Temperature Sensing: RTD4 and T4

Introduction #

This tutorial explains how to measure temperature using NORVI X expansion modules. It covers two temperature-sensing solutions: the NORVI X-RTD4, which supports PT100 and PT1000 RTD sensors, and the NORVI X-T4, which supports 2-wire NTC thermistors.

Required Hardware #

Understanding the Sensors #

PT100 / PT1000 #

• RTD (Resistance Temperature Detector)
• Resistance changes with temperature
• PT100 = 100 Ω at 0°C
• PT1000 = 1000 Ω at 0°C
• Used with the X-RTD4

NTC Thermistor (10kΩ) #

• NTC = Negative Temperature Coefficient
• Resistance decreases as temperature increases
• 2-wire sensor connection
• Used with the X-T4

NORVI X-RTD4 – PT100 / PT1000 #

The NORVI X-RTD4 is a 4-channel RTD temperature input module. It reads 4 sensor inputs and is used in industrial, HVAC, and process monitoring applications.

For a detailed application, follow our ESP32 PT100 temperature monitoring tutorial to learn how NORVI X-RTD4 acquires temperature data from industrial equipment and displays the measurements on a NORVI X controller.

A. Sensor wiring #

The NORVI X-RTD4 supports PT100 and PT1000 RTD temperature sensors. PT100 has a nominal resistance of 100 Ω at 0°C, while PT1000 has 1000 Ω at 0°C. For a 2-wire connection, connect the two sensor wires to the corresponding RTD input terminals. The X-RTD4 provides four channels (RTD1–RTD4), allowing up to four PT100 or PT1000 sensors to be connected and used for temperature measurement.

B. Sensor configuration #

1. Connect the X-RTD4 to the NORVI X CPU.
2. Connect the PT100 or PT1000 sensor to the corresponding RTD input terminals.
3. Select the appropriate sensor type using the DIP switch.
   • Set the DIP switch to PT100 when using PT100 sensors.
   • Set the DIP switch to PT1000 when using PT1000 sensors.
   • PT100 and PT1000 sensors cannot be used together at the same time. All connected sensors must be the same type selected by the DIP switch.
4. Configure the input according to the selected sensor type.
5. Read the measured temperature.

NORVI X-T4 – 2-Wire NTC Thermistor #

The NORVI X-T4 is a 4-channel NTC thermistor temperature input module. It reads 4 sensor inputs and supports 2-wire NTC thermistors for cost-effective temperature sensing.

A. Sensor wiring #

For a 2-wire NTC sensor, connect the two sensor wires to the corresponding input terminals of Channel 1–4. The NTC sensor is non-polarized, so either wire can be connected to either terminal. Ensure that the sensor is connected to the correct channel and terminals.

Learn how to implement ESP32 temperature monitoring using NTC thermistors with the NORVI X-T4 expansion module, including resistance-to-temperature conversion, live display readings, and temperature alarm configuration.

B. Sensor configuration #

1. Connect the X-T4 expansion module to the appropriate expansion port on the NORVI X CPU.
2. Connect the NTC thermistor. Connect the 2-wire NTC thermistor to the selected input channel. Since the NTC is non-polarized, wires can be swapped within the same channel.
3. Configure the thermistor parameters such as the NTC resistance value and temperature parameters, according to the sensor and specifications.
4. Read the temperature value from the corresponding X-T4 input channel after completing the configuration.

Software / Programming #

Set Up → Configure → Upload → Monitor → Verify

1. Arduino IDE Setup
   Configure the board and communication port:

• Tools → Board → ESP32 Arduino → ESP32S3 Dev Module
• Tools → Port → Select the corresponding COM/serial port

Under the Tools menu, configure the following settings:

2. Required Libraries
   Install the libraries required for the NORVI X CPU and temperature module.

• Wire
• SPI
• TFT_eSPI
• CST816S
• Adafruit_ADS1X15
• Free_Fonts

3. Upload the Example Code
   Connect the NORVI X CPU via USB, select the correct COM port, and upload the program.

Testing the Temperature Sensor #

Test 1 – Room temperature #

• Connect sensor
• Read temperature
• Record value

Test 2 – Change the temperature #

• Warm the sensor carefully
• Observe the temperature increase
• Compare the readings

Test 3 – Multiple sensors #

• Connect sensors to several channels
• Display each channel separately.

Troubleshooting #

Comparison: X-RTD4 vs X-T4 #

A final comparison would help users choose the appropriate module.