41219cc78e
* fix Werror flag * strdup implementation fix * fix irda and lfrdid printf * remove unused position * doubtful type fix * type fix in EXTI interrupt * fix warnings in CubeWB, need to fork ST repo * onewire fixes * fork STM32WB Cube repo
116 lines
2.3 KiB
C++
116 lines
2.3 KiB
C++
#include "one_wire_master.h"
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#include "one_wire_timings.h"
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OneWireMaster::OneWireMaster(const GpioPin* one_wire_gpio) {
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gpio = one_wire_gpio;
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}
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OneWireMaster::~OneWireMaster() {
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stop();
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}
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void OneWireMaster::start(void) {
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gpio_init(gpio, GpioModeOutputOpenDrain);
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}
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void OneWireMaster::stop(void) {
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gpio_init(gpio, GpioModeAnalog);
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}
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bool OneWireMaster::reset(void) {
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uint8_t r;
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uint8_t retries = 125;
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// wait until the gpio is high
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gpio_write(gpio, true);
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do {
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if(--retries == 0) return 0;
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delay_us(2);
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} while(!gpio_read(gpio));
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// pre delay
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delay_us(OneWireTiming::RESET_DELAY_PRE);
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// drive low
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gpio_write(gpio, false);
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delay_us(OneWireTiming::RESET_DRIVE);
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// release
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gpio_write(gpio, true);
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delay_us(OneWireTiming::RESET_RELEASE);
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// read and post delay
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r = !gpio_read(gpio);
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delay_us(OneWireTiming::RESET_DELAY_POST);
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return r;
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}
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bool OneWireMaster::read_bit(void) {
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bool result;
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// drive low
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gpio_write(gpio, false);
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delay_us(OneWireTiming::READ_DRIVE);
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// release
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gpio_write(gpio, true);
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delay_us(OneWireTiming::READ_RELEASE);
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// read and post delay
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result = gpio_read(gpio);
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delay_us(OneWireTiming::READ_DELAY_POST);
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return result;
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}
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void OneWireMaster::write_bit(bool value) {
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if(value) {
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// drive low
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gpio_write(gpio, false);
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delay_us(OneWireTiming::WRITE_1_DRIVE);
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// release
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gpio_write(gpio, true);
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delay_us(OneWireTiming::WRITE_1_RELEASE);
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} else {
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// drive low
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gpio_write(gpio, false);
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delay_us(OneWireTiming::WRITE_0_DRIVE);
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// release
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gpio_write(gpio, true);
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delay_us(OneWireTiming::WRITE_0_RELEASE);
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}
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}
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uint8_t OneWireMaster::read(void) {
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uint8_t result = 0;
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for(uint8_t bitMask = 0x01; bitMask; bitMask <<= 1) {
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if(read_bit()) {
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result |= bitMask;
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}
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}
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return result;
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}
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void OneWireMaster::read_bytes(uint8_t* buffer, uint16_t count) {
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for(uint16_t i = 0; i < count; i++) {
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buffer[i] = read();
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}
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}
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void OneWireMaster::write(uint8_t value) {
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uint8_t bitMask;
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for(bitMask = 0x01; bitMask; bitMask <<= 1) {
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write_bit((bitMask & value) ? 1 : 0);
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}
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}
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void OneWireMaster::skip(void) {
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write(0xCC);
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}
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