WATER LEVEL And TEMPERATURE MONITOR With TFT Graphics Using Arduino

Water and temperature monitoring systems are crucial across various industries, including the chemical, pharmaceutical, and textile sectors. They help maintain precise liquid levels and stable temperatures—factors essential to ensuring product quality.

- By ASHUTOSH M. BHATT

In chemical processing, for instance, both parameters must remain within defined limits throughout the operation.

This system uses contact or non-contact water level sensors along with a probe-type temperature sensor. A digital display provides continuous, real-time monitoring of liquid level and temperature.

Traditional systems often rely on basic LED indicators or 7-segment displays, which do not show actual water volume (in litres) or precise temperature (in degrees Celsius). Some modern systems do feature LCDs that display both parameters with numerical accuracy.

This system demonstrates water level and temperature monitoring on a 10.92cm (4.3-inch) TFT LCD using graphics and colour-changing animation of water filling a tank, along with a rising temperature bar graph. Fig. 1 shows the prototype on the left and a snapshot of the TFT display on the right. The components required to build the system are listed in Table 1.

Circuit and working

Fig. 2 shows the hardware connections, and Fig. 3 shows the circuit diagram. The system is built around the HC-SR04 ultrasonic sensor (S2), DS18B20 waterproof temperature sensor (S1), Arduino Nano (MOD1), a 10.92cm (4.3-inch) SPI TFT display (MOD2), and a few other components. The TFT display (480 x 320 resolution) shows the actual water level (in litres) and temperature. Resistors are used for signal conditioning, pull-up, and voltage-level shifting.

The TRIG and ECHO pins of the ultrasonic sensor connect to D4 and D3, respectively, to measure distance by calculating the time between pulse transmission and echo reception. The TFT display connects through SPI lines: SCK to D13, SDI to D12, SDO to D11, DC to D10, RST to D9, and CS to D8. Resistors R1 through R12 ensure the safe operation of the TFT module.