diff --git a/docs/firmware.md b/docs/firmware.md
index b073d68..45ad004 100644
--- a/docs/firmware.md
+++ b/docs/firmware.md
@@ -13,7 +13,7 @@ The main loop is running at 1000 Hz. All the dataflow is happening through globa
 * `rates` *(Vector)* — filtered angular rates, *rad/s*.
 * `attitude` *(Quaternion)* — estimated attitude (orientation) of drone.
 * `controls` *(float[])* — user control inputs from the RC, normalized to [-1, 1] range.
-* `motors` *(float[])* — motor outputs, normalized to [-1, 1] range; reverse rotation is possible.
+* `motors` *(float[])* — motor outputs, normalized to [0, 1] range; reverse rotation is possible.
 
 ## Source files
 
diff --git a/flix/flix.ino b/flix/flix.ino
index f07619a..97212a4 100644
--- a/flix/flix.ino
+++ b/flix/flix.ino
@@ -25,7 +25,7 @@ Vector gyro; // gyroscope data
 Vector acc; // accelerometer data, m/s/s
 Vector rates; // filtered angular rates, rad/s
 Quaternion attitude; // estimated attitude
-float motors[4]; // normalized motors thrust in range [-1..1]
+float motors[4]; // normalized motors thrust in range [0..1]
 
 void setup() {
 	Serial.begin(SERIAL_BAUDRATE);
diff --git a/flix/imu.ino b/flix/imu.ino
index 0c5d1aa..e2b4b3f 100644
--- a/flix/imu.ino
+++ b/flix/imu.ino
@@ -10,9 +10,8 @@
 MPU9250 IMU(SPI);
 
 // NOTE: use 'ca' command to calibrate the accelerometer and put the values here
-Vector accBias(0, 0, 0);
+Vector accBias;
 Vector accScale(1, 1, 1);
-
 Vector gyroBias;
 
 void setupIMU() {
diff --git a/flix/motors.ino b/flix/motors.ino
index 6200b8c..79db78b 100644
--- a/flix/motors.ino
+++ b/flix/motors.ino
@@ -49,7 +49,7 @@ bool motorsActive() {
 	return motors[0] != 0 || motors[1] != 0 || motors[2] != 0 || motors[3] != 0;
 }
 
-void testMotor(uint8_t n) {
+void testMotor(int n) {
 	Serial.printf("Testing motor %d\n", n);
 	motors[n] = 1;
 	delay(50); // ESP32 may need to wait until the end of the current cycle to change duty https://github.com/espressif/arduino-esp32/issues/5306