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authorschodet2004-09-29 21:07:25 +0000
committerschodet2004-09-29 21:07:25 +0000
commit55b33a20a69479219745172575c4504acd52730d (patch)
tree64f847e19e623c32ed37f7429252c4e71034e013 /n/asserv/src/counter.c
parentce1909a893f3a4c799eb2f876b78cfb0cf16cbf6 (diff)
Initial revision
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diff --git a/n/asserv/src/counter.c b/n/asserv/src/counter.c
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+/* counter.c */
+/* {{{
+ *
+ * Copyright (C) 2004 Nicolas Schodet
+ *
+ * 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.
+ *
+ * Contact :
+ * Web: http://perso.efrei.fr/~schodet/
+ * Email: <contact@ni.fr.eu.org>
+ * }}} */
+#include "counter.h"
+#include <n/avr/utils/utils.h>
+
+/* +AutoDec */
+/* -AutoDec */
+
+/** Forward and reverse counter value. */
+static uint8_t counter_l_frw, counter_l_rev, counter_r_frw, counter_r_rev;
+/** Last TCNT value. */
+static uint8_t counter_l_old, counter_r_old;
+
+/** Initialize the counters. */
+inline void
+counter_init (void)
+{
+ /* Left counter. */
+ /* External, rising edge. */
+ TCCR2 = regv (FOC2, WGM20, COM21, COM20, WGM21, CS22, CS21, CS20,
+ 0, 0, 0, 0, 0, 1, 1, 1);
+ /* Right counter. */
+ /* Normal counter. */
+ //TCCR3A = 0;
+ /* External, rising edge. */
+ TCCR3B = regv (ICNC3, ICES3, 5, WGM33, WGM32, CS32, CS31, CS30,
+ 0, 0, 0, 0, 0, 1, 1, 1);
+ /* Begin with safe values. */
+ counter_reset ();
+}
+
+/* Update counter, should be called as often as possible. */
+inline void
+counter_update (void)
+{
+ uint8_t c;
+ /* Update left counter. */
+ c = TCNT2;
+ if (PINE & _BV (4))
+ {
+ PORTD &= ~0x40;
+ counter_l_frw += c - counter_l_old;
+ }
+ else
+ {
+ PORTD |= 0x40;
+ counter_l_rev += c - counter_l_old;
+ }
+ counter_l_old = c;
+ /* Update right counter. */
+ c = TCNT3L;
+ if (PINE & _BV (5))
+ {
+ PORTD &= ~0x20;
+ counter_r_frw += c - counter_r_old;
+ }
+ else
+ {
+ PORTD |= 0x20;
+ counter_r_rev += c - counter_r_old;
+ }
+ counter_r_old = c;
+}
+
+/* Reset the counters. */
+inline void
+counter_reset (void)
+{
+ counter_l_frw = 0;
+ counter_l_rev = 0;
+ counter_l_old = TCNT2;
+ counter_r_frw = 0;
+ counter_r_rev = 0;
+ counter_r_old = TCNT3L;
+}
+