diff options
Diffstat (limited to 'tube-rotator/stepper.c')
| -rw-r--r-- | tube-rotator/stepper.c | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/tube-rotator/stepper.c b/tube-rotator/stepper.c new file mode 100644 index 0000000..8b718ae --- /dev/null +++ b/tube-rotator/stepper.c @@ -0,0 +1,169 @@ +/* + * spreadspace avr utils + * + * + * Copyright (C) 2014 Christian Pointner <equinox@spreadspace.org> + * + * This file is part of spreadspace avr utils. + * + * spreadspace avr utils 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 3 of the License, or + * any later version. + * + * spreadspace avr utils 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 spreadspace avr utils. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <avr/sfr_defs.h> +#include <avr/interrupt.h> +#include <util/atomic.h> +#include <math.h> + +#include "stepper.h" + +uint8_t step_table [] = +{ + 2, // 0010 + 6, // 0110 + 4, // 0100 + 5, // 0101 + 1, // 0001 + 9, // 1001 + 8, // 1000 + 10, // 1010 +}; + +#define STEPPER_PORT PORTF +#define STEPPER_DDR DDRF +#define STEPPER_FIRST_BIT 4 +#define STEPPER_ENABLE_A_BIT 0 +#define STEPPER_ENABLE_B_BIT 1 +#define LENGTH_STEP_TABLE (sizeof(step_table)/sizeof(uint8_t)) +#define STEPPER_OUTPUT_BITMASK (~(0xF << STEPPER_FIRST_BIT )) + +volatile uint16_t target_speed; +uint16_t current_speed; +stepper_state_t current_state; + +void stepper_init(void) +{ + target_speed = STEPPER_SPEED_DEFAULT; + STEPPER_PORT &= ~(0xF << STEPPER_FIRST_BIT | 1<<STEPPER_ENABLE_A_BIT | 1<<STEPPER_ENABLE_B_BIT); + STEPPER_DDR |= (0xF << STEPPER_FIRST_BIT) | (1<<STEPPER_ENABLE_A_BIT) | (1<<STEPPER_ENABLE_B_BIT); + stepper_stop(); +} + +void stepper_start(void) +{ + if(current_state == stepper_running) return; + + current_speed = STEPPER_SPEED_MIN; + STEPPER_PORT |= (1<<STEPPER_ENABLE_A_BIT) | (1<<STEPPER_ENABLE_B_BIT); + TCNT1 = 0; + OCR1A = current_speed; + TCCR1A = 0; // prescaler 1:64, WGM = 4 (CTC) + TCCR1B = 1<<WGM12 | 1<<CS11 | 1<<CS10; // + TIMSK1 = 1<<OCIE1A; + current_state = stepper_running; +} + +void stepper_stop(void) +{ + STEPPER_PORT &= ~(0xF << STEPPER_FIRST_BIT | 1<<STEPPER_ENABLE_A_BIT | 1<<STEPPER_ENABLE_B_BIT); + TCCR1B = 0; // no clock source + TIMSK1 = 0; // disable timer interrupt + current_state = stepper_stopped; +} + +static inline void stepper_handle(void) +{ + static uint8_t step_idx = 0; + + uint8_t stepper_output = step_table[step_idx]; + stepper_output <<= STEPPER_FIRST_BIT; + STEPPER_PORT = (STEPPER_PORT & STEPPER_OUTPUT_BITMASK ) | stepper_output; + step_idx++; + step_idx %= LENGTH_STEP_TABLE; + + if(step_idx != 0 && step_idx % 8) { + if(current_speed > target_speed) + OCR1A = (uint16_t)((STEPPER_SPEED_CONVERT_VALUE/(--current_speed)) - 1); + else if(current_speed < target_speed) + OCR1A = (uint16_t)((STEPPER_SPEED_CONVERT_VALUE/(++current_speed)) - 1); + } +} + +ISR(TIMER1_COMPA_vect) +{ + stepper_handle(); +} + +stepper_state_t stepper_get_state(void) +{ + return current_state; +} + +const char* stepper_state_to_string(stepper_state_t state) +{ + switch(state) { + case stepper_running: return "running"; + case stepper_stopped: return "stopped"; + } + return "?"; +} + +void stepper_set_speed(uint16_t new_speed) +{ + if(new_speed >= STEPPER_SPEED_MIN && new_speed <= STEPPER_SPEED_MAX) { + ATOMIC_BLOCK(ATOMIC_RESTORESTATE) { + target_speed = new_speed; + } + } +} + +void stepper_inc_speed(void) +{ + ATOMIC_BLOCK(ATOMIC_RESTORESTATE) { + target_speed = (target_speed >= STEPPER_SPEED_MAX) ? STEPPER_SPEED_MAX : target_speed + 1; + } +} + +void stepper_dec_speed(void) +{ + ATOMIC_BLOCK(ATOMIC_RESTORESTATE) { + target_speed = (target_speed <= STEPPER_SPEED_MIN) ? STEPPER_SPEED_MIN : target_speed - 1; + } +} + +uint16_t stepper_get_speed(void) +{ + return target_speed; +} + +void stepper_set_speed_rpm(uint8_t new_rpm) +{ + stepper_set_speed( (uint16_t)lround( ( (double)(64.0 * 800.0 * (double)STEPPER_SPEED_CONVERT_VALUE) / (double)(60.0 * (double)F_CPU) ) * (double)new_rpm) ); +} + +uint8_t stepper_get_speed_rpm(void) +{ + return (uint8_t)lround( ( (double)(60.0 * (double)F_CPU) / (double)(64.0 * 800.0 * (double)STEPPER_SPEED_CONVERT_VALUE) ) * (double)(target_speed) ); +} + +void stepper_inc_speed_rpm(void) +{ + uint8_t rpm = stepper_get_speed_rpm(); + stepper_set_speed_rpm((rpm >= 255) ? 255 : rpm+1); +} + +void stepper_dec_speed_rpm(void) +{ + uint8_t rpm = stepper_get_speed_rpm(); + stepper_set_speed_rpm((rpm <= 1) ? 1 : rpm-1); +} |