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/**
* |----------------------------------------------------------------------
* | Copyright (C) Tilen Majerle, 2014
* |
* | This program is free software: you can redistribute it and/or modify
* | it under the terms of the GNU General Public License as published by
* | the Free Software Foundation, either version 3 of the License, or
* | any later version.
* |
* | This program is distributed in the hope that it will be useful,
* | but WITHOUT ANY WARRANTY; without even the implied warranty of
* | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* | GNU General Public License for more details.
* |
* | You should have received a copy of the GNU General Public License
* | along with this program. If not, see <http://www.gnu.org/licenses/>.
* |----------------------------------------------------------------------
*/
#include "tm_stm32f4_ds18b20.h"
uint8_t TM_DS18B20_Start(TM_OneWire_t* OneWire, uint8_t *ROM) {
/* Check if device is DS18B20 */
if (!TM_DS18B20_Is(ROM)) {
return 0;
}
/* Reset line */
TM_OneWire_Reset(OneWire);
/* Select ROM number */
TM_OneWire_SelectWithPointer(OneWire, ROM);
/* Start temperature conversion */
TM_OneWire_WriteByte(OneWire, DS18B20_CMD_CONVERTTEMP);
return 1;
}
void TM_DS18B20_StartAll(TM_OneWire_t* OneWire) {
/* Reset pulse */
TM_OneWire_Reset(OneWire);
/* Skip rom */
TM_OneWire_WriteByte(OneWire, ONEWIRE_CMD_SKIPROM);
/* Start conversion on all connected devices */
TM_OneWire_WriteByte(OneWire, DS18B20_CMD_CONVERTTEMP);
}
uint8_t TM_DS18B20_Read(TM_OneWire_t* OneWire, uint8_t *ROM, float *destination) {
uint16_t temperature;
uint8_t resolution;
int8_t digit, minus = 0;
float decimal;
uint8_t i = 0;
uint8_t data[9];
uint8_t crc;
/* Check if device is DS18B20 */
if (!TM_DS18B20_Is(ROM)) {
return 0;
}
/* Check if line is released, if it is, then conversion is complete */
if (!TM_OneWire_ReadBit(OneWire)) {
/* Conversion is not finished yet */
return 0;
}
/* Reset line */
TM_OneWire_Reset(OneWire);
/* Select ROM number */
TM_OneWire_SelectWithPointer(OneWire, ROM);
/* Read scratchpad command by onewire protocol */
TM_OneWire_WriteByte(OneWire, ONEWIRE_CMD_RSCRATCHPAD);
/* Get data */
for (i = 0; i < 9; i++) {
/* Read byte by byte */
data[i] = TM_OneWire_ReadByte(OneWire);
}
/* Calculate CRC */
crc = TM_OneWire_CRC8(data, 8);
/* Check if CRC is ok */
if (crc != data[8]) {
/* CRC invalid */
return 0;
}
/* First two bytes of scratchpad are temperature values */
temperature = data[0] | (data[1] << 8);
/* Reset line */
TM_OneWire_Reset(OneWire);
/* Check if temperature is negative */
if (temperature & 0x8000) {
/* Two's complement, temperature is negative */
temperature = ~temperature + 1;
minus = 1;
}
/* Get sensor resolution */
resolution = ((data[4] & 0x60) >> 5) + 9;
/* Store temperature integer digits and decimal digits */
digit = temperature >> 4;
digit |= ((temperature >> 8) & 0x7) << 4;
/* Store decimal digits */
switch (resolution) {
case 9: {
decimal = (temperature >> 3) & 0x01;
decimal *= (float)DS18B20_DECIMAL_STEPS_9BIT;
} break;
case 10: {
decimal = (temperature >> 2) & 0x03;
decimal *= (float)DS18B20_DECIMAL_STEPS_10BIT;
} break;
case 11: {
decimal = (temperature >> 1) & 0x07;
decimal *= (float)DS18B20_DECIMAL_STEPS_11BIT;
} break;
case 12: {
decimal = temperature & 0x0F;
decimal *= (float)DS18B20_DECIMAL_STEPS_12BIT;
} break;
default: {
decimal = 0xFF;
digit = 0;
}
}
/* Check for negative part */
decimal = digit + decimal;
if (minus) {
decimal = 0 - decimal;
}
/* Set to pointer */
*destination = decimal;
/* Return 1, temperature valid */
return 1;
}
uint8_t TM_DS18B20_GetResolution(TM_OneWire_t* OneWire, uint8_t *ROM) {
uint8_t conf;
if (!TM_DS18B20_Is(ROM)) {
return 0;
}
/* Reset line */
TM_OneWire_Reset(OneWire);
/* Select ROM number */
TM_OneWire_SelectWithPointer(OneWire, ROM);
/* Read scratchpad command by onewire protocol */
TM_OneWire_WriteByte(OneWire, ONEWIRE_CMD_RSCRATCHPAD);
/* Ignore first 4 bytes */
TM_OneWire_ReadByte(OneWire);
TM_OneWire_ReadByte(OneWire);
TM_OneWire_ReadByte(OneWire);
TM_OneWire_ReadByte(OneWire);
/* 5th byte of scratchpad is configuration register */
conf = TM_OneWire_ReadByte(OneWire);
/* Return 9 - 12 value according to number of bits */
return ((conf & 0x60) >> 5) + 9;
}
uint8_t TM_DS18B20_SetResolution(TM_OneWire_t* OneWire, uint8_t *ROM, TM_DS18B20_Resolution_t resolution) {
uint8_t th, tl, conf;
if (!TM_DS18B20_Is(ROM)) {
return 0;
}
/* Reset line */
TM_OneWire_Reset(OneWire);
/* Select ROM number */
TM_OneWire_SelectWithPointer(OneWire, ROM);
/* Read scratchpad command by onewire protocol */
TM_OneWire_WriteByte(OneWire, ONEWIRE_CMD_RSCRATCHPAD);
/* Ignore first 2 bytes */
TM_OneWire_ReadByte(OneWire);
TM_OneWire_ReadByte(OneWire);
th = TM_OneWire_ReadByte(OneWire);
tl = TM_OneWire_ReadByte(OneWire);
conf = TM_OneWire_ReadByte(OneWire);
if (resolution == TM_DS18B20_Resolution_9bits) {
conf &= ~(1 << DS18B20_RESOLUTION_R1);
conf &= ~(1 << DS18B20_RESOLUTION_R0);
} else if (resolution == TM_DS18B20_Resolution_10bits) {
conf &= ~(1 << DS18B20_RESOLUTION_R1);
conf |= 1 << DS18B20_RESOLUTION_R0;
} else if (resolution == TM_DS18B20_Resolution_11bits) {
conf |= 1 << DS18B20_RESOLUTION_R1;
conf &= ~(1 << DS18B20_RESOLUTION_R0);
} else if (resolution == TM_DS18B20_Resolution_12bits) {
conf |= 1 << DS18B20_RESOLUTION_R1;
conf |= 1 << DS18B20_RESOLUTION_R0;
}
/* Reset line */
TM_OneWire_Reset(OneWire);
/* Select ROM number */
TM_OneWire_SelectWithPointer(OneWire, ROM);
/* Write scratchpad command by onewire protocol, only th, tl and conf register can be written */
TM_OneWire_WriteByte(OneWire, ONEWIRE_CMD_WSCRATCHPAD);
/* Write bytes */
TM_OneWire_WriteByte(OneWire, th);
TM_OneWire_WriteByte(OneWire, tl);
TM_OneWire_WriteByte(OneWire, conf);
/* Reset line */
TM_OneWire_Reset(OneWire);
/* Select ROM number */
TM_OneWire_SelectWithPointer(OneWire, ROM);
/* Copy scratchpad to EEPROM of DS18B20 */
TM_OneWire_WriteByte(OneWire, ONEWIRE_CMD_CPYSCRATCHPAD);
return 1;
}
uint8_t TM_DS18B20_Is(uint8_t *ROM) {
/* Checks if first byte is equal to DS18B20's family code */
if (*ROM == DS18B20_FAMILY_CODE) {
return 1;
}
return 0;
}
uint8_t TM_DS18B20_SetAlarmLowTemperature(TM_OneWire_t* OneWire, uint8_t *ROM, int8_t temp) {
uint8_t tl, th, conf;
if (!TM_DS18B20_Is(ROM)) {
return 0;
}
if (temp > 125) {
temp = 125;
}
if (temp < -55) {
temp = -55;
}
/* Reset line */
TM_OneWire_Reset(OneWire);
/* Select ROM number */
TM_OneWire_SelectWithPointer(OneWire, ROM);
/* Read scratchpad command by onewire protocol */
TM_OneWire_WriteByte(OneWire, ONEWIRE_CMD_RSCRATCHPAD);
/* Ignore first 2 bytes */
TM_OneWire_ReadByte(OneWire);
TM_OneWire_ReadByte(OneWire);
th = TM_OneWire_ReadByte(OneWire);
tl = TM_OneWire_ReadByte(OneWire);
conf = TM_OneWire_ReadByte(OneWire);
tl = (uint8_t)temp;
/* Reset line */
TM_OneWire_Reset(OneWire);
/* Select ROM number */
TM_OneWire_SelectWithPointer(OneWire, ROM);
/* Write scratchpad command by onewire protocol, only th, tl and conf register can be written */
TM_OneWire_WriteByte(OneWire, ONEWIRE_CMD_WSCRATCHPAD);
/* Write bytes */
TM_OneWire_WriteByte(OneWire, th);
TM_OneWire_WriteByte(OneWire, tl);
TM_OneWire_WriteByte(OneWire, conf);
/* Reset line */
TM_OneWire_Reset(OneWire);
/* Select ROM number */
TM_OneWire_SelectWithPointer(OneWire, ROM);
/* Copy scratchpad to EEPROM of DS18B20 */
TM_OneWire_WriteByte(OneWire, ONEWIRE_CMD_CPYSCRATCHPAD);
return 1;
}
uint8_t TM_DS18B20_SetAlarmHighTemperature(TM_OneWire_t* OneWire, uint8_t *ROM, int8_t temp) {
uint8_t tl, th, conf;
if (!TM_DS18B20_Is(ROM)) {
return 0;
}
if (temp > 125) {
temp = 125;
}
if (temp < -55) {
temp = -55;
}
/* Reset line */
TM_OneWire_Reset(OneWire);
/* Select ROM number */
TM_OneWire_SelectWithPointer(OneWire, ROM);
/* Read scratchpad command by onewire protocol */
TM_OneWire_WriteByte(OneWire, ONEWIRE_CMD_RSCRATCHPAD);
/* Ignore first 2 bytes */
TM_OneWire_ReadByte(OneWire);
TM_OneWire_ReadByte(OneWire);
th = TM_OneWire_ReadByte(OneWire);
tl = TM_OneWire_ReadByte(OneWire);
conf = TM_OneWire_ReadByte(OneWire);
th = (uint8_t)temp;
/* Reset line */
TM_OneWire_Reset(OneWire);
/* Select ROM number */
TM_OneWire_SelectWithPointer(OneWire, ROM);
/* Write scratchpad command by onewire protocol, only th, tl and conf register can be written */
TM_OneWire_WriteByte(OneWire, ONEWIRE_CMD_WSCRATCHPAD);
/* Write bytes */
TM_OneWire_WriteByte(OneWire, th);
TM_OneWire_WriteByte(OneWire, tl);
TM_OneWire_WriteByte(OneWire, conf);
/* Reset line */
TM_OneWire_Reset(OneWire);
/* Select ROM number */
TM_OneWire_SelectWithPointer(OneWire, ROM);
/* Copy scratchpad to EEPROM of DS18B20 */
TM_OneWire_WriteByte(OneWire, ONEWIRE_CMD_CPYSCRATCHPAD);
return 1;
}
uint8_t TM_DS18B20_DisableAlarmTemperature(TM_OneWire_t* OneWire, uint8_t *ROM) {
uint8_t tl, th, conf;
if (!TM_DS18B20_Is(ROM)) {
return 0;
}
/* Reset line */
TM_OneWire_Reset(OneWire);
/* Select ROM number */
TM_OneWire_SelectWithPointer(OneWire, ROM);
/* Read scratchpad command by onewire protocol */
TM_OneWire_WriteByte(OneWire, ONEWIRE_CMD_RSCRATCHPAD);
/* Ignore first 2 bytes */
TM_OneWire_ReadByte(OneWire);
TM_OneWire_ReadByte(OneWire);
th = TM_OneWire_ReadByte(OneWire);
tl = TM_OneWire_ReadByte(OneWire);
conf = TM_OneWire_ReadByte(OneWire);
th = 125;
tl = (uint8_t)-55;
/* Reset line */
TM_OneWire_Reset(OneWire);
/* Select ROM number */
TM_OneWire_SelectWithPointer(OneWire, ROM);
/* Write scratchpad command by onewire protocol, only th, tl and conf register can be written */
TM_OneWire_WriteByte(OneWire, ONEWIRE_CMD_WSCRATCHPAD);
/* Write bytes */
TM_OneWire_WriteByte(OneWire, th);
TM_OneWire_WriteByte(OneWire, tl);
TM_OneWire_WriteByte(OneWire, conf);
/* Reset line */
TM_OneWire_Reset(OneWire);
/* Select ROM number */
TM_OneWire_SelectWithPointer(OneWire, ROM);
/* Copy scratchpad to EEPROM of DS18B20 */
TM_OneWire_WriteByte(OneWire, ONEWIRE_CMD_CPYSCRATCHPAD);
return 1;
}
uint8_t TM_DS18B20_AlarmSearch(TM_OneWire_t* OneWire) {
/* Start alarm search */
return TM_OneWire_Search(OneWire, DS18B20_CMD_ALARMSEARCH);
}
uint8_t TM_DS18B20_AllDone(TM_OneWire_t* OneWire) {
/* If read bit is low, then device is not finished yet with calculation temperature */
return TM_OneWire_ReadBit(OneWire);
}
|
