/* pwm_ocr.avr.c - PWM using internal generator. */ /* asserv - Position & speed motor control on AVR. {{{ * * Copyright (C) 2008 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 "pwm_ocr.avr.h" #include "pwm.h" #include "modules/utils/utils.h" #include "io.h" /** Assign PWM outputs. */ #define PWM1 pwm_aux0 #define PWM2 pwm_aux1 #define PWM1_OCR OCR1A #define PWM1_OCR_BIT 5 #define PWM1_DIR 3 #define PWM2_OCR OCR1B #define PWM2_OCR_BIT 4 #define PWM2_DIR 2 #define PWM1_BRK_IO A, 4 #define PWM2_BRK_IO A, 5 #include "pwm_config.h" /** PWM reverse direction, port D. */ static uint8_t pwm_ocr_dir_reverse_d; /** Initialise PWM generator. */ void pwm_ocr_init (void) { /* Phase Correct PWM, TOP = 0x3ff, OCnA & OCnB with positive logic. * f_IO without prescaler. * Fpwm = f_IO / (2 * prescaler * (1 + TOP)) = 7200 Hz. */ #if PWM1or2 TCCR1A = regv (COM1A1, COM1A0, COM1B1, COM1B0, FOC1A, FOC1B, WGM11, WGM10, 1, 0, 1, 0, 0, 0, 1, 1); TCCR1B = regv (ICNC1, ICES1, 5, WGM13, WGM12, CS12, CS11, CS10, 0, 0, 0, 0, 0, 0, 0, 1); /* Enable PWM and direction outputs in DDRD. */ DDRD |= PWM1c (_BV (PWM1_OCR_BIT) | _BV (PWM1_DIR)) | PWM2c (_BV (PWM2_OCR_BIT) | _BV (PWM2_DIR)); /* Will activate output at first non zero PWM. */ # ifdef PWM1 IO_OUTPUT (PWM1_BRK_IO); # endif # ifdef PWM2 IO_OUTPUT (PWM2_BRK_IO); # endif #endif } /** Update the hardware PWM values. */ void pwm_ocr_update (void) { #if PWM1or2 uint8_t dir_d; /* Sample port D. */ dir_d = PORTD & ~(PWM1c (_BV (PWM1_DIR)) | PWM2c (_BV (PWM2_DIR))); # ifdef PWM1 uint16_t pwm1; /* Set PWM1. */ if (PWM_VALUE (PWM1) == 0) { pwm1 = 0; } else { IO_SET (PWM1_BRK_IO); if (PWM_VALUE (PWM1) < 0) { pwm1 = -PWM_VALUE (PWM1); } else { dir_d |= _BV (PWM1_DIR); pwm1 = PWM_VALUE (PWM1); } } # endif /* PWM1 */ # ifdef PWM2 uint16_t pwm2; /* Set PWM2. */ if (PWM_VALUE (PWM2) == 0) { pwm2 = 0; } else { IO_SET (PWM2_BRK_IO); if (PWM_VALUE (PWM2) < 0) { pwm2 = -PWM_VALUE (PWM2); } else { dir_d |= _BV (PWM2_DIR); pwm2 = PWM_VALUE (PWM2); } } # endif /* PWM2 */ #endif /* PWM1or2 */ /* Setup registers. */ /* Here, there could be a problem because OCRx are double buffered, not * PORTx! */ /* Another problem arise if the OCR sampling is done between left and * right OCR: the right PWM is one cycle late. */ /* A solution could be to use interrupts to update PWM or to synchronise * general timer with PWM. */ #if PWM1or2 dir_d ^= pwm_ocr_dir_reverse_d; PORTD = dir_d; # ifdef PWM1 PWM1_OCR = pwm1; # endif # ifdef PWM2 PWM2_OCR = pwm2; # endif #endif /* PWM1or2 */ } void pwm_ocr_set_reverse (uint8_t reverse) { pwm_reverse = reverse; pwm_ocr_dir_reverse_d = 0; #ifdef PWM1 if (reverse & PWM_REVERSE_BIT (PWM1)) pwm_ocr_dir_reverse_d |= _BV (PWM1_DIR); #endif #ifdef PWM2 if (reverse & PWM_REVERSE_BIT (PWM2)) pwm_ocr_dir_reverse_d |= _BV (PWM2_DIR); #endif }