AC_PID Library - added example sketch

libraries/AC_PID/examples/AC_PID_test/AC_PID_test.pde

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+/*
+	Example of PID library.
+	2012 Code by Jason Short, Randy Mackay. DIYDrones.com
+*/
+
+// includes
+#include <Arduino_Mega_ISR_Registry.h>
+#include <FastSerial.h>
+#include <AP_Common.h>
+#include <APM_RC.h> // ArduPilot RC Library
+#include <AC_PID.h> // ArduPilot Mega RC Library
+
+// default PID values
+#define TEST_P 1.0
+#define TEST_I 0.01
+#define TEST_D 0.2
+#define TEST_IMAX 10
+
+// Serial ports
+FastSerialPort0(Serial);        // FTDI/console
+
+// Global variables
+Arduino_Mega_ISR_Registry isr_registry;
+APM_RC_APM1 APM_RC;
+
+// setup function
+void setup()
+{
+	Serial.begin(115200);
+	Serial.println("ArduPilot Mega AC_PID library test");
+
+	isr_registry.init();
+	APM_RC.Init(&isr_registry);	 // APM Radio initialization
+
+	delay(1000);
+}
+
+// main loop
+void loop()
+{
+	// setup (unfortunately must be done here as we cannot create a global AC_PID object)
+	AC_PID pid(0, PSTR("TESTPID_"),  TEST_P, TEST_I, TEST_D, TEST_IMAX * 100);
+	uint16_t radio_in;
+	uint16_t radio_trim;
+	int error;
+	int control;
+	float dt = 1000/50;
+
+	// display PID gains
+	Serial.printf("P %f  I %f  D %f  imax %f\n", pid.kP(), pid.kI(), pid.kD(), pid.imax());
+
+	// capture radio trim
+	radio_trim = APM_RC.InputCh(0);
+
+	while( true ) {
+		radio_in = APM_RC.InputCh(0);
+		error = radio_in - radio_trim;
+		control = pid.get_pid(error, dt);
+
+		// display pid results
+		Serial.printf("radio: %d\t err: %d\t pid:%d\n", radio_in, error, control);
+		delay(50);
+	}
+}

libraries/AC_PID/examples/AC_PID_test/Makefile

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+BOARD	=	mega
+include ../../../AP_Common/Arduino.mk