/*
xsns_ds18x20.ino - DS18x20 temperature sensor support for Sonoff-Tasmota
Copyright (C) 2017 Heiko Krupp and Theo Arends
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
(at your option) 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 .
*/
#ifdef USE_DS18x20
/*********************************************************************************************\
* DS18B20 - Temperature
\*********************************************************************************************/
#define DS18S20_CHIPID 0x10
#define DS18B20_CHIPID 0x28
#define MAX31850_CHIPID 0x3B
#define W1_SKIP_ROM 0xCC
#define W1_CONVERT_TEMP 0x44
#define W1_READ_SCRATCHPAD 0xBE
#define DS18X20_MAX_SENSORS 8
#include
OneWire *ds = NULL;
uint8_t ds18x20_addr[DS18X20_MAX_SENSORS][8];
uint8_t ds18x20_idx[DS18X20_MAX_SENSORS];
uint8_t ds18x20_snsrs = 0;
char dsbstype[9];
void ds18x20_init()
{
ds = new OneWire(pin[GPIO_DSB]);
}
void ds18x20_search()
{
uint8_t num_sensors=0;
uint8_t sensor = 0;
uint8_t i;
ds->reset_search();
for (num_sensors = 0; num_sensors < DS18X20_MAX_SENSORS; num_sensors) {
if (!ds->search(ds18x20_addr[num_sensors])) {
ds->reset_search();
break;
}
// If CRC Ok and Type DS18S20, DS18B20 or MAX31850
if ((OneWire::crc8(ds18x20_addr[num_sensors], 7) == ds18x20_addr[num_sensors][7]) &&
((ds18x20_addr[num_sensors][0]==DS18S20_CHIPID) || (ds18x20_addr[num_sensors][0]==DS18B20_CHIPID) || (ds18x20_addr[num_sensors][0]==MAX31850_CHIPID))) {
num_sensors++;
}
}
for (int i = 0; i < num_sensors; i++) {
ds18x20_idx[i] = i;
}
for (int i = 0; i < num_sensors; i++) {
for (int j = i + 1; j < num_sensors; j++) {
if (uint32_t(ds18x20_addr[ds18x20_idx[i]]) > uint32_t(ds18x20_addr[ds18x20_idx[j]])) {
std::swap(ds18x20_idx[i], ds18x20_idx[j]);
}
}
}
ds18x20_snsrs = num_sensors;
}
uint8_t ds18x20_sensors()
{
return ds18x20_snsrs;
}
String ds18x20_address(uint8_t sensor)
{
char addrStr[20];
uint8_t i;
for (i = 0; i < 8; i++) {
sprintf(addrStr+2*i, "%02X", ds18x20_addr[ds18x20_idx[sensor]][i]);
}
return String(addrStr);
}
void ds18x20_convert()
{
ds->reset();
ds->write(W1_SKIP_ROM); // Address all Sensors on Bus
ds->write(W1_CONVERT_TEMP); // start conversion, no parasite power on at the end
// delay(750); // 750ms should be enough for 12bit conv
}
boolean ds18x20_read(uint8_t sensor, float &t)
{
byte data[12];
int8_t sign = 1;
uint8_t i = 0;
float temp9 = 0.0;
uint8_t present = 0;
t = NAN;
ds->reset();
ds->select(ds18x20_addr[ds18x20_idx[sensor]]);
ds->write(W1_READ_SCRATCHPAD); // Read Scratchpad
for (i = 0; i < 9; i++) {
data[i] = ds->read();
}
if (OneWire::crc8(data, 8) == data[8]) {
switch(ds18x20_addr[ds18x20_idx[sensor]][0]) {
case DS18S20_CHIPID: // DS18S20
/*
// App_note AN162.pdf page 9
int temp_lsb, temp_msb;
temp_msb = data[1]; // Sign byte + lsbit
temp_lsb = data[0]; // Temp data plus lsb
if (temp_msb <= 0x80) temp_lsb = (temp_lsb/2); // Shift to get whole degree
temp_msb = temp_msb & 0x80; // Mask all but the sign bit
if (temp_msb >= 0x80) { // Negative temperature
temp_lsb = (~temp_lsb)+1; // Twos complement
temp_lsb = (temp_lsb/2); // Shift to get whole degree
temp_lsb = ((-1)*temp_lsb); // Add sign bit
}
t = (int)temp_lsb; // Temperature in whole degree
*/
if (data[1] > 0x80) {
data[0] = (~data[0]) +1;
sign = -1; // App-Note fix possible sign error
}
if (data[0] & 1) {
temp9 = ((data[0] >> 1) + 0.5) * sign;
} else {
temp9 = (data[0] >> 1) * sign;
}
t = convertTemp((temp9 - 0.25) + ((16.0 - data[6]) / 16.0));
break;
case DS18B20_CHIPID: // DS18B20
case MAX31850_CHIPID: // MAX31850
uint16_t temp12 = (data[1] << 8) + data[0];
if (temp12 > 2047) {
temp12 = (~temp12) +1;
sign = -1;
}
t = convertTemp(sign * temp12 * 0.0625);
break;
}
}
return (!isnan(t));
}
/*********************************************************************************************\
* Presentation
\*********************************************************************************************/
void ds18x20_type(uint8_t sensor)
{
strcpy_P(dsbstype, PSTR("DS18x20"));
switch(ds18x20_addr[ds18x20_idx[sensor]][0]) {
case DS18S20_CHIPID:
strcpy_P(dsbstype, PSTR("DS18S20"));
break;
case DS18B20_CHIPID:
strcpy_P(dsbstype, PSTR("DS18B20"));
break;
case MAX31850_CHIPID:
strcpy_P(dsbstype, PSTR("MAX31850"));
break;
}
}
void ds18x20_mqttPresent(uint8_t* djson)
{
char stemp1[10];
char stemp2[10];
float t;
byte dsxflg = 0;
for (byte i = 0; i < ds18x20_sensors(); i++) {
if (ds18x20_read(i, t)) { // Check if read failed
ds18x20_type(i);
dtostrfd(t, sysCfg.flag.temperature_resolution, stemp2);
if (!dsxflg) {
snprintf_P(mqtt_data, sizeof(mqtt_data), PSTR("%s, \"DS18x20\":{"), mqtt_data);
*djson = 1;
stemp1[0] = '\0';
}
dsxflg++;
snprintf_P(mqtt_data, sizeof(mqtt_data), PSTR("%s%s\"DS%d\":{\"" D_TYPE "\":\"%s\", \"" D_ADDRESS "\":\"%s\", \"" D_TEMPERATURE "\":%s}"),
mqtt_data, stemp1, i +1, dsbstype, ds18x20_address(i).c_str(), stemp2);
strcpy(stemp1, ", ");
#ifdef USE_DOMOTICZ
if (1 == dsxflg) {
domoticz_sensor(0, stemp2);
}
#endif // USE_DOMOTICZ
}
}
if (dsxflg) {
snprintf_P(mqtt_data, sizeof(mqtt_data), PSTR("%s}"), mqtt_data);
}
}
#ifdef USE_WEBSERVER
String ds18x20_webPresent()
{
String page = "";
char stemp[10];
char stemp2[16];
char sensor[80];
float t;
for (byte i = 0; i < ds18x20_sensors(); i++) {
if (ds18x20_read(i, t)) { // Check if read failed
ds18x20_type(i);
dtostrfi(t, sysCfg.flag.temperature_resolution, stemp);
snprintf_P(stemp2, sizeof(stemp2), PSTR("%s-%d"), dsbstype, i +1);
snprintf_P(sensor, sizeof(sensor), HTTP_SNS_TEMP, stemp2, stemp, tempUnit());
page += sensor;
}
}
ds18x20_search(); // Check for changes in sensors number
ds18x20_convert(); // Start Conversion, takes up to one second
return page;
}
#endif // USE_WEBSERVER
#endif // USE_DS18x20