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authorJérémy Dufour2008-03-19 11:33:37 +0100
committerJérémy Dufour2008-03-19 11:33:37 +0100
commit624f2f2aade9f87ff22f56e0b5a9999cdd1db458 (patch)
tree4b17cc2b018b577550b938a89904be2054548261 /digital/io/src/servo.h
parentfc4e130d5874a275db94719070d039b1913d8c57 (diff)
* digital/io/src
- add servo module (not integrated yet in the io program).
Diffstat (limited to 'digital/io/src/servo.h')
-rw-r--r--digital/io/src/servo.h85
1 files changed, 85 insertions, 0 deletions
diff --git a/digital/io/src/servo.h b/digital/io/src/servo.h
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+#ifndef servo_h
+#define servo_h
+/* servo.h */
+/* io - Input & Output with Artificial Intelligence (ai) support on AVR. {{{
+ *
+ * Copyright (C) 2008 Dufour Jrmy
+ *
+ * APBTeam:
+ * Web: http://apbteam.org/
+ * Email: team AT apbteam DOT org
+ *
+ * This program 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 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * }}} */
+
+#include "common.h" // uint8_t
+
+/**
+ * @file Module to control servo motors.
+ * This module contains low-level functions to control the servo motors. If
+ * you want to control the traps to store the balls at a specific place, have
+ * a look at the trap module.
+ * It uses the timer/counter 2 (8-bit).
+ *
+ * Servo motors can be controlled by the time the input signal spend at its
+ * high state. For example, if the signal sent to the servo motor only spend
+ * 0.5ms at the high state, it will have a 0 angle position. If the signal
+ * stays for 1.5ms at high state, it will have a 90 angle position.
+ * To manage all servo motors in a "one time shot", we need to use the
+ * timer/counter 2 of the ATmega128 and its overflow.
+ * We setup the timer/counter to the value of its overflow minus the time the
+ * input signal of the servo need to spend at high state ; we put the input
+ * signal of this servo motor to the high value. When the timer overflows, we
+ * put it back to the low state. We go to the next servo motors and do the
+ * same algorithm. When the all servos motor have been taken care of, we
+ * set-up the timer to overflow a certain number of times to wait before
+ * restarting the whole cycle.
+ */
+
+/**
+ * Number of servos motor managed by this module.
+ */
+#define SERVO_NUMBER 5
+
+/**
+ * Initialize servo module.
+ * This functions put the pins of the servos motor in the right direction,
+ * initialize the timer/counter 2 and some internals stuff.
+ * A important remark: you need to set the default values of each servos motor
+ * before calling this functions if you do not want to have some strange
+ * behavior.
+ */
+void
+servo_init (void);
+
+/**
+ * Set the high time of the input signal of a servo (and its position).
+ * @param servo the servo to change the position.
+ * @param high_time the high time we want the input signal to spend at the
+ * high state to set the servo motor to a position.
+ */
+void
+servo_set_high_time (uint8_t servo, uint8_t high_time);
+
+/**
+ * Get the high time of the servo.
+ * @param servo the servo to get the position of.
+ * @return the current position of the servo.
+ */
+uint8_t
+servo_get_high_time (uint8_t servo);
+
+#endif /* servo_h */