Use 'loop rate' term instead of misleading 'loop frequency'

docs/troubleshooting.md

@@ -23,7 +23,7 @@ Do the following:
 * **Check the RC data** if you use it. Use `rc` command, `Control` should show correct values between -1 and 1, and between 0 and 1 for the throttle.
 * **Configure QGroundControl correctly before connecting to the drone** if you use it to control the drone. Go to the settings and enable *Virtual Joystick*. *Auto-Center Throttle* setting **should be disabled**.
 * **Make sure you're not moving the drone several seconds after the power on**. The drone calibrates its gyroscope on the start so it should stay still for a while.
-* **Check the IMU frequency**. Perform `imu` command. The `frequency` field should be about 1000 (Hz).
+* **Check the IMU sample rate**. Perform `imu` command. The `rate` field should be about 1000 (Hz).
 * **Check the IMU data**. Perform `imu` command, check raw accelerometer and gyro output. The output should change as you move the drone.
 * **Calibrate the accelerometer.** if is wasn't done before. Perform `ca` command and put the results to `imu.ino` file.
 * **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.

flix/cli.ino

@@ -53,7 +53,7 @@ const struct Param {
 	{"lpr", &ratesFilter.alpha, nullptr},
 	{"lpd", &rollRatePID.lpf.alpha, &pitchRatePID.lpf.alpha},
 
-	{"ss", &loopFreq, nullptr},
+	{"ss", &loopRate, nullptr},
 	{"dt", &dt, nullptr},
 	{"t", &t, nullptr},
 };
@@ -73,7 +73,7 @@ void doCommand(String& command, String& value) {
 		Serial.printf("gyro: %f %f %f\n", rates.x, rates.y, rates.z);
 		Serial.printf("acc: %f %f %f\n", acc.x, acc.y, acc.z);
 		printIMUCal();
-		Serial.printf("frequency: %f\n", loopFreq);
+		Serial.printf("rate: %f\n", loopRate);
 	} else if (command == "rc") {
 		Serial.printf("Raw: throttle %d yaw %d pitch %d roll %d armed %d mode %d\n",
 			channels[RC_CHANNEL_THROTTLE], channels[RC_CHANNEL_YAW], channels[RC_CHANNEL_PITCH],

flix/flix.ino

@@ -25,7 +25,7 @@
 
 float t = NAN; // current step time, s
 float dt; // time delta from previous step, s
-float loopFreq; // loop frequency, Hz
+float loopRate; // loop rate, Hz
 int16_t channels[RC_CHANNELS]; // raw rc channels
 float controls[RC_CHANNELS]; // normalized controls in range [-1..1] ([0..1] for throttle)
 float controlsTime; // time of the last controls update

flix/time.ino

@@ -12,16 +12,16 @@ void step() {
 		dt = 0; // assume dt to be zero on first step and on reset
 	}
 
-	computeLoopFreq();
+	computeLoopRate();
 }
 
-void computeLoopFreq() {
+void computeLoopRate() {
 	static float windowStart = 0;
-	static uint32_t freq = 0;
-	freq++;
+	static uint32_t rate = 0;
+	rate++;
 	if (t - windowStart >= 1) { // 1 second window
-		loopFreq = freq;
+		loopRate = rate;
 		windowStart = t;
-		freq = 0;
+		rate = 0;
 	}
 }

gazebo/flix.h

@@ -21,7 +21,7 @@
 
 float t = NAN;
 float dt;
-float loopFreq;
+float loopRate;
 float motors[4];
 int16_t channels[16]; // raw rc channels
 float controls[RC_CHANNELS];
@@ -32,7 +32,7 @@ Vector rates;
 Quaternion attitude;
 
 // declarations
-void computeLoopFreq();
+void computeLoopRate();
 void applyGyro();
 void applyAcc();
 void control();