Revert t variable type to float instead of double

For the sake of simplicity and consistency.

docs/firmware.md

@@ -8,7 +8,7 @@ The firmware is a regular Arduino sketch, and it follows the classic Arduino one
 
 The main loop is running at 1000 Hz. All the dataflow goes through global variables (for simplicity):
 
-* `t` *(double)* — current step time, *s*.
+* `t` *(float)* — current step time, *s*.
 * `dt` *(float)* — time delta between the current and previous steps, *s*.
 * `gyro` *(Vector)* — data from the gyroscope, *rad/s*.
 * `acc` *(Vector)* — acceleration data from the accelerometer, *m/s<sup>2</sup>*.

flix/cli.ino

@@ -9,8 +9,7 @@
 
 extern const int MOTOR_REAR_LEFT, MOTOR_REAR_RIGHT, MOTOR_FRONT_RIGHT, MOTOR_FRONT_LEFT;
 extern const int ACRO, STAB, AUTO;
-extern float loopRate, dt;
-extern double t;
+extern float t, dt, loopRate;
 extern uint16_t channels[16];
 extern float controlRoll, controlPitch, controlThrottle, controlYaw, controlMode;
 extern int mode;
@@ -60,7 +59,7 @@ void print(const char* format, ...) {
 }
 
 void pause(float duration) {
-	double start = t;
+	float start = t;
 	while (t - start < duration) {
 		step();
 		handleInput();

flix/flix.ino

@@ -10,7 +10,7 @@
 #define SERIAL_BAUDRATE 115200
 #define WIFI_ENABLED 1
 
-double t = NAN; // current step time, s
+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;

flix/log.ino

@@ -10,7 +10,6 @@
 #define LOG_PERIOD 1.0 / LOG_RATE
 #define LOG_SIZE LOG_DURATION * LOG_RATE
 
-float tFloat;
 Vector attitudeEuler;
 Vector attitudeTargetEuler;
 
@@ -20,7 +19,7 @@ struct LogEntry {
 };
 
 LogEntry logEntries[] = {
-	{"t", &tFloat},
+	{"t", &t},
 	{"rates.x", &rates.x},
 	{"rates.y", &rates.y},
 	{"rates.z", &rates.z},
@@ -40,7 +39,6 @@ const int logColumns = sizeof(logEntries) / sizeof(logEntries[0]);
 float logBuffer[LOG_SIZE][logColumns];
 
 void prepareLogData() {
-	tFloat = t;
 	attitudeEuler = attitude.toEuler();
 	attitudeTargetEuler = attitudeTarget.toEuler();
 }
@@ -48,7 +46,7 @@ void prepareLogData() {
 void logData() {
 	if (!armed) return;
 	static int logPointer = 0;
-	static double logTime = 0;
+	static float logTime = 0;
 	if (t - logTime < LOG_PERIOD) return;
 	logTime = t;
 

flix/mavlink.ino

@@ -15,7 +15,7 @@
 bool mavlinkConnected = false;
 String mavlinkPrintBuffer;
 
-extern double controlTime;
+extern float controlTime;
 extern float controlRoll, controlPitch, controlThrottle, controlYaw, controlMode;
 
 void processMavlink() {
@@ -26,8 +26,8 @@ void processMavlink() {
 void sendMavlink() {
 	sendMavlinkPrint();
 
-	static double lastSlow = 0;
-	static double lastFast = 0;
+	static float lastSlow = 0;
+	static float lastFast = 0;
 
 	mavlink_message_t msg;
 	uint32_t time = t * 1000;

flix/parameters.ino

@@ -119,7 +119,7 @@ bool setParameter(const char *name, const float value) {
 }
 
 void syncParameters() {
-	static double lastSync = 0;
+	static float lastSync = 0;
 	if (t - lastSync < 1) return; // sync once per second
 	if (motorsActive()) return; // don't use flash while flying, it may cause a delay
 	lastSync = t;

flix/rc.ino

@@ -9,7 +9,7 @@
 SBUS rc(Serial2); // NOTE: Use RC(Serial2, 16, 17) if you use the old UART2 pins
 
 uint16_t channels[16]; // raw rc channels
-double controlTime; // time of the last controls update
+float controlTime; // time of the last controls update
 float channelZero[16]; // calibration zero values
 float channelMax[16]; // calibration max values
 

flix/safety.ino

@@ -6,7 +6,7 @@
 #define RC_LOSS_TIMEOUT 1
 #define DESCEND_TIME 10
 
-extern double controlTime;
+extern float controlTime;
 extern float controlRoll, controlPitch, controlThrottle, controlYaw;
 
 void failsafe() {

flix/time.ino

@@ -6,7 +6,7 @@
 float loopRate; // Hz
 
 void step() {
-	double now = micros() / 1000000.0;
+	float now = micros() / 1000000.0;
 	dt = now - t;
 	t = now;
 
@@ -18,7 +18,7 @@ void step() {
 }
 
 void computeLoopRate() {
-	static double windowStart = 0;
+	static float windowStart = 0;
 	static uint32_t rate = 0;
 	rate++;
 	if (t - windowStart >= 1) { // 1 second window

flix/util.h

@@ -10,7 +10,7 @@
 #include <soc/rtc_cntl_reg.h>
 
 const float ONE_G = 9.80665;
-extern double t;
+extern float t;
 
 float mapf(long x, long in_min, long in_max, float out_min, float out_max) {
 	return (float)(x - in_min) * (out_max - out_min) / (float)(in_max - in_min) + out_min;

gazebo/flix.h

@@ -12,7 +12,7 @@
 
 #define WIFI_ENABLED 1
 
-double t = NAN;
+float t = NAN;
 float dt;
 float motors[4];
 float controlRoll, controlPitch, controlYaw, controlThrottle = NAN;