Make motor subsystem configurable using parameters

Motor pins: MOT_PIN_FL, MOT_PIN_FR, MOT_PIN_RL, MOT_PIN_RR.
PWM configuration: MOT_PWM_FREQ, MOT_PWM_RES, MOT_PWM_STOP, MOT_PWM_MIN, MOT_PWM_MAX.
MOT_PWM_MAX = -1 chooses duty cycle mode for brushed motors (default).

docs/usage.md

@@ -134,6 +134,20 @@ Before flight you need to calibrate the accelerometer:
 1. Access the console using QGroundControl (recommended) or Serial Monitor.
 2. Type `ca` command there and follow the instructions.
 
+### Setup motors
+
+If using non-default motor pins, set the pin numbers using the parameters: `MOTOR_PIN_FL`, `MOTOR_PIN_FR`, `MOTOR_PIN_RL`, `MOTOR_PIN_RR` (front-left, front-right, rear-left, rear-right respectively).
+
+If using brushless motors and ESCs:
+
+1. Set the appropriate PWM using the parameters: `MOT_PWM_STOP`, `MOT_PWM_MIN`, and `MOT_PWM_MAX` (1000, 1000, and 2000 is typical).
+2. Decrease the PWM frequency using the `MOT_PWM_FREQ` parameter (400 is typical).
+
+Reboot the drone to apply the changes.
+
+> [!CAUTION]
+> **Remove the props when configuring the motors!** If improperly configured, you may not be able to stop them.
+
 ### Check everything works
 
 1. Check the IMU is working: perform `imu` command and check its output:

flix/motors.ino

@@ -1,24 +1,19 @@
 // Copyright (c) 2023 Oleg Kalachev <okalachev@gmail.com>
 // Repository: https://github.com/okalachev/flix
 
-// Motors output control using MOSFETs
+// PWM control for motors
-// In case of using ESCs, change PWM_STOP, PWM_MIN and PWM_MAX to appropriate values in μs, decrease PWM_FREQUENCY (to 400)
 
 #include "util.h"
 
-#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
-
 float motors[4]; // normalized motor thrusts in range [0..1]
 
+int motorPins[4] = {12, 13, 14, 15}; // default pin numbers
+int pwmFrequency = 78000;
+int pwmResolution = 10;
+int pwmStop = 0;
+int pwmMin = 0;
+int pwmMax = -1; // -1 means duty cycle mode
+
 const int MOTOR_REAR_LEFT = 0;
 const int MOTOR_REAR_RIGHT = 1;
 const int MOTOR_FRONT_RIGHT = 2;
@@ -26,30 +21,30 @@ const int MOTOR_FRONT_LEFT = 3;
 
 void setupMotors() {
 	print("Setup Motors\n");
-
 	// configure pins
-	ledcAttach(MOTOR_0_PIN, PWM_FREQUENCY, PWM_RESOLUTION);
+	for (int i = 0; i < 4; i++) {
-	ledcAttach(MOTOR_1_PIN, PWM_FREQUENCY, PWM_RESOLUTION);
+		ledcAttach(motorPins[i], pwmFrequency, pwmResolution);
-	ledcAttach(MOTOR_2_PIN, PWM_FREQUENCY, PWM_RESOLUTION);
+	}
-	ledcAttach(MOTOR_3_PIN, PWM_FREQUENCY, PWM_RESOLUTION);
-
 	sendMotors();
 	print("Motors initialized\n");
 }
 
-int getDutyCycle(float value) {
+void sendMotors() {
-	value = constrain(value, 0, 1);
+	for (int i = 0; i < 4; i++) {
-	float pwm = mapf(value, 0, 1, PWM_MIN, PWM_MAX);
+		ledcWrite(motorPins[i], getDutyCycle(motors[i]));
-	if (value == 0) pwm = PWM_STOP;
+	}
-	float duty = mapf(pwm, 0, 1000000 / PWM_FREQUENCY, 0, (1 << PWM_RESOLUTION) - 1);
-	return round(duty);
 }
 
-void sendMotors() {
+int getDutyCycle(float value) {
-	ledcWrite(MOTOR_0_PIN, getDutyCycle(motors[0]));
+	value = constrain(value, 0, 1);
-	ledcWrite(MOTOR_1_PIN, getDutyCycle(motors[1]));
+	if (pwmMax >= 0) { // pwm mode
-	ledcWrite(MOTOR_2_PIN, getDutyCycle(motors[2]));
+		float pwm = mapf(value, 0, 1, pwmMin, pwmMax);
-	ledcWrite(MOTOR_3_PIN, getDutyCycle(motors[3]));
+		if (value == 0) pwm = pwmStop;
+		float duty = mapf(pwm, 0, 1000000 / pwmFrequency, 0, (1 << pwmResolution) - 1);
+		return round(duty);
+	} else { // duty cycle mode
+		return round(value * ((1 << pwmResolution) - 1));
+	}
 }
 
 bool motorsActive() {

flix/parameters.ino

@@ -63,6 +63,16 @@ Parameter parameters[] = {
 	// estimate
 	{"EST_ACC_WEIGHT", &accWeight},
 	{"EST_RATES_LPF_A", &ratesFilter.alpha},
+	// motors
+	{"MOT_PIN_FL", &motorPins[MOTOR_FRONT_LEFT]},
+	{"MOT_PIN_FR", &motorPins[MOTOR_FRONT_RIGHT]},
+	{"MOT_PIN_RL", &motorPins[MOTOR_REAR_LEFT]},
+	{"MOT_PIN_RR", &motorPins[MOTOR_REAR_RIGHT]},
+	{"MOT_PWM_FREQ", &pwmFrequency},
+	{"MOT_PWM_RES", &pwmResolution},
+	{"MOT_PWM_STOP", &pwmStop},
+	{"MOT_PWM_MIN", &pwmMin},
+	{"MOT_PWM_MAX", &pwmMax},
 	// rc
 	{"RC_ZERO_0", &channelZero[0]},
 	{"RC_ZERO_1", &channelZero[1]},

gazebo/flix.h

@@ -32,6 +32,7 @@ void controlRates();
 void controlTorque();
 const char* getModeName();
 void sendMotors();
+int getDutyCycle(float value);
 bool motorsActive();
 void testMotor(int n);
 void print(const char* format, ...);