Revision 168:bfc84ee2839b analog_exp/onewire.c
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#include <string.h> |
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#include "debug.h" |
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#include "onewire_hal.h" |
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#include "onewire.h" |
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} |
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} |
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uint8_t onewire_rx_byte(uint8_t data) {
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uint8_t onewire_rx_byte(void) {
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uint8_t data = 0; |
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for(uint8_t i=0; i<8; i++) {
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data >>= 1; |
| ... | ... | |
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} |
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void onewire_readrom(onewire_id id) {
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onewire_reset(); |
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onewire_tx_byte(ONEWIRE_CMD_READROM); |
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for(uint8_t i=0; i<8; i++) {
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id[i] = onewire_rx_byte(); |
| ... | ... | |
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} |
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void onewire_matchrom(onewire_id id) {
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onewire_reset(); |
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onewire_tx_byte(ONEWIRE_CMD_MATCHROM); |
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for(uint8_t i=0; i<8; i++) {
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onewire_tx_byte(id[i]); |
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} |
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} |
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void onewire_skiprom(void) {
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onewire_reset(); |
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onewire_tx_byte(ONEWIRE_CMD_SKIPROM); |
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} |
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typedef struct {
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bool done; |
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uint8_t next_id; |
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state->bit_pattern[bit_index / 8] |= (1<<(bit_index % 8)); |
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} else if(bit_index > state->prev_deviation) {
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state->bit_pattern[bit_index / 8] &= ~(1<<(bit_index % 8)); |
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} else if(bit_pattern[bit_index / 8] & (1<<(bit_index % 8)) == 0) {
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deviation = bit_index; |
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} else if((state->bit_pattern[bit_index / 8] & (1<<(bit_index % 8))) == 0) {
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deviation = bit_index; |
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} |
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} |
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if(bit_pattern[bit_index / 8] & (1<<(bit_index % 8))) {
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if(state->bit_pattern[bit_index / 8] & (1<<(bit_index % 8))) {
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onewire_tx1(); |
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} else {
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onewire_tx0(); |
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} |
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} |
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if(deviation = -1) state->done = true; |
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if(deviation == -1) state->done = true;
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state->prev_deviation = deviation; |
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return true; |
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} |
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onewire_search_state_t state; |
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state.done = false; |
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state.next_id = 0; |
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state.deviation = -1; |
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memset(bit_pattern, 0, sizeof(onewire_id)); |
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state.prev_deviation = -1;
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memset(state.bit_pattern, 0, sizeof(onewire_id));
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while(*n > 0 && onewire_search_iter(&state)) {
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memcpy(id_list[state.next_id++], state.bit_pattern, sizeof(onewire_id)); |
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*n--;
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*n = *n - 1;
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} |
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*n = state.next_id; |
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} |
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static uint8_t onewire_crc8_byte(uint8_t seed, uint8_t data) {
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const uint8_t poly = 0x18; |
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for(uint8_t i=0; i<8; i++) {
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if((data ^ seed) & 1) {
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seed = ((seed ^ poly) >> 1) | 0x80; |
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} else {
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seed >>= 1; |
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} |
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data >>= 1; |
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} |
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return seed; |
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} |
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uint8_t onewire_crc8(uint8_t *data, uint8_t length) {
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uint8_t crc = 0; |
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for(; length > 0; length--) {
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crc = onewire_crc8_byte(crc, *data++); |
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} |
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return crc; |
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} |
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bool onewire_crc_rom(onewire_id id) {
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return onewire_crc8(id, 8) == 0; |
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} |
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void onewire_convert_t(void) {
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onewire_tx_byte(ONEWIRE_CMD_CONVERT_T); |
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} |
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void onewire_write_scratchpad(uint8_t th, uint8_t tl, uint8_t config) {
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onewire_tx_byte(ONEWIRE_CMD_WRITE_SCRATCHPAD); |
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onewire_tx_byte(th); |
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onewire_tx_byte(tl); |
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onewire_tx_byte(config); |
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} |
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bool onewire_read_scratchpad(ds18b20_scratchpad_t *scratchpad) {
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onewire_tx_byte(ONEWIRE_CMD_READ_SCRATCHPAD); |
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uint8_t *buf = (uint8_t*)scratchpad; |
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for(uint8_t i=0; i<sizeof(ds18b20_scratchpad_t); i++) {
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*buf++ = onewire_rx_byte(); |
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} |
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return onewire_crc8((uint8_t*)scratchpad, sizeof(ds18b20_scratchpad_t)) == 0; |
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} |
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