diff --git a/flix/cli.ino b/flix/cli.ino
index 510ccf2..fca2bf8 100644
--- a/flix/cli.ino
+++ b/flix/cli.ino
@@ -5,10 +5,6 @@
 
 #include "pid.h"
 
-static String command;
-static String value;
-static bool parsingCommand = true;
-
 extern PID rollRatePID, pitchRatePID, yawRatePID, rollPID, pitchPID;
 
 const char* motd =
@@ -34,8 +30,6 @@ const char* motd =
 "fullmot <n> - test motor on all signals\n"
 "wifi - start wi-fi access point\n";
 
-bool showMotd = true;
-
 static const struct Param {
 	const char* name;
 	float* value;
@@ -57,7 +51,7 @@ static const struct Param {
 	// {"m", &mode, nullptr},
 };
 
-static void doCommand()
+static void doCommand(String& command, String& value)
 {
 	if (command == "help" || command == "motd") {
 		Serial.println(motd);
@@ -138,6 +132,11 @@ static void cliTestMotor(uint8_t n)
 
 void parseInput()
 {
+	static bool showMotd = true;
+	static String command;
+	static String value;
+	static bool parsingCommand = true;
+
 	if (showMotd) {
 		Serial.println(motd);
 		showMotd = false;
@@ -148,7 +147,7 @@ void parseInput()
 		if (c == '\n') {
 			parsingCommand = true;
 			if (!command.isEmpty()) {
-				doCommand();
+				doCommand(command, value);
 			}
 			command.clear();
 			value.clear();
diff --git a/flix/flix.ino b/flix/flix.ino
index 9828941..d474575 100644
--- a/flix/flix.ino
+++ b/flix/flix.ino
@@ -26,7 +26,6 @@ float dt; // time delta from previous step, s
 float loopFreq; // loop frequency, Hz
 uint16_t channels[16]; // raw rc channels
 float controls[RC_CHANNELS]; // normalized controls in range [-1..1] ([0..1] for throttle)
-uint32_t rcFailSafe, rcLostFrame;
 float motors[4]; // normalized motors thrust in range [-1..1]
 Vector rates; // angular rates, rad/s
 Vector acc; // accelerometer data, m/s/s
diff --git a/flix/motors.ino b/flix/motors.ino
index d0c2cd6..3113cca 100644
--- a/flix/motors.ino
+++ b/flix/motors.ino
@@ -1,46 +1,25 @@
 // Copyright (c) 2023 Oleg Kalachev <okalachev@gmail.com>
 // Repository: https://github.com/okalachev/flix
 
-// https://habr.com/ru/company/first/blog/664922/
-// esc: https://aliexpress.com/item/4000280617058.html (KINGDUO Micro Mini 4A 1S Brushed Esc 3.6-6V)
-// motor: https://aliexpress.com/item/32731613504.html (8520 3.7V)
+// Motors output
+// Motor: 8520 3.7V
+// ESC: KINGDUO Micro Mini 4A 1S Brushed Esc 3.6-6V
 
 #define MOTOR_0_PIN 12
 #define MOTOR_1_PIN 13
 #define MOTOR_2_PIN 14
 #define MOTOR_3_PIN 15
 
-// #define PWM_FREQUENCY 200
-// #define PWM_FREQUENCY 50 // TODO: way low frequency considering the IMU is 1kHz
-#define PWM_FREQUENCY 200 // WARNING: original 50
-
+#define PWM_FREQUENCY 200
 #define PWM_RESOLUTION 8
 
-// #define PWM_MIN 1575
-// #define PWM_MAX 2300
 #define PWM_NEUTRAL 1500
-// #define PWM_REVERSE_MAX 700
-// #define PWM_REVERSE_MIN 1425
 
-// static const uint16_t pwmMin[] = {1600-50, 1600-50, 1600-50, 1600-50};
-// static const uint16_t pwmMax[] = {2100, 2300, 2000, 2000}; // NOTE: ORIGINAL
-
-static const uint16_t pwmMin[] = {1600, 1600, 1600, 1600}; // NOTE: success
-// static const uint16_t pwmMax[] = {2000, 2000, 2000, 2000}; // NOTE: success
+static const uint16_t pwmMin[] = {1600, 1600, 1600, 1600};
 static const uint16_t pwmMax[] = {2300, 2300, 2300, 2300};
-// from esc description
-// static const uint16_t pwmMin[] = {1600, 1600, 1600, 1600};
-// static const uint16_t pwmMax[] = {2300, 2300, 2300, 2300};
-
-// static const uint16_t pwmReverseMin[] = {1420+50, 1440+50, 1440+50, 1440+50};
-
-// static const uint16_t pwmReverseMin[] = {1420, 1440, 1440, 1440};
-// static const uint16_t pwmReverseMax[] = {700, 1100, 1100, 1100}; // NOTE: ???
 static const uint16_t pwmReverseMin[] = {1390, 1440, 1440, 1440};
 static const uint16_t pwmReverseMax[] = {1100, 1100, 1100, 1100};
 
-bool useBreak; // TODO: redesign
-
 void setupMotors() {
 	Serial.println("Setup Motors");
 
@@ -56,12 +35,6 @@ void setupMotors() {
 	ledcAttachPin(MOTOR_2_PIN, 2);
 	ledcAttachPin(MOTOR_3_PIN, 3);
 
-	// send initial break to initialize ESCs
-	// Serial.println("Calibrating ESCs");
-	// useBreak = true;
-	// sendMotors();
-	// delay(2000);
-	// useBreak = false;
 	sendMotors();
 	Serial.println("Motors initialized");
 }
@@ -69,7 +42,7 @@ void setupMotors() {
 static uint16_t getPWM(float val, int n)
 {
 	if (val == 0) {
-		return PWM_NEUTRAL; // useBreak ? PWM_NEUTRAL : 0;
+		return PWM_NEUTRAL;
 	} else if (val > 0) {
 		return mapff(val, 0, 1, pwmMin[n], pwmMax[n]);
 	} else {
diff --git a/flix/rc.ino b/flix/rc.ino
index 73f3561..bf02ecd 100644
--- a/flix/rc.ino
+++ b/flix/rc.ino
@@ -18,8 +18,8 @@ void readRC()
 {
 	bool failSafe, lostFrame;
 	if (RC.read(channels, &failSafe, &lostFrame)) {
-		if (failSafe) { rcFailSafe++; return; } // TODO: NOT TESTED YET
-		if (lostFrame) { rcLostFrame++; return; }
+		if (failSafe) { return; } // TODO:
+		if (lostFrame) { return; }
 		normalizeRC();
 	}
 }
diff --git a/gazebo/Arduino.h b/gazebo/Arduino.h
index 6e29617..a18bbbf 100644
--- a/gazebo/Arduino.h
+++ b/gazebo/Arduino.h
@@ -36,9 +36,9 @@ class __FlashStringHelper;
 // https://www.arduino.cc/reference/en/language/variables/data-types/stringobject/
 class String: public std::string {
 public:
-	long toInt() { return atol(this->c_str()); }
-	float toFloat() { return atof(this->c_str()); }
-	bool isEmpty() { return this->empty(); }
+	long toInt() const { return atol(this->c_str()); }
+	float toFloat() const { return atof(this->c_str()); }
+	bool isEmpty() const { return this->empty(); }
 };
 
 class Print;