Module with servo tester function (#2001)

useful for identifying the response of a servo

conf/modules/servo_tester.xml

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+<!DOCTYPE module SYSTEM "module.dtd">
+
+<module name="servo_tester" dir="servo_tester">
+  <doc>
+    <description>
+      Servo tester
+      Has a setting to change the input to the servo in millisecond units.
+
+      You have to give the servo you want to test the name SERVO_TEST, and don't use
+      it in the command laws.
+
+      Additionally, you can make the servo do a series of step maneuvers, with increasing
+      amplitude. Tip: Open up the servo and measure the voltage on the potmeter with
+      a high speed recorder device (like a saleae Logic analyzer with analog inputs). This 
+      will let you model the response of the servo.
+    </description>
+    <define name="TIME_PER_DEFLECTION" value="0.8" description="Time between servo steps for the 'servo_run' feature"/>
+  </doc>
+  <settings>
+    <dl_settings NAME="Servo test">
+      <dl_settings NAME="Servo tester">
+        <dl_setting var="servo_test_val" min="1000" step="1" max="2000" module="modules/servo_tester/servo_tester" shortname="servo_input"/>
+        <dl_setting var="do_servo_run" min="0" step="1" max="1" module="modules/servo_tester/servo_tester" values="Off|On" shortname="servo_run"/>
+      </dl_settings>
+    </dl_settings>
+  </settings>
+  <header>
+    <file name="servo_tester.h"/>
+  </header>
+  <init fun="servo_tester_init()"/>
+  <periodic fun="servo_tester_periodic()" freq="512"/>
+  <makefile>
+    <file name="servo_tester.c"/>
+  </makefile>
+</module>
+

sw/airborne/modules/servo_tester/servo_tester.c

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+/*
+ * Copyright (C) 2012 Ewoud Smeur <ewoud_smeur@msn.com>
+ *
+ * This file is part of paparazzi.
+ *
+ * paparazzi is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * paparazzi is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with paparazzi; see the file COPYING.  If not, write to
+ * the Free Software Foundation, 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+/** @file modules/servo_tester/servo_tester.c
+ * Module that has a setting to change the input to a servo
+ * Call the servo that you want to test SERVO_TEST,
+ * and don't use it with the command laws
+ */
+
+#include "servo_tester.h"
+#include "subsystems/commands.h"
+#include "generated/airframe.h"
+#include "generated/airframe.h"
+#include "subsystems/actuators.h"
+
+int32_t servo_test_val;
+
+bool do_servo_run;
+int32_t servo_run_counter;
+int32_t servo_run_timer;
+int32_t servo_run_step;
+
+#ifndef TIME_PER_DEFLECTION
+/** Time in seconds per deflection, before going to the next */
+#define TIME_PER_DEFLECTION 0.8
+#endif
+
+int32_t servo_mean;
+
+void servo_tester_init()
+{
+  servo_test_val = SERVO_SERVO_TEST_NEUTRAL;
+  do_servo_run = false;
+  servo_run_counter = 0;
+  servo_run_timer = 0;
+  servo_run_step = (SERVO_SERVO_TEST_MAX - SERVO_SERVO_TEST_MIN) / 2 / 8;
+
+  servo_mean = SERVO_SERVO_TEST_NEUTRAL;
+}
+
+
+void servo_tester_periodic()
+{
+
+  /*Go up and down with increasing amplitude*/
+  if (do_servo_run && (servo_run_counter < 8)) {
+    servo_test_val = servo_mean + servo_run_counter * servo_run_step * ((servo_run_counter % 2) * 2 - 1);
+    servo_run_timer += 1;
+
+    /*Give time to reach the setpoint*/
+    if (servo_run_timer > (TIME_PER_DEFLECTION*SERVO_TESTER_PERIODIC_FREQ)) {
+      servo_run_timer = 0;
+      servo_run_counter += 1;
+    }
+  } else if (do_servo_run == true) {
+    /*Reset de servo run*/
+    do_servo_run = false;
+    servo_run_counter = 0;
+    servo_test_val = servo_mean;
+  }
+
+  Bound(servo_test_val, SERVO_SERVO_TEST_MIN, SERVO_SERVO_TEST_MAX);
+  Set_SERVO_TEST_Servo(servo_test_val);
+}
+

sw/airborne/modules/servo_tester/servo_tester.h

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+/*
+ * Copyright (C) 2012 Ewoud Smeur <ewoud_smeur@msn.com>
+ *
+ * This file is part of paparazzi.
+ *
+ * paparazzi is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * paparazzi is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with paparazzi; see the file COPYING.  If not, write to
+ * the Free Software Foundation, 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+/** @file modules/servo_tester/servo_tester.h
+ *
+ * Module useful for testing a servo and finding the response
+ */
+
+#ifndef SERVO_TESTER_H
+#define SERVO_TESTER_H
+
+#include "generated/airframe.h"
+
+extern int32_t servo_test_val;
+extern bool do_servo_run;
+
+void servo_tester_init(void);
+void servo_tester_periodic(void);
+
+#endif /* SERVO_TESTER_H */