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Diffstat (limited to 'tube-rotator/stepper.c')
-rw-r--r-- | tube-rotator/stepper.c | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/tube-rotator/stepper.c b/tube-rotator/stepper.c new file mode 100644 index 0000000..1bb9cae --- /dev/null +++ b/tube-rotator/stepper.c @@ -0,0 +1,92 @@ +/* + * 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 "stepper.h" + +uint8_t step_table [] = +{ + /* full steps */ + /* 6, // 0110 */ + /* 5, // 0101 */ + /* 9, // 1001 */ + /* 10, // 1010 */ + + /* half steps */ + 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 )) + +void stepper_init(void) +{ + 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); +} + +void stepper_start(void) +{ + STEPPER_PORT |= (1<<STEPPER_ENABLE_A_BIT) | (1<<STEPPER_ENABLE_B_BIT); + TCCR1A = 0; // prescaler 1:256, WGM = 4 (CTC) + TCCR1B = 1<<WGM12 | 1<<CS12; // + OCR1A = 150; + TCNT1 = 0; + TIMSK1 = 1<<OCIE1A; +} + +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 +} + +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; +} + +ISR(TIMER1_COMPA_vect) +{ + stepper_handle(); +} |