Tasmota/tasmota/tasmota_xsns_sensor/xsns_26_lm75ad.ino
2026-01-03 18:29:30 +01:00

155 lines
4.7 KiB
C++

/*
xsns_26_lm75ad.ino - Support for I2C LM75AD Temperature Sensor
Copyright (C) 2021 Andre Thomas 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 <http://www.gnu.org/licenses/>.
*/
#ifdef USE_I2C
#ifdef USE_LM75AD
/*********************************************************************************************\
* LM75AD - Temperature
*
* Docs at https://www.nxp.com/docs/en/data-sheet/LM75A.pdf
*
* I2C Address: 0x48 - 0x4F
\*********************************************************************************************/
#define XSNS_26 26
#define XI2C_20 20 // See I2CDEVICES.md
#ifndef LM75AD_MAX_SENSORS
#define LM75AD_MAX_SENSORS 8
#endif
#define LM75AD_ADDRESS 0x48 // Start address
#define LM75AD_COUNT 8 // Number of sequential addresses
#define LM75_TEMP_REGISTER 0x00
#define LM75_CONF_REGISTER 0x01
#define LM75_THYST_REGISTER 0x02
#define LM75_TOS_REGISTER 0x03
struct {
uint8_t address[LM75AD_MAX_SENSORS];
uint8_t bus[LM75AD_MAX_SENSORS];
uint8_t count;
} Lm75;
void LM75ADDetect(void) {
if ((LM75AD_MAX_SENSORS < 1) || (LM75AD_MAX_SENSORS > 16)) { return; } // Safeguard user changed LM75AD_MAX_SENSORS out of bounds
for (uint32_t bus = 0; bus < 2; bus++) {
for (uint32_t address = LM75AD_ADDRESS; address < LM75AD_ADDRESS + LM75AD_COUNT; address++) {
if (!I2cSetDevice(address, bus)) { continue; } // Do not make the next step without a confirmed device on the bus
uint16_t buffer;
if (I2cValidRead16(&buffer, address, LM75_THYST_REGISTER, bus)) {
if (buffer == 0x4B00) {
I2cSetActiveFound(address, "LM75AD", bus);
Lm75.address[Lm75.count] = address;
Lm75.bus[Lm75.count] = bus;
Lm75.count++;
if (LM75AD_MAX_SENSORS == Lm75.count) { return; }
}
}
}
}
}
float LM75ADGetTemp(uint32_t sensor) {
uint16_t t;
if (I2cValidRead16(&t, Lm75.address[sensor], LM75_TEMP_REGISTER, Lm75.bus[sensor])) {
int16_t sign = 1;
if (t & 0x8000) { // We are getting a negative temperature value
t = (~t) +0x20;
sign = -1;
}
t = t >> 5; // Shift value into place (5 LSB not used)
return ConvertTemp(sign * t * 0.125f);
}
return NAN; // Will be changed to "null" by ext_vsprintf_P()
}
void LM75ADShow(bool json) {
for (uint32_t sensor = 0; sensor < Lm75.count; sensor++) {
float t = LM75ADGetTemp(sensor);
// if (!isnan(t)) {
char name[16];
// LM75AD
strlcpy(name, "LM75AD", sizeof(name));
if (Lm75.count > 1) {
// LM75AD-49
snprintf_P(name, sizeof(name), PSTR("%s%c%02X"), name, IndexSeparator(), Lm75.address[sensor]);
#ifdef USE_I2C_BUS2
if (TasmotaGlobal.i2c_enabled[1]) { // Second bus enabled
uint8_t bus = Lm75.bus[0];
for (uint32_t i = 1; i < Lm75.count; i++) {
if (bus != Lm75.bus[i]) { // Different busses
// LM75AD-49-1
snprintf_P(name, sizeof(name), PSTR("%s%c%d"), name, IndexSeparator(), Lm75.bus[sensor] +1);
break;
}
}
}
#endif // USE_I2C_BUS2
}
if (json) {
ResponseAppend_P(JSON_SNS_F_TEMP, name, Settings->flag2.temperature_resolution, &t);
#ifdef USE_DOMOTICZ
if ((0 == TasmotaGlobal.tele_period) && (0 == sensor)) {
DomoticzFloatSensor(DZ_TEMP, t);
}
#endif // USE_DOMOTICZ
#ifdef USE_WEBSERVER
} else {
WSContentSend_Temp(name, t);
#endif // USE_WEBSERVER
}
// }
}
}
/*********************************************************************************************\
* Interface
\*********************************************************************************************/
bool Xsns26(uint32_t function)
{
if (!I2cEnabled(XI2C_20)) { return false; }
bool result = false;
if (FUNC_INIT == function) {
LM75ADDetect();
}
else if (Lm75.count) {
switch (function) {
case FUNC_JSON_APPEND:
LM75ADShow(1);
break;
#ifdef USE_WEBSERVER
case FUNC_WEB_SENSOR:
LM75ADShow(0);
break;
#endif // USE_WEBSERVER
}
}
return result;
}
#endif // USE_LM75AD
#endif // USE_I2C