/* counter_tcc.avr.c - Internal counter support. */ /* 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 "counter.h" #include "modules/utils/utils.h" #include "io.h" #include "misc.h" /** * This file add support for an AVR internal counter. This uses one TCC * hardware per counter, and an external circuitry to compute rotation * direction. */ /** Define to 1 to reverse the left counter. */ #define COUNTER_LEFT_REVERSE 0 /** Define to 1 to reverse the right counter. */ #define COUNTER_RIGHT_REVERSE 0 /** 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. */ uint16_t counter_left, counter_right; /** Counter differences since last update. * Maximum of 9 significant bits, sign included. */ int16_t counter_left_diff, counter_right_diff; /** Initialize the counters. */ 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_left_frw = 0; counter_left_rev = 0; counter_left_old = TCNT2; counter_right_frw = 0; counter_right_rev = 0; counter_right_old = TCNT3L; /* Interrupts for direction. */ EICRB = 0x05; EIFR = _BV (4) | _BV (5); EIMSK = _BV (4) | _BV (5); } /** Left direction change. */ SIGNAL (SIG_INTERRUPT4) { uint8_t c; c = TCNT2; if (PINE & _BV (4)) { counter_left_rev += c - counter_left_old; LED1 (!COUNTER_LEFT_REVERSE); } else { counter_left_frw += c - counter_left_old; LED1 (COUNTER_LEFT_REVERSE); } counter_left_old = c; } /** Right direction change. */ SIGNAL (SIG_INTERRUPT5) { uint8_t c; c = TCNT3L; if (PINE & _BV (5)) { counter_right_rev += c - counter_right_old; LED2 (!COUNTER_RIGHT_REVERSE); } else { counter_right_frw += c - counter_right_old; LED2 (COUNTER_RIGHT_REVERSE); } counter_right_old = c; } void counter_update_step (void) { /* No support for update steps. */ } /** Update overall counter values and compute diffs. */ void counter_update (void) { uint8_t c; /* Disable ints. */ EIMSK &= ~(_BV (4) | _BV (5)); /* Read left counter. */ c = TCNT2; if (PINE & _BV (4)) counter_left_frw += c - counter_left_old; else counter_left_rev += c - counter_left_old; counter_left_old = c; /* Read right counter. */ c = TCNT3L; if (PINE & _BV (5)) counter_right_frw += c - counter_right_old; else counter_right_rev += c - counter_right_old; counter_right_old = c; /* Update counter values and diffs. */ #if COUNTER_LEFT_REVERSE == 0 counter_left_diff = counter_left_frw; counter_left_diff -= counter_left_rev; #else counter_left_diff = counter_left_rev; counter_left_diff -= counter_left_frw; #endif counter_left_frw = 0; counter_left_rev = 0; counter_left += counter_left_diff; #if COUNTER_RIGHT_REVERSE == 0 counter_right_diff = counter_right_frw; counter_right_diff -= counter_right_rev; #else counter_right_diff = counter_right_rev; counter_right_diff -= counter_right_frw; #endif counter_right_frw = 0; counter_right_rev = 0; counter_right += counter_right_diff; /* Enable ints. */ EIMSK |= _BV (4) | _BV (5); }