From 872dfd49752b0fe5b7d4e8588c0abaac3829b7dc Mon Sep 17 00:00:00 2001 From: Nicolas Schodet Date: Fri, 6 Apr 2012 23:20:37 +0200 Subject: digital/mimot: add asserv based program without aux motors --- digital/mimot/src/asserv/timer.avr.c | 68 ++++++++++++++++++++++++++++++++++++ 1 file changed, 68 insertions(+) create mode 100644 digital/mimot/src/asserv/timer.avr.c (limited to 'digital/mimot/src/asserv/timer.avr.c') diff --git a/digital/mimot/src/asserv/timer.avr.c b/digital/mimot/src/asserv/timer.avr.c new file mode 100644 index 00000000..45079ccd --- /dev/null +++ b/digital/mimot/src/asserv/timer.avr.c @@ -0,0 +1,68 @@ +/* timer.avr.c */ +/* asserv - Position & speed motor control on AVR. {{{ + * + * Copyright (C) 2005 Nicolas Schodet + * + * 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" + +#include "modules/utils/utils.h" +#include "modules/motor/encoder/encoder.h" +#include "io.h" + +/** Top timer value. */ +#define TIMER_TOP 255 +/** Number of steps during wait. */ +#define TIMER_STEPS 4 +/** Size of step. */ +#define TIMER_STEP ((TIMER_TOP + 1) / TIMER_STEPS) + +/** Initialise the timer. */ +void +timer_init (void) +{ + TCCR0 = regv (FOC0, WGM00, COM01, COM00, WGM01, CS02, CS01, CS00, + 0, 0, 0, 0, 0, 1, 0, 0); + /* Fov = F_io / (prescaler * (TOP + 1)) + * TOP = 0xff + * prescaler = 256 + * Tov = 1 / Fov = 4.444 ms */ +} + +/** Wait for timer overflow. */ +void +timer_wait (void) +{ + uint8_t i; + /* Make small steps with counter updates. */ + for (i = 1; i < TIMER_STEPS; i++) + { + while (TCNT0 < i * TIMER_STEP) + ; + encoder_update_step (); + } + /* Wait overflow. */ + while (!(TIFR & _BV (TOV0))) + ; + /* Write 1 to clear. */ + TIFR = _BV (TOV0); +} + -- cgit v1.2.3