esp-open-rtos/extras/ds18b20/ds18b20.c
Alex Stewart d0ed5f03a2 A couple of fixups prior to merging into main project
Changed the ds_sensor_t struct to just return a float instead of major/minor
Renamed ds18b20.h functions to have consistent `ds18b20_*` naming.
Removed some unnecessary LICENSE files.  Clarified onewire origin/license.
2016-02-22 21:18:50 -08:00

103 lines
3.1 KiB
C

#include "onewire/onewire.h"
#include "ds18b20.h"
#define DS1820_WRITE_SCRATCHPAD 0x4E
#define DS1820_READ_SCRATCHPAD 0xBE
#define DS1820_COPY_SCRATCHPAD 0x48
#define DS1820_READ_EEPROM 0xB8
#define DS1820_READ_PWRSUPPLY 0xB4
#define DS1820_SEARCHROM 0xF0
#define DS1820_SKIP_ROM 0xCC
#define DS1820_READROM 0x33
#define DS1820_MATCHROM 0x55
#define DS1820_ALARMSEARCH 0xEC
#define DS1820_CONVERT_T 0x44
uint8_t ds18b20_read_all(uint8_t pin, ds_sensor_t *result) {
uint8_t addr[8];
uint8_t sensor_id = 0;
onewire_reset_search(pin);
while(onewire_search(pin, addr)){
uint8_t crc = onewire_crc8(addr, 7);
if (crc != addr[7]){
printf("CRC check failed: %02X %02X\n", addr[7], crc);
return 0;
}
onewire_reset(pin);
onewire_select(pin, addr);
onewire_write(pin, DS1820_CONVERT_T, ONEWIRE_DEFAULT_POWER);
sdk_os_delay_us(750);
onewire_reset(pin);
onewire_select(pin, addr);
onewire_write(pin, DS1820_READ_SCRATCHPAD, ONEWIRE_DEFAULT_POWER);
uint8_t get[10];
for (int k=0;k<9;k++){
get[k]=onewire_read(pin);
}
//printf("\n ScratchPAD DATA = %X %X %X %X %X %X %X %X %X\n",get[8],get[7],get[6],get[5],get[4],get[3],get[2],get[1],get[0]);
crc = onewire_crc8(get, 8);
if (crc != get[8]){
printf("CRC check failed: %02X %02X\n", get[8], crc);
return 0;
}
uint8_t temp_msb = get[1]; // Sign byte + lsbit
uint8_t temp_lsb = get[0]; // Temp data plus lsb
uint16_t temp = temp_msb << 8 | temp_lsb;
float temperature;
temperature = (temp * 625.0)/10000;
//printf("Got a DS18B20 Reading: %d.%02d\n", (int)temperature, (int)(temperature - (int)temperature) * 100);
result[sensor_id].id = sensor_id;
result[sensor_id].value = temperature;
sensor_id++;
}
return sensor_id;
}
float ds18b20_read_single(uint8_t pin) {
onewire_reset(pin);
onewire_write(pin, DS1820_SKIP_ROM, ONEWIRE_DEFAULT_POWER);
onewire_write(pin, DS1820_CONVERT_T, ONEWIRE_DEFAULT_POWER);
sdk_os_delay_us(750);
onewire_reset(pin);
onewire_write(pin, DS1820_SKIP_ROM, ONEWIRE_DEFAULT_POWER);
onewire_write(pin, DS1820_READ_SCRATCHPAD, ONEWIRE_DEFAULT_POWER);
uint8_t get[10];
for (int k=0;k<9;k++){
get[k]=onewire_read(pin);
}
//printf("\n ScratchPAD DATA = %X %X %X %X %X %X %X %X %X\n",get[8],get[7],get[6],get[5],get[4],get[3],get[2],get[1],get[0]);
uint8_t crc = onewire_crc8(get, 8);
if (crc != get[8]){
printf("CRC check failed: %02X %02X", get[8], crc);
return 0;
}
uint8_t temp_msb = get[1]; // Sign byte + lsbit
uint8_t temp_lsb = get[0]; // Temp data plus lsb
uint16_t temp = temp_msb << 8 | temp_lsb;
float temperature;
temperature = (temp * 625.0)/10000;
return temperature;
//printf("Got a DS18B20 Reading: %d.%02d\n", (int)temperature, (int)(temperature - (int)temperature) * 100);
}