50 lines
1.1 KiB
C
50 lines
1.1 KiB
C
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#include <spi.h>
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#include <util/delay.h>
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void spi_initialize(spi_t *spi) {
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set_line_direction(&spi->clock, LINE_OUT);
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set_line_direction(&spi->data_out, LINE_OUT);
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set_line_direction(&spi->data_in, LINE_IN);
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set_line_direction(&spi->chip_select, LINE_OUT);
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set_line(&spi->chip_select);
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}
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void spi_acquire(spi_t *spi) {
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clear_line(&spi->chip_select);
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}
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void spi_release(spi_t *spi) {
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set_line(&spi->chip_select);
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}
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uint8_t spi_transfer_byte(spi_t *spi, uint8_t output) {
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uint8_t input = 0;
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// int input_bit;
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for (int i = 7; i >= 0; i--) {
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clear_line(&spi->clock);
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if (output & _BV(i)) {
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set_line(&spi->data_out);
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} else {
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clear_line(&spi->data_out);
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}
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_delay_us(10);
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set_line(&spi->clock);
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_delay_us(10);
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//input_bit = read_line(&spi->data_in);
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//input <<= input_bit;
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}
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clear_line(&spi->clock);
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_delay_us(10);
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return input;
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}
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/*
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void send_bytes(spi_t *line, u8 *byte, size_t length, u8 *input, size_t input_length) {
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}
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*/
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