bool motorsActive();
-void testMotor(int n);
-void setupParameters();
-int parametersCount();
-const char *getParameterName(int index);
-float getParameter(int index);
-float getParameter(const char *name);
-bool setParameter(const char *name, const float value);
-void syncParameters();
-void printParameters();
-void resetParameters();
-void setupRC();
-bool readRC();
-void normalizeRC();
-void calibrateRC();
-void calibrateRCChannel(float *channel, uint16_t in[16], uint16_t out[16], const char *str);
-void printRCCalibration();
-void failsafe();
-void rcLossFailsafe();
-void descend();
-void autoFailsafe();
-void step();
-void computeLoopRate();
-void setupWiFi();
-void sendWiFi(const uint8_t *buf, int len);
-int receiveWiFi(uint8_t *buf, int len);

flix/flix.ino

@@ -3,11 +3,22 @@
 
 // Main firmware file
 
-#include "config.h"
 #include "vector.h"
 #include "quaternion.h"
 #include "util.h"
-#include "flix.h"
+
+#define WIFI_ENABLED 1
+
+float t = NAN; // current step time, s
+float dt; // time delta from previous step, s
+float controlRoll, controlPitch, controlYaw, controlThrottle; // pilot's inputs, range [-1, 1]
+float controlMode = NAN;
+Vector gyro; // gyroscope data
+Vector acc; // accelerometer data, m/s/s
+Vector rates; // filtered angular rates, rad/s
+Quaternion attitude; // estimated attitude
+bool landed; // are we landed and stationary
+float motors[4]; // normalized motors thrust in range [0..1]
 
 void setup() {
 	Serial.begin(115200);

flix/imu.ino

@@ -12,12 +12,9 @@
 MPU9250 imu(SPI);
 Vector imuRotation(0, 0, -PI / 2); // imu orientation as Euler angles
 
-Vector gyro; // gyroscope output, rad/s
-Vector gyroBias;
-
-Vector acc; // accelerometer output, m/s/s
 Vector accBias;
 Vector accScale(1, 1, 1);
+Vector gyroBias;
 
 void setupIMU() {
 	print("Setup IMU\n");
@@ -47,6 +44,14 @@ void readIMU() {
 	gyro = Quaternion::rotateVector(gyro, rotation.inversed());
 }
 
+void calibrateLevel() {
+	print("Place perfectly level [1 sec]\n");
+	pause(1);
+	Quaternion correction = Quaternion::fromBetweenVectors(Quaternion::rotateVector(Vector(0, 0, 1), attitude), Vector(0, 0, 1));
+	imuRotation = Quaternion::rotate(correction, Quaternion::fromEuler(imuRotation)).toEuler();
+	print("✓ Done: %.3f %.3f %.3f\n", degrees(imuRotation.x), degrees(imuRotation.y), degrees(imuRotation.z));
+}
+
 void calibrateGyroOnce() {
 	static Delay landedDelay(2);
 	if (!landedDelay.update(landed)) return; // calibrate only if definitely stationary

flix/led.ino

@@ -3,8 +3,6 @@
 
 // Board's LED control
 
-#include <Arduino.h>
-
 #define BLINK_PERIOD 500000
 
 #ifndef LED_BUILTIN

flix/log.ino

@@ -3,7 +3,6 @@
 
 // In-RAM logging
 
-#include "flix.h"
 #include "vector.h"
 #include "util.h"
 

flix/lpf.h

@@ -5,8 +5,6 @@
 
 #pragma once
 
-#include <Arduino.h>
-
 template <typename T> // Using template to make the filter usable for scalar and vector values
 class LowPassFilter {
 public:

flix/mavlink.ino

@@ -3,10 +3,6 @@
 
 // MAVLink communication
 
-#include <Arduino.h>
-#include "config.h"
-#include "flix.h"
-
 #if WIFI_ENABLED
 
 #include <MAVLink.h>
@@ -16,13 +12,12 @@
 #define MAVLINK_RATE_SLOW 1
 #define MAVLINK_RATE_FAST 10
 
-extern const int AUTO, STAB;
-extern uint16_t channels[16];
-extern float controlTime;
-
 bool mavlinkConnected = false;
 String mavlinkPrintBuffer;
 
+extern float controlTime;
+extern float controlRoll, controlPitch, controlThrottle, controlYaw, controlMode;
+
 void processMavlink() {
 	sendMavlink();
 	receiveMavlink();
@@ -212,7 +207,6 @@ void handleMavlink(const void *_msg) {
 		armed = motors[0] > 0 || motors[1] > 0 || motors[2] > 0 || motors[3] > 0;
 	}
 
-	/* TODO:
 	if (msg.msgid == MAVLINK_MSG_ID_LOG_REQUEST_DATA) {
 		mavlink_log_request_data_t m;
 		mavlink_msg_log_request_data_decode(&msg, &m);
@@ -226,7 +220,6 @@ void handleMavlink(const void *_msg) {
 			sendMessage(&msg);
 		}
 	}
-	*/
 
 	// Handle commands
 	if (msg.msgid == MAVLINK_MSG_ID_COMMAND_LONG) {

flix/motors.ino

@@ -4,17 +4,24 @@
 // Motors output control using MOSFETs
 // In case of using ESCs, change PWM_STOP, PWM_MIN and PWM_MAX to appropriate values in μs, decrease PWM_FREQUENCY (to 400)
 
-#include <Arduino.h>
-#include "config.h"
-#include "flix.h"
 #include "util.h"
 
-float motors[4]; // normalized motor thrusts in range [0..1]
+#define MOTOR_0_PIN 12 // rear left
+#define MOTOR_1_PIN 13 // rear right
+#define MOTOR_2_PIN 14 // front right
+#define MOTOR_3_PIN 15 // front left
 
-extern const int MOTOR_REAR_LEFT = 0;
+#define PWM_FREQUENCY 78000
-extern const int MOTOR_REAR_RIGHT = 1;
+#define PWM_RESOLUTION 10
-extern const int MOTOR_FRONT_RIGHT = 2;
+#define PWM_STOP 0
-extern const int MOTOR_FRONT_LEFT = 3;
+#define PWM_MIN 0
+#define PWM_MAX 1000000 / PWM_FREQUENCY
+
+// Motors array indexes:
+const int MOTOR_REAR_LEFT = 0;
+const int MOTOR_REAR_RIGHT = 1;
+const int MOTOR_FRONT_RIGHT = 2;
+const int MOTOR_FRONT_LEFT = 3;
 
 void setupMotors() {
 	print("Setup Motors\n");

flix/parameters.ino

@@ -4,22 +4,11 @@
 // Parameters storage in flash memory
 
 #include <Preferences.h>
-#include "flix.h"
-#include "pid.h"
-#include "lpf.h"
 #include "util.h"
 
 extern float channelZero[16];
 extern float channelMax[16];
 extern float rollChannel, pitchChannel, throttleChannel, yawChannel, armedChannel, modeChannel;
-extern float tiltMax;
-extern PID rollPID, pitchPID, yawPID;
-extern PID rollRatePID, pitchRatePID, yawRatePID;
-extern Vector maxRate;
-extern Vector imuRotation;
-extern Vector accBias, accScale;
-extern float accWeight;
-extern LowPassFilter<Vector> ratesFilter;
 
 Preferences storage;
 

flix/pid.h

@@ -5,8 +5,6 @@
 
 #pragma once
 
-#include "Arduino.h"
-#include "flix.h"
 #include "lpf.h"
 
 class PID {

flix/quaternion.h

@@ -5,7 +5,6 @@
 
 #pragma once
 
-#include <Arduino.h>
 #include "vector.h"
 
 class Quaternion : public Printable {

flix/rc.ino

@@ -6,16 +6,13 @@
 #include <SBUS.h>
 #include "util.h"
 
-SBUS rc(Serial2);
+SBUS rc(Serial2); // NOTE: Use RC(Serial2, 16, 17) if you use the old UART2 pins
 
 uint16_t channels[16]; // raw rc channels
+float controlTime; // time of the last controls update
 float channelZero[16]; // calibration zero values
 float channelMax[16]; // calibration max values
 
-float controlRoll, controlPitch, controlYaw, controlThrottle; // pilot's inputs, range [-1, 1]
-float controlMode = NAN; //
-float controlTime; // time of the last controls update (0 when no RC)
-
 // Channels mapping (using float to store in parameters):
 float rollChannel = NAN, pitchChannel = NAN, throttleChannel = NAN, yawChannel = NAN, modeChannel = NAN;
 
@@ -41,11 +38,11 @@ void normalizeRC() {
 		controls[i] = mapf(channels[i], channelZero[i], channelMax[i], 0, 1);
 	}
 	// Update control values
-	controlRoll = rollChannel >= 0 ? controls[(int)rollChannel] : 0;
+	controlRoll = rollChannel >= 0 ? controls[(int)rollChannel] : NAN;
-	controlPitch = pitchChannel >= 0 ? controls[(int)pitchChannel] : 0;
+	controlPitch = pitchChannel >= 0 ? controls[(int)pitchChannel] : NAN;
-	controlYaw = yawChannel >= 0 ? controls[(int)yawChannel] : 0;
+	controlYaw = yawChannel >= 0 ? controls[(int)yawChannel] : NAN;
-	controlThrottle = throttleChannel >= 0 ? controls[(int)throttleChannel] : 0;
+	controlThrottle = throttleChannel >= 0 ? controls[(int)throttleChannel] : NAN;
-	controlMode = modeChannel >= 0 ? controls[(int)modeChannel] : NAN; // mode switch should not have affect if not set
+	controlMode = modeChannel >= 0 ? controls[(int)modeChannel] : NAN;
 }
 
 void calibrateRC() {

flix/safety.ino

@@ -3,11 +3,11 @@
 
 // Fail-safe functions
 
-#include "config.h"
+#define RC_LOSS_TIMEOUT 1
-#include "flix.h"
+#define DESCEND_TIME 10
 
 extern float controlTime;
-extern const int AUTO, STAB;
+extern float controlRoll, controlPitch, controlThrottle, controlYaw;
 
 void failsafe() {
 	rcLossFailsafe();

flix/time.ino

@@ -3,11 +3,6 @@
 
 // Time related functions
 
-#include "Arduino.h"
-#include "flix.h"
-
-float t = NAN; // current time, s
-float dt; // time delta with the previous step, s
 float loopRate; // Hz
 
 void step() {

flix/util.h

@@ -8,24 +8,24 @@
 #include <math.h>
 #include <soc/soc.h>
 #include <soc/rtc_cntl_reg.h>
-#include "flix.h"
 
 const float ONE_G = 9.80665;
+extern float t;
 
-inline float mapf(float x, float in_min, float in_max, float out_min, float out_max) {
+float mapf(float x, float in_min, float in_max, float out_min, float out_max) {
 	return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
 }
 
-inline bool invalid(float x) {
+bool invalid(float x) {
 	return !isfinite(x);
 }
 
-inline bool valid(float x) {
+bool valid(float x) {
 	return isfinite(x);
 }
 
 // Wrap angle to [-PI, PI)
-inline float wrapAngle(float angle) {
+float wrapAngle(float angle) {
 	angle = fmodf(angle, 2 * PI);
 	if (angle > PI) {
 		angle -= 2 * PI;
@@ -36,12 +36,12 @@ inline float wrapAngle(float angle) {
 }
 
 // Disable reset on low voltage
-inline void disableBrownOut() {
+void disableBrownOut() {
 	REG_CLR_BIT(RTC_CNTL_BROWN_OUT_REG, RTC_CNTL_BROWN_OUT_ENA);
 }
 
 // Trim and split string by spaces
-inline void splitString(String& str, String& token0, String& token1, String& token2) {
+void splitString(String& str, String& token0, String& token1, String& token2) {
 	str.trim();
 	char chars[str.length() + 1];
 	str.toCharArray(chars, str.length() + 1);

flix/vector.h

@@ -5,8 +5,6 @@
 
 #pragma once
 
-#include <Arduino.h>
-
 class Vector : public Printable {
 public:
 	float x, y, z;
@@ -37,6 +35,7 @@ public:
 		z = NAN;
 	}
 
+
 	float norm() const {
 		return sqrt(x * x + y * y + z * z);
 	}
@@ -125,5 +124,5 @@ public:
 	}
 };
 
-inline Vector operator * (const float a, const Vector& b) { return b * a; }
+Vector operator * (const float a, const Vector& b) { return b * a; }
-inline Vector operator + (const float a, const Vector& b) { return b + a; }
+Vector operator + (const float a, const Vector& b) { return b + a; }

flix/wifi.ino

@@ -3,18 +3,19 @@
 
 // Wi-Fi support
 
-#include "config.h"
-#include "flix.h"
-
 #if WIFI_ENABLED
 
 #include <WiFi.h>
 #include <WiFiAP.h>
 #include <WiFiUdp.h>
 
-WiFiUDP udp;
+#define WIFI_SSID "flix"
+#define WIFI_PASSWORD "flixwifi"
+#define WIFI_UDP_PORT 14550
+#define WIFI_UDP_REMOTE_PORT 14550
+#define WIFI_UDP_REMOTE_ADDR "255.255.255.255"
 
-extern bool mavlinkConnected;
+WiFiUDP udp;
 
 void setupWiFi() {
 	print("Setup Wi-Fi\n");

gazebo/CMakeLists.txt

@@ -10,23 +10,9 @@ list(APPEND CMAKE_CXX_FLAGS "${GAZEBO_CXX_FLAGS}")
 
 set(FLIX_SOURCE_DIR ../flix)
 include_directories(${FLIX_SOURCE_DIR})
-set(FLIX_SOURCE_DIR ../flix)
-include_directories(${FLIX_SOURCE_DIR})
-set(FLIX_SOURCES
-  ${FLIX_SOURCE_DIR}/cli.cpp
-  ${FLIX_SOURCE_DIR}/control.cpp
-  ${FLIX_SOURCE_DIR}/estimate.cpp
-  ${FLIX_SOURCE_DIR}/safety.cpp
-  ${FLIX_SOURCE_DIR}/log.cpp
-  ${FLIX_SOURCE_DIR}/mavlink.cpp
-  ${FLIX_SOURCE_DIR}/motors.cpp
-  ${FLIX_SOURCE_DIR}/parameters.cpp
-  ${FLIX_SOURCE_DIR}/rc.cpp
-  ${FLIX_SOURCE_DIR}/time.cpp
-)
 
 set(CMAKE_BUILD_TYPE RelWithDebInfo)
-add_library(flix SHARED simulator.cpp ${FLIX_SOURCES})
+add_library(flix SHARED simulator.cpp)
 target_link_libraries(flix ${GAZEBO_LIBRARIES} ${SDL2_LIBRARIES})
 target_include_directories(flix PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
 target_compile_options(flix PRIVATE -Wno-address-of-packed-member) # disable unneeded mavlink warnings

gazebo/flix.h

@@ -12,15 +12,17 @@
 
 #define WIFI_ENABLED 1
 
-extern float t, dt;
+float t = NAN;
-extern float controlRoll, controlPitch, controlYaw, controlThrottle, controlMode;
+float dt;
-extern Vector rates;
+float motors[4];
-extern Quaternion attitude;
+float controlRoll, controlPitch, controlYaw, controlThrottle = NAN;
-extern bool landed;
+float controlMode = NAN;
-extern float motors[4];
+Vector acc;
-
+Vector gyro;
-Vector gyro, acc, imuRotation;
+Vector rates;
-Vector accBias, gyroBias, accScale(1, 1, 1);
+Quaternion attitude;
+bool landed;
+Vector imuRotation;
 
 // declarations
 void step();
@@ -73,3 +75,4 @@ void calibrateAccel() { print("Skip accel calibrating\n"); };
 void printIMUCalibration() { print("cal: N/A\n"); };
 void printIMUInfo() {};
 void printWiFiInfo() {};
+Vector accBias, gyroBias, accScale(1, 1, 1);

gazebo/simulator.cpp

@@ -18,6 +18,18 @@
 #include "Arduino.h"
 #include "flix.h"
 
+#include "cli.ino"
+#include "control.ino"
+#include "estimate.ino"
+#include "safety.ino"
+#include "log.ino"
+#include "lpf.h"
+#include "mavlink.ino"
+#include "motors.ino"
+#include "parameters.ino"
+#include "rc.ino"
+#include "time.ino"
+
 using ignition::math::Vector3d;
 using namespace gazebo;
 using namespace std;

tools/pyflix/README.md

@@ -95,7 +95,7 @@ Full list of events:
 |`armed`|Armed state update|Armed state (*bool*)|
 |`mode`|Flight mode update|Flight mode (*str*)|
 |`landed`|Landed state update|Landed state (*bool*)|
-|`print`|The drone prints text to the console|Text|
+|`print`|The drone sends text to the console|Text|
 |`attitude`|Attitude update|Attitude quaternion (*list*)|
 |`attitude_euler`|Attitude update|Euler angles (*list*)|
 |`rates`|Angular rates update|Angular rates (*list*)|
@@ -112,7 +112,7 @@ Full list of events:
 > [!NOTE]
 > Update events trigger on every new piece of data from the drone, and do not mean the value has changed.
 
-### Basic methods
+### Common methods
 
 Get and set firmware parameters using `get_param` and `set_param` methods: