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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/timer.c
parent603d1062ef6decd1a3065a12efc8f12480edb71b (diff)
Importing files from n/asserv
Diffstat (limited to 'n/line-follower/src/timer.c')
-rw-r--r--n/line-follower/src/timer.c74
1 files changed, 74 insertions, 0 deletions
diff --git a/n/line-follower/src/timer.c b/n/line-follower/src/timer.c
new file mode 100644
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+++ b/n/line-follower/src/timer.c
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+/* timer.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.
+ *
+ * }}} */
+
+/* +AutoDec */
+
+/** Initialise the timer. */
+static inline void
+timer_init (void);
+
+/** Test if a overflow occured and reset the flag. */
+static inline int
+timer_pending (void);
+
+/** Read timer value. Used for performance analysis. */
+static inline int8_t
+timer_read (void);
+
+/* -AutoDec */
+
+/** Initialise the timer. */
+static inline void
+timer_init (void)
+{
+ /* 256 prescaler. */
+ TCCR0 = regv (FOC0, WGM00, COM01, COM0, WGM01, CS02, CS01, CS00,
+ 0, 0, 0, 0, 0, 1, 1, 0);
+ /* Fov = F_io / (prescaler * (TOP + 1))
+ * TOP = 0xff
+ * Tov = 1 / Fov = 4.44 ms */
+}
+
+/** Test if a overflow occured and reset the flag. */
+static inline int
+timer_pending (void)
+{
+ if (TIFR & _BV (TOV0))
+ {
+ /* Write 1 to clear. */
+ TIFR |= _BV (TOV0);
+ return 1;
+ }
+ else
+ return 0;
+}
+
+/** Read timer value. Used for performance analysis. */
+static inline int8_t
+timer_read (void)
+{
+ return TCNT0;
+}
+