unleashed-firmware/lib/onewire/one_wire_master.cpp
gornekich b405a22cd1
[FL-1167] Rework GPIO and EXTI with LL lib (#424)
* api-hal-gpio: rework gpio on ll
* one_wire_slave: rework gpio initialization
* interrupts: add attribute weak to hal exti interrupts handlers
* api-hal-gpio: add exti interrupt handlers
* input: rework with api-hal-gpio interrupts
* one_wire_slave: rework with api-hal-gpio interrupts
* api-hal-gpio: fix incorrect exti line config
* api-hal-gpio: add doxygen documentation
* api-hal-gpio: add enable / disable interrupts
* api-hal-gpio: add get_rfid_level
* core: remove api-gpio
* applications: rework gpio with api-hal-gpio
* lib: rework gpio with api-hal-gpio
* rfal: disable exti interrupt when rfal is inactive
* rfal: add interrupt gpio reinitialization
* api-hal-gpio: hide setting speed and pull mode LL implementation
* stm32wbxx_it: remove unused EXTI handlers
* api-hal-gpio: guard set, enable, disable and remove interrupt
* Drop F4 target
* Accessor: update gpio api usage

Co-authored-by: Aleksandr Kutuzov <alleteam@gmail.com>
2021-04-29 11:51:48 +03:00

247 lines
6.7 KiB
C++

#include "one_wire_master.h"
#include "one_wire_timings.h"
OneWireMaster::OneWireMaster(const GpioPin* one_wire_gpio) {
gpio = one_wire_gpio;
reset_search();
}
OneWireMaster::~OneWireMaster() {
stop();
}
void OneWireMaster::start(void) {
hal_gpio_init(gpio, GpioModeOutputOpenDrain, GpioPullNo, GpioSpeedLow);
}
void OneWireMaster::stop(void) {
hal_gpio_init(gpio, GpioModeAnalog, GpioPullNo, GpioSpeedLow);
}
void OneWireMaster::reset_search() {
// reset the search state
last_discrepancy = 0;
last_device_flag = false;
last_family_discrepancy = 0;
for(int i = 7;; i--) {
saved_rom[i] = 0;
if(i == 0) break;
}
}
void OneWireMaster::target_search(uint8_t family_code) {
// set the search state to find SearchFamily type devices
saved_rom[0] = family_code;
for(uint8_t i = 1; i < 8; i++) saved_rom[i] = 0;
last_discrepancy = 64;
last_family_discrepancy = 0;
last_device_flag = false;
}
uint8_t OneWireMaster::search(uint8_t* newAddr, bool search_mode) {
uint8_t id_bit_number;
uint8_t last_zero, rom_byte_number, search_result;
uint8_t id_bit, cmp_id_bit;
unsigned char rom_byte_mask, search_direction;
// initialize for search
id_bit_number = 1;
last_zero = 0;
rom_byte_number = 0;
rom_byte_mask = 1;
search_result = 0;
// if the last call was not the last one
if(!last_device_flag) {
// 1-Wire reset
if(!reset()) {
// reset the search
last_discrepancy = 0;
last_device_flag = false;
last_family_discrepancy = 0;
return false;
}
// issue the search command
if(search_mode == true) {
write(0xF0); // NORMAL SEARCH
} else {
write(0xEC); // CONDITIONAL SEARCH
}
// loop to do the search
do {
// read a bit and its complement
id_bit = read_bit();
cmp_id_bit = read_bit();
// check for no devices on 1-wire
if((id_bit == 1) && (cmp_id_bit == 1))
break;
else {
// all devices coupled have 0 or 1
if(id_bit != cmp_id_bit)
search_direction = id_bit; // bit write value for search
else {
// if this discrepancy if before the Last Discrepancy
// on a previous next then pick the same as last time
if(id_bit_number < last_discrepancy)
search_direction = ((saved_rom[rom_byte_number] & rom_byte_mask) > 0);
else
// if equal to last pick 1, if not then pick 0
search_direction = (id_bit_number == last_discrepancy);
// if 0 was picked then record its position in LastZero
if(search_direction == 0) {
last_zero = id_bit_number;
// check for Last discrepancy in family
if(last_zero < 9) last_family_discrepancy = last_zero;
}
}
// set or clear the bit in the ROM byte rom_byte_number
// with mask rom_byte_mask
if(search_direction == 1)
saved_rom[rom_byte_number] |= rom_byte_mask;
else
saved_rom[rom_byte_number] &= ~rom_byte_mask;
// serial number search direction write bit
write_bit(search_direction);
// increment the byte counter id_bit_number
// and shift the mask rom_byte_mask
id_bit_number++;
rom_byte_mask <<= 1;
// if the mask is 0 then go to new SerialNum byte rom_byte_number and reset mask
if(rom_byte_mask == 0) {
rom_byte_number++;
rom_byte_mask = 1;
}
}
} while(rom_byte_number < 8); // loop until through all ROM bytes 0-7
// if the search was successful then
if(!(id_bit_number < 65)) {
// search successful so set last_Discrepancy, last_device_flag, search_result
last_discrepancy = last_zero;
// check for last device
if(last_discrepancy == 0) last_device_flag = true;
search_result = true;
}
}
// if no device found then reset counters so next 'search' will be like a first
if(!search_result || !saved_rom[0]) {
last_discrepancy = 0;
last_device_flag = false;
last_family_discrepancy = 0;
search_result = false;
} else {
for(int i = 0; i < 8; i++) newAddr[i] = saved_rom[i];
}
return search_result;
}
bool OneWireMaster::reset(void) {
uint8_t r;
uint8_t retries = 125;
// wait until the gpio is high
hal_gpio_write(gpio, true);
do {
if(--retries == 0) return 0;
delay_us(2);
} while(!hal_gpio_read(gpio));
// pre delay
delay_us(OneWireTiming::RESET_DELAY_PRE);
// drive low
hal_gpio_write(gpio, false);
delay_us(OneWireTiming::RESET_DRIVE);
// release
hal_gpio_write(gpio, true);
delay_us(OneWireTiming::RESET_RELEASE);
// read and post delay
r = !hal_gpio_read(gpio);
delay_us(OneWireTiming::RESET_DELAY_POST);
return r;
}
bool OneWireMaster::read_bit(void) {
bool result;
// drive low
hal_gpio_write(gpio, false);
delay_us(OneWireTiming::READ_DRIVE);
// release
hal_gpio_write(gpio, true);
delay_us(OneWireTiming::READ_RELEASE);
// read and post delay
result = hal_gpio_read(gpio);
delay_us(OneWireTiming::READ_DELAY_POST);
return result;
}
void OneWireMaster::write_bit(bool value) {
if(value) {
// drive low
hal_gpio_write(gpio, false);
delay_us(OneWireTiming::WRITE_1_DRIVE);
// release
hal_gpio_write(gpio, true);
delay_us(OneWireTiming::WRITE_1_RELEASE);
} else {
// drive low
hal_gpio_write(gpio, false);
delay_us(OneWireTiming::WRITE_0_DRIVE);
// release
hal_gpio_write(gpio, true);
delay_us(OneWireTiming::WRITE_0_RELEASE);
}
}
uint8_t OneWireMaster::read(void) {
uint8_t result = 0;
for(uint8_t bitMask = 0x01; bitMask; bitMask <<= 1) {
if(read_bit()) {
result |= bitMask;
}
}
return result;
}
void OneWireMaster::read_bytes(uint8_t* buffer, uint16_t count) {
for(uint16_t i = 0; i < count; i++) {
buffer[i] = read();
}
}
void OneWireMaster::write(uint8_t value) {
uint8_t bitMask;
for(bitMask = 0x01; bitMask; bitMask <<= 1) {
write_bit((bitMask & value) ? 1 : 0);
}
}
void OneWireMaster::skip(void) {
write(0xCC);
}