🐛 Fix Global Gyro Constructors

Summary:
The delay in the `adi_gyro_init()` function called by the `pros::ADIGyro` ctor caused segfaults when creating
a gyro object globally, since the scheduler hasn't started at that point.

Closes T640.

Test Plan:
[x] Compiles
[x] Run test code with a global gyro ctor and observe if/when the VexOS delay happens.
Test code:
```
#include "main.h"

pros::ADIGyro global_gyro ('a');

void opcontrol() {
	while (true) {
		pros::lcd::print(1, "%f", global_gyro.get_value());

		pros::delay(20);
	}
}
```
This displays `-32768.000000` for the 1300ms calibration time, then starts properly printing. For now we should just include a warning about this to users and encourage them to declare gyroscopes in a local scope, but this could be a good application for something along the lines of T635.

Reviewers: O1 The Ori, berman5

Reviewed By: O1 The Ori, berman5

Subscribers: berman5

Tags: #zorp

Maniphest Tasks: T640

Differential Revision: https://phabricator.purduesigbots.com/D201

include/pros/adi.h

@@ -642,11 +642,11 @@ double adi_gyro_get(adi_gyro_t gyro);
 
 /**
  * Initializes a gyroscope on the given port. If the given port has not
- * previously been configured as a gyro, then this function starts a 1 second
+ * previously been configured as a gyro, then this function starts a 1300 ms
  * calibration period.
  *
- * If calibration is required, it is highly recommended that this function be
- * called from initialize when the robot is stationary.
+ * It is highly recommended that this function be called from initialize() when
+ * the robot is stationary to ensure proper calibration.
  *
  * This function uses the following values of errno when an error state is
  * reached:

include/pros/adi.hpp

@@ -476,11 +476,14 @@ class ADIGyro : private ADIPort {
 	public:
 	/**
 	 * Initializes a gyroscope on the given port. If the given port has not
-	 * previously been configured as a gyro, then this function starts a 1 second
+	 * previously been configured as a gyro, then this function starts a 1300ms
 	 * calibration period.
 	 *
-	 * If calibration is required, it is highly recommended that this function be
-	 * called from initialize when the robot is stationary.
+	 * It is highly recommended that an ADIGyro object be created in initialize()
+	 * when the robot is stationary to ensure proper calibration. If an ADIGyro
+	 * object is declared at the global scope, a hardcoded 1300ms delay at the
+	 * beginning of initialize will be necessary to ensure that the gyro's
+	 * returned values are correct at the beginning of autonomous/opcontrol.
 	 *
 	 * This function uses the following values of errno when an error state is
 	 * reached:

src/devices/vdml_adi.c

@@ -26,6 +26,10 @@
 
 #define NUM_MAX_TWOWIRE 4
 
+// Theoretical calibration time is 1024ms, but in practice this seemed to be the
+// actual time that it takes.
+#define GYRO_CALIBRATION_TIME 1300
+
 typedef union adi_data {
 	struct {
 		int32_t calib;
@@ -373,8 +377,12 @@ adi_gyro_t adi_gyro_init(uint8_t port, double multiplier) {
 	}
 
 	int status = _adi_port_set_config(port, E_ADI_LEGACY_GYRO);
-	delay(1300);  // Actual calibration time is 1024ms, but in practice this seemed
-	              // to be the bare minimum time it takes
+	if (xTaskGetSchedulerState() == taskSCHEDULER_RUNNING)
+		// If the scheduler is currently running (meaning that this is not called
+		// from a global constructor, for example) then delay for the duration of
+		// the calibration time in VexOS.
+		delay(GYRO_CALIBRATION_TIME);
+
 	if (status)
 		return port;
 	else