/* pwm.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 "pwm.h" #include "modules/utils/utils.h" #include "io.h" /** Assign PWM outputs. */ #define PWM1 pwm_left #define PWM2 pwm_right #define PWM3 pwm_aux0 #undef PWM4 #define PWM_REVERSE_BIT(x) PWM_REVERSE_BIT_ (x) #define PWM_REVERSE_BIT_(x) PWM_REVERSE_BIT_ ## x #define PWM_REVERSE_BIT_pwm_left _BV (0) #define PWM_REVERSE_BIT_pwm_right _BV (1) #define PWM_REVERSE_BIT_pwm_aux0 _BV (2) #define PWM1_OCR OCR1B #define PWM1_OCR_BIT 6 #define PWM1_DIR 4 #define PWM2_OCR OCR1C #define PWM2_OCR_BIT 7 #define PWM2_DIR 5 #define PWM3_OCR OCR3B #define PWM3_OCR_BIT 4 #define PWM3_DIR 2 #define PWM4_OCR OCR3C #define PWM4_OCR_BIT 5 #define PWM4_DIR 3 /* Simplify conditionnal compilation. */ #define PWM1or2 (defined (PWM1) || defined (PWM2)) #define PWM3or4 (defined (PWM3) || defined (PWM4)) #ifdef PWM1 # define PWM1c(x) x #else # define PWM1c(x) 0 #endif #ifdef PWM2 # define PWM2c(x) x #else # define PWM2c(x) 0 #endif #ifdef PWM3 # define PWM3c(x) x #else # define PWM3c(x) 0 #endif #ifdef PWM4 # define PWM4c(x) x #else # define PWM4c(x) 0 #endif /** PWM values, this is an error if absolute value is greater than the * maximum. */ int16_t pwm_left, pwm_right, pwm_aux0; /** PWM reverse directions. */ uint8_t pwm_reverse; /** PWM reverse direction, port B. */ static uint8_t pwm_dir_reverse_b; /** PWM reverse direction, port E. */ static uint8_t pwm_dir_reverse_e; /** Initialise PWM generator. */ void pwm_init (void) { /* Fast PWM, TOP = 0x3ff, OCnB & OCnC with positive logic. f_IO without prescaler. Fpwm = f_IO / (prescaler * (1 + TOP)) = 14400 Hz. */ #if PWM1or2 TCCR1A = regv (COM1A1, COM1A0, COM1B1, COM1B0, COM1C1, COM1C0, WGM11, WGM10, 0, 0, 1, 0, 1, 0, 1, 1); TCCR1B = regv (ICNC1, ICES1, 5, WGM13, WGM12, CS12, CS11, CS10, 0, 0, 0, 0, 1, 0, 0, 1); /* Enable pwm and direction outputs in DDRB. */ DDRB |= PWM1c (_BV (PWM1_OCR_BIT) | _BV (PWM1_DIR)) | PWM2c (_BV (PWM2_OCR_BIT) | _BV (PWM2_DIR)); #endif #if PWM3or4 TCCR3A = regv (COM3A1, COM3A0, COM3B1, COM3B0, COM3C1, COM3C0, WGM31, WGM30, 0, 0, 1, 0, 1, 0, 1, 1); TCCR3B = regv (ICNC3, ICES3, 5, WGM33, WGM32, CS32, CS31, CS30, 0, 0, 0, 0, 1, 0, 0, 1); /* Enable pwm and direction outputs in DDRE. */ DDRE |= PWM3c (_BV (PWM3_OCR_BIT) | _BV (PWM3_DIR)) | PWM4c (_BV (PWM4_OCR_BIT) | _BV (PWM4_DIR)); #endif } /** Update the hardware PWM values. */ void pwm_update (void) { /* Some assumption checks. */ assert (!PWM1c (PWM1 < -PWM_MAX || PWM1 > PWM_MAX)); assert (!PWM2c (PWM2 < -PWM_MAX || PWM2 > PWM_MAX)); assert (!PWM3c (PWM3 < -PWM_MAX || PWM3 > PWM_MAX)); assert (!PWM4c (PWM4 < -PWM_MAX || PWM4 > PWM_MAX)); #if PWM1or2 uint8_t dir_b; /* Sample port B. */ dir_b = PORTB & ~(PWM1c (_BV (PWM1_DIR)) | PWM2c (_BV (PWM2_DIR))); # ifdef PWM1 uint16_t pwm1; /* Set PWM1. */ if (PWM1 == 0) { pwm1 = 0; } else if (PWM1 < 0) { pwm1 = -PWM1; } else { dir_b |= _BV (PWM1_DIR); pwm1 = PWM1; } # endif /* PWM1 */ # ifdef PWM2 uint16_t pwm2; /* Set PWM2. */ if (PWM2 == 0) { pwm2 = 0; } else if (PWM2 < 0) { pwm2 = -PWM2; } else { dir_b |= _BV (PWM2_DIR); pwm2 = PWM2; } # endif /* PWM2 */ #endif /* PWM1or2 */ #if PWM3or4 uint8_t dir_e; /* Sample port E. */ dir_e = PORTE & ~(PWM3c (_BV (PWM3_DIR)) | PWM4c (_BV (PWM4_DIR))); # ifdef PWM3 uint16_t pwm3; /* Set PWM3. */ if (PWM3 == 0) { pwm3 = 0; } else if (PWM3 < 0) { pwm3 = -PWM3; } else { dir_e |= _BV (PWM3_DIR); pwm3 = PWM3; } # endif /* PWM3 */ # ifdef PWM4 uint16_t pwm4; /* Set PWM4. */ if (PWM4 == 0) { pwm4 = 0; } else if (PWM4 < 0) { pwm4 = -PWM4; } else { dir_e |= _BV (PWM4_DIR); pwm4 = PWM4; } # endif /* PWM4 */ #endif /* PWM3or4 */ /* 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_b ^= pwm_dir_reverse_b; PORTB = dir_b; # ifdef PWM1 PWM1_OCR = pwm1; # endif # ifdef PWM2 PWM2_OCR = pwm2; # endif #endif /* PWM1or2 */ #if PWM3or4 dir_e ^= pwm_dir_reverse_e; PORTE = dir_e; # ifdef PWM3 PWM3_OCR = pwm3; # endif # ifdef PWM4 PWM4_OCR = pwm4; # endif #endif /* PWM3or4 */ } void pwm_set_reverse (uint8_t reverse) { pwm_reverse = reverse; pwm_dir_reverse_b = 0; pwm_dir_reverse_e = 0; #ifdef PWM1 if (reverse & PWM_REVERSE_BIT (PWM1)) pwm_dir_reverse_b |= _BV (PWM1_DIR); #endif #ifdef PWM2 if (reverse & PWM_REVERSE_BIT (PWM2)) pwm_dir_reverse_b |= _BV (PWM2_DIR); #endif #ifdef PWM3 if (reverse & PWM_REVERSE_BIT (PWM3)) pwm_dir_reverse_e |= _BV (PWM3_DIR); #endif #ifdef PWM4 if (reverse & PWM_REVERSE_BIT (PWM4)) pwm_dir_reverse_e |= _BV (PWM4_DIR); #endif }