/* pwm_mp.avr.c - PWM to be used with motor-power-avr. */ /* 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_mp.avr.h" #include "pwm.h" #include "modules/spi/spi.h" #include "modules/utils/utils.h" #include "io.h" /** Assign PWM outputs. */ #define PWM1 pwm_left #define PWM2 pwm_right #undef PWM3 #undef PWM4 #include "pwm_config.h" /** When true, start transmission. */ uint8_t pwm_mp_go; /** Initialise communication with motor-power-avr. */ void pwm_mp_init (void) { #if PWM3or4 /* Only needed for PWM3 and 4 because it is done in spi_init for SS (port * B0). */ PORTD |= _BV (4); DDRD |= _BV (4); #endif #if PWM1or2 || PWM3or4 spi_init (SPI_IT_DISABLE | SPI_ENABLE | SPI_MSB_FIRST | SPI_MASTER | SPI_CPOL_FALLING | SPI_CPHA_SETUP | SPI_FOSC_DIV16); #endif /* Reset PWM values at reset. */ pwm_mp_go = 1; pwm_mp_update (); pwm_mp_go = 0; } #if PWM1or2 || PWM3or4 /** Send command using SPI. */ static void pwm_mp_send (int16_t pwm1, int16_t pwm2) { uint8_t v; uint8_t cks; /* Convert to 12 bits. */ int16_t pwm1c = pwm1 << 1; int16_t pwm2c = pwm2 << 1; if (UTILS_ABS (pwm1c) < 0x10) pwm1c = 0; if (UTILS_ABS (pwm2c) < 0x10) pwm2c = 0; /* Send, computing checksum on the way. */ cks = 0x42; v = ((pwm1c >> 4) & 0xf0) | ((pwm2c >> 8) & 0x0f); spi_send (v); cks ^= v; v = pwm1c; spi_send (v); cks ^= v; v = pwm2c; spi_send (v); cks ^= v; spi_send (cks); } #endif /* PWM1or2 || PWM3or4 */ /** Update PWM values. */ void pwm_mp_update (void) { #if PWM1or2 || PWM3or4 if (PWM1c (PWM1) || PWM2c (PWM2) || PWM3c (PWM3) || PWM4c (PWM4)) pwm_mp_go = 1; if (!pwm_mp_go) return; #endif #if PWM1or2 /* Chip enable. */ PORTB &= ~_BV (0); pwm_mp_send (PWM1c (PWM1), PWM2c (PWM2)); /* Chip disable. */ PORTB |= _BV (0); #endif #if PWM3or4 /* Chip enable. */ PORTE &= ~_BV (4); pwm_mp_send (PWM3c (PWM3), PWM4c (PWM4)); /* Chip disable. */ PORTE |= _BV (4); #endif }