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93 lines
2.3 KiB
93 lines
2.3 KiB
6 years ago
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// Created by MightyPork on 2018/02/01.
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//
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#ifndef OW_SEARCH_H
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#define OW_SEARCH_H
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// --------------------------------------------------------------------------------------
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// External API functions for interfacing the bus
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// Customize as needed (and also update calls in the search function)
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/**
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* Reset the 1-wire bus
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*
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* @return presence pulse received
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*/
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extern bool ow_reset(void);
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/**
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* Write a byte to the bus
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*
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* @param[in] value byte value
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*/
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extern void ow_write_u8(uint8_t value);
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/**
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* Write a bit to the 1-wire bus
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*
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* @param[in] value bit value
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*/
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extern void ow_write_bit(bool value);
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/**
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* Read a bit from the 1-wire bus
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*
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* @return bit value
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*/
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extern bool ow_read_bit(void);
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// --------------------------------------------------------------------------------------
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/** Data type holding one romcode */
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typedef uint8_t ow_romcode_t[8];
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/** Get a bit from a romcode */
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#define ow_code_getbit(code, index) (bool)((code)[(index) / 8] & (1 << ((index) % 8)))
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/** Set a bit to 1 in a romcode */
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#define ow_code_setbit(code, index) ((code)[(index) / 8] |= (1 << ((index) % 8)))
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/**
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* States of the search algorithm
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*/
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enum ow_search_result {
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OW_SEARCH_DONE = 0,
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OW_SEARCH_MORE = 1,
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OW_SEARCH_FAILED = 2,
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};
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/**
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* Internal state of the search algorithm.
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* Check status to see if more remain to be read or an error occurred.
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*/
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struct ow_search_state {
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int8_t prev_last_fork;
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ow_romcode_t prev_code;
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uint8_t command;
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enum ow_search_result status;
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bool first;
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};
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/**
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* Init the state search struct
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*
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* @param[out] state - inited struct
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* @param[in] command - command to send for requesting the search (e.g. SEARCH_ROM)
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*/
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void ow_search_init(struct ow_search_state *state, uint8_t command);
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/**
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* Perform a search of the 1-wire bus, with a state struct pre-inited
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* using ow_search_init().
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*
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* Romcodes are stored in the byte arrays in a numerically ascending order.
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*
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* @param[in,out] state - search state, used for multiple calls with limited buffer size
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* @param[out] codes - buffer for found romcodes
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* @param[in] capacity - buffer capacity
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* @return number of romcodes found. Search status is stored in state->status
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*/
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uint16_t ow_search_run(struct ow_search_state *state, ow_romcode_t *codes, uint16_t capacity);
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#endif //OW_SEARCH_H
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