Sometimes only one sensor gives out spikes (not necessarily the red one), other times all the 4 sensors’ values jump high or low with some un-natural values, not necessarily all in the same direction (i.e. some spikes are ‘upwards’, some are ‘downwards’).
Please find below the code we are using to get the measured values from the sensors.
Thank you,
Darius
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TMP117 sensor1, sensor2, sensor3, sensor4;
bool isValid1 = false, isValid2 = false, isValid3 = false, isValid4 = false;
bool hasTemp1 = false, hasTemp2 = false, hasTemp3 = false, hasTemp4 = false;
long msTMP117Start = 0;
uint16_t msTMP117TIMEOUT = 2500;
int val_null = -99;
// sensor address
uint8_t ADDR1 = 0x48, ADDR2 = 0x49, ADDR3 = 0x4A, ADDR4 = 0x4B;
/* --------- INIT the sensors ------------------- */
void initTMP117(){
// 1. Check if the sensor will correctly self-identify with the proper Device ID/Address
beginSensors(1); beginSensors(2); beginSensors(3); beginSensors(4);
// 2. oneShotmeasurement, average = 1, cycle bit = 1 (125ms)
if (isValid1) {setOneshotMode(sensor1); sensor1.setConversionAverageMode(1); sensor1.setConversionCycleBit(1);}
if (isValid2) {setOneshotMode(sensor2); sensor2.setConversionAverageMode(1); sensor2.setConversionCycleBit(1);}
if (isValid3) {setOneshotMode(sensor3); sensor3.setConversionAverageMode(1); sensor3.setConversionCycleBit(1);}
if (isValid4) {setOneshotMode(sensor4); sensor4.setConversionAverageMode(1); sensor4.setConversionCycleBit(1);}
}
bool beginSensors(uint8_t idSensor) {
if (idSensor == 1) {
isValid1 = sensor1.begin(ADDR1, Wire);
if (isValid1) {DEBUG_STREAM.println(“I found 0x48 sensor”);}
else {DEBUG_STREAM.println(“Failed to setup sensor 0x48.”);}
return isValid1;
} else if (idSensor == 2) {
isValid2 = sensor2.begin(ADDR2, Wire);
if (isValid2) {DEBUG_STREAM.println(“I found 0x49 sensor”);}
else {DEBUG_STREAM.println(“Failed to setup sensor 0x49.”);}
return isValid2;
} else if (idSensor == 3) {
isValid3 = sensor3.begin(ADDR3, Wire);
if (isValid3) {DEBUG_STREAM.println(“I found 0x4A sensor”);}
else {DEBUG_STREAM.println(“Failed to setup sensor 0x4A.”);}
return isValid3;
} else {
isValid4 = sensor4.begin(ADDR4, Wire);
if (isValid4) {DEBUG_STREAM.println(“I found 0x4B sensor”);}
else {DEBUG_STREAM.println(“Failed to setup sensor 0x4B.”);}
return isValid4;
}
}
bool setOneshotMode(TMP117 sensor) {
sensor.setOneShotMode();
if (sensor.getConversionMode() == 3 ) { return true;}
return false;
}
/* --------- STATES MACHINE FOR TMP117 VALUES READINGS ------------------- */
int ReadTemperatures(int sens_status) {
// *** (STATE == 0) GENERAL INIT *************************************
if (sens_status == 0 ){
delayMicroseconds (5000);
hasTemp1 = false; hasTemp2 = false; hasTemp3 = false; hasTemp4 = false;
tmp117.T1 = val_null; tmp117.T2 = val_null; tmp117.T3 = val_null; tmp117.T4 = val_null;
sens_status = 1;
// *** (STATE == 1) INIT SENSOR 1 *******************************
} else if (sens_status == 1) {
sens_status = init_temp_sensor (sensor1, 1, sens_status);
// *** (STATE == 2) READ SENSOR 1 *******************************
} else if (sens_status == 2) {
sens_status = read_temp_sensor(sensor1, 1, sens_status, hasTemp1);
// *** (STATE == 3) INIT SENSOR 2 *******************************
} else if (sens_status == 3) {
sens_status = init_temp_sensor (sensor2, 2, sens_status);
// *** (STATE == 4) READ SENSOR 2 *******************************
} else if (sens_status == 4) {
sens_status = read_temp_sensor(sensor2, 2, sens_status, hasTemp2);
// *** (STATE == 5) INIT SENSOR 3 *******************************
} else if (sens_status == 5) {
sens_status = init_temp_sensor (sensor3, 3, sens_status);
// *** (STATE == 6) READ SENSOR 3 *******************************
} else if (sens_status == 6) {
sens_status = read_temp_sensor(sensor3, 3, sens_status, hasTemp3);
// *** (STATE == 7) INIT SENSOR 4 *******************************
} else if (sens_status == 7) {
sens_status = init_temp_sensor (sensor4, 4, sens_status);
// *** (STATE == 8) READ SENSOR 4 *******************************
} else if (sens_status == 8) {
sens_status = read_temp_sensor(sensor4, 4, sens_status, hasTemp4);
// *** (STATE == 9) DISPLAY DATA ********************
} else if (sens_status == 9) {
displayTMP117("TMP117 values ", tmp117);
sens_status = 0;
delay(60000);
}
return sens_status;
}
uint8_t init_temp_sensor (TMP117& _sensor, uint8_t _idSensor, int _status) {
bool result = false;
msTMP117Start = millis(); // used for timeout
result = beginSensors(_idSensor); // init temperature sensor
if(!result) {return (_status + 2);} // sensor not valid (not found) → no reading
result = setOneshotMode(_sensor); // set ONE SHOT MODE
if (!result) {
DEBUG_STREAM.print(F("Error setting one shot mode, for sensor "));
DEBUG_STREAM.println(_idSensor);
}
delayMicroseconds (150000); // wait for temperature to be ready
return (_status + 1); // next state
}
uint8_t read_temp_sensor(TMP117& _sensor, uint8_t _idSensor, int _status, bool& _hasTemp) {
if (!_hasTemp) {_hasTemp = readTemp(_sensor, _idSensor);}
if (_hasTemp) {
return (_status + 1); // it’s OK → next state
} else if ((millis() - msTMP117Start) > msTMP117TIMEOUT) {
if (!_hasTemp) {
DEBUG_STREAM.print(F("For TMP117 sensor "));
DEBUG_STREAM.print(_idSensor); DEBUG_STREAM.println(F(“, timeout occured!”));
}
return (_status + 1); // timeout → next state
}
return _status;
}
bool readTemp(TMP117& sensor, byte id) {
// read and save value from sensor
float tempC = val_null;
if (sensor.dataReady() == true) {
tempC = sensor.readTempC();
if (tempC != val_null) {
if (id == 1) {tmp117.T1 = tempC;}
else if (id == 2) {tmp117.T2 = tempC;}
else if (id == 3) {tmp117.T3 = tempC;}
else if (id == 4) {tmp117.T4 = tempC;}
return true;
}
}
return false;
}
void printTMP117settings(){
DEBUG_STREAM.println(F(" "));
printTMP117settings(sensor1, isValid1); // display setttings for sensor 1
printTMP117settings(sensor2, isValid2); // display setttings for sensor 2
printTMP117settings(sensor3, isValid3); // display setttings for sensor 3
printTMP117settings(sensor4, isValid4); // display setttings for sensor 4
}
void printTMP117settings(TMP117 sensor, bool isValid) {
if (isValid) {
DEBUG_STREAM.print(F("Sensor "));
DEBUG_STREAM.print(sensor.getAddress(), HEX);
DEBUG_STREAM.print(F(", mode "));
DEBUG_STREAM.print(sensor.getConversionMode());
DEBUG_STREAM.print(F(", average "));
DEBUG_STREAM.print(sensor.getConversionAverageMode());
DEBUG_STREAM.print(F(", cycle bit "));
DEBUG_STREAM.print(sensor.getConversionCycleBit());
DEBUG_STREAM.print(F(", offset "));
DEBUG_STREAM.println(sensor.getTemperatureOffset());
} else {
DEBUG_STREAM.print(F("Sensor "));
DEBUG_STREAM.print(sensor.getAddress(), HEX);
DEBUG_STREAM.println(F(“, mode /, average /, cycle bit /, offset /”));
}
}
void displayTMP117(const char header[25], TMP117Data tmpSOIL) {
byte decimal = 7;
DEBUG_STREAM.print(F(“\r\n”)); DEBUG_STREAM.println(F(header));
DEBUG_STREAM.print(F("TEMP 1 = "));
DEBUG_STREAM.print(tmpSOIL.T1, decimal);
DEBUG_STREAM.print(F(", TEMP 2 = "));
DEBUG_STREAM.print(tmpSOIL.T2, decimal);
DEBUG_STREAM.print(F(", TEMP 3 = "));
DEBUG_STREAM.print(tmpSOIL.T3, decimal);
DEBUG_STREAM.print(F(", TEMP 4 = "));
DEBUG_STREAM.println(tmpSOIL.T4, decimal);
}
. Spikes did not appear anymore.