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authorprot2004-12-09 23:57:42 +0000
committerprot2004-12-09 23:57:42 +0000
commit853fb5b5d899eb55f1f7d4044bff0a8d5d84b694 (patch)
treebe3ed35adefb3637e15963f70d12ce6402d35ccb /n/line-follower/src/counter.c
parent603d1062ef6decd1a3065a12efc8f12480edb71b (diff)
Importing files from n/asserv
Diffstat (limited to 'n/line-follower/src/counter.c')
-rw-r--r--n/line-follower/src/counter.c135
1 files changed, 135 insertions, 0 deletions
diff --git a/n/line-follower/src/counter.c b/n/line-follower/src/counter.c
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+/* counter.c */
+/* asserv - Position & speed motor control on a ATmega128. {{{
+ *
+ * Copyright (C) 2004 Nicolas Schodet
+ *
+ * Robot APB Team/Efrei 2005.
+ * Web: http://assos.efrei.fr/robot/
+ * Email: robot AT efrei DOT fr
+ *
+ * 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.
+ *
+ * }}} */
+
+/** Forward and reverse counter values. */
+static uint8_t counter_left_frw, counter_left_rev,
+ counter_right_frw, counter_right_rev;
+/** Last TCNT values. */
+static uint8_t counter_left_old, counter_right_old;
+/** Overall counter values. */
+static uint16_t counter_left, counter_right;
+/** Counter differences since last update.
+ * Maximum of 9 significant bits, sign included. */
+static int16_t counter_left_diff, counter_right_diff;
+
+/* +AutoDec */
+
+/** Initialize the counters. */
+static inline void
+counter_init (void);
+
+/** Poll counters, should be called as often as possible. */
+static inline void
+counter_poll (void);
+
+/** Update overall counter values and compute diffs. */
+static inline void
+counter_update (void);
+
+/** Restart counting. */
+static inline void
+counter_restart (void);
+
+/* -AutoDec */
+
+/** Initialize the counters. */
+static 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_restart ();
+}
+
+/** Poll counters, should be called as often as possible. */
+static inline void
+counter_poll (void)
+{
+ uint8_t c;
+ /* Read left counter. */
+ c = TCNT2;
+ if (PINE & _BV (4))
+ {
+ PORTD &= ~0x40;
+ counter_left_frw += c - counter_left_old;
+ }
+ else
+ {
+ PORTD |= 0x40;
+ counter_left_rev += c - counter_left_old;
+ }
+ counter_left_old = c;
+ /* Read right counter. */
+ c = TCNT3L;
+ if (PINE & _BV (5))
+ {
+ PORTD &= ~0x20;
+ counter_right_frw += c - counter_right_old;
+ }
+ else
+ {
+ PORTD |= 0x20;
+ counter_right_rev += c - counter_right_old;
+ }
+ counter_right_old = c;
+}
+
+/** Update overall counter values and compute diffs. */
+static inline void
+counter_update (void)
+{
+ counter_left_diff = counter_left_frw;
+ counter_left_frw = 0;
+ counter_left_diff -= counter_left_rev;
+ counter_left_rev = 0;
+ counter_left += counter_left_diff;
+ counter_right_diff = counter_right_frw;
+ counter_right_frw = 0;
+ counter_right_diff -= counter_right_rev;
+ counter_right_rev = 0;
+ counter_right += counter_right_diff;
+}
+
+/** Restart counting. */
+static inline void
+counter_restart (void)
+{
+ counter_left_frw = 0;
+ counter_left_rev = 0;
+ counter_left_old = TCNT2;
+ counter_right_frw = 0;
+ counter_right_rev = 0;
+ counter_right_old = TCNT3L;
+}
+