Grove - TDS Sensor

The Grove - TDS Sensor detects the Total Dissolved Solids (TDS) levels in the water which can be used to indicate the water quality. The Grove - TDS Sensor can be applied in water quality applications such as TDS meter, well water, aquarium, hydroponics, etc.

It supports 3.3 / 5V input voltage and 0 ~ 2.3V Output Voltage making it easy to be compatible with all Arduino Boards. The sensor also provides a waterproof probe, making the testing process much easier to handle.


  • Analog Signal, easy to implement
  • Support 3.3 / 5V Input Voltage
  • Good Arduino Compatibility, where 0 ~ 2.3V Output Voltage can be easily implemented in 3.3 / 5V control system
  • Waterproof TDS Probe


Parameter Value
Input voltage 3.3V / 5V
Output Voltage 0 ~ 2.3V
Working Current 3 ~ 6 mA
TDS Measurement Range 0 ~ 1000ppm
Connection Interface Grove 4-Pin / XHB 2.54mm 2P
Interface Analog
Cable Length 60cm
Connection Interface XHB 2.54mm 2P

Hardware Overview

Platforms Supported

Arduino Raspberry Pi

Getting Started

Play With Arduino

Materials required

Seeeduino V4.2 Base Shield Grove - TDS Sensor
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In addition, you can consider our new Seeeduino Lotus M0+, which is equivalent to the combination of Seeeduino V4.2 and Baseshield.

Hardware Connection

  • Step 1. Plug Grove - TDS Sensor to A0 port of Grove - Base Shield.

  • Step 2. Plug Grove - Base Shield into Seeeduino.

  • Step 3. Connect Seeeduino to a PC via a USB cable.



If this is the first time you work with Arduino, we strongly recommend you to see Getting Started with Arduino before the start.

  • Step 1. Open the Arduino IDE and create a new file, then copy the following code into the new file.
#define SERIAL Serial
#define sensorPin A0

int sensorValue = 0;
float tdsValue = 0;
float Voltage = 0;

void setup() {
void loop() {
    sensorValue = analogRead(sensorPin);
    Voltage = sensorValue*5/1024.0; //Convert analog reading to Voltage
    tdsValue=(133.42/Voltage*Voltage*Voltage - 255.86*Voltage*Voltage + 857.39*Voltage)*0.5; //Convert voltage value to TDS value
    SERIAL.print("TDS Value = "); 
    SERIAL.println(" ppm");
  • Step 3. Upload the demo. If you do not know how to upload the code, please check How to upload code.

  • Step 4. Open the Serial Monitor of Arduino IDE by click Tool-> Serial Monitor. Or tap the Ctrl+Shift+M key at the same time. Set the baud rate to 9600.

  • Step 5. The result should be like this when the probe is in water:

Play With Raspberry Pi

Materials required

Raspberry Pi Grove Base Hat for RasPi Grove - TDS Sensor
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  • Step 2. Plug the Grove Base Hat into Raspberry Pi.

  • Step 3. Connect the Grove - TDS sensor to port A0 of the Base Hat.

  • Step 4. Connect the Raspberry Pi to PC through USB cable.


  • Step 1. Follow Setting Software to configure the development environment.

  • Step 2. Download the source file by cloning the grove python library.

cd ~
git clone https://github.com/Seeed-Studio/grove.py
  • Step 3. Execute below commands to create the python code.
cd grove.py/grove/
nano TDS.py
  • Step 4. Copy the following code into the file:
import math
import sys
import time
from grove.adc import ADC

class GroveTDS:

    def __init__(self, channel):
        self.channel = channel
        self.adc = ADC()

    def TDS(self):
        value = self.adc.read(self.channel)
        if value != 0:
            voltage = value*5/1024.0
            tdsValue = (133.42/voltage*voltage*voltage-255.86*voltage*voltage+857.39*voltage)*0.5
            return tdsValue
            return 0

Grove = GroveTDS

def main():
    if len(sys.argv) < 2:
        print('Usage: {} adc_channel'.format(sys.argv[0]))

    sensor = GroveTDS(int(sys.argv[1]))
    print('Detecting TDS...')

    while True:
        print('TDS Value: {0}'.format(sensor.TDS))

if __name__ == '__main__':
  • Step 5. Use Ctrl+O to save and Ctrl+X to quit.

  • Step 6. Run the following to execute:

python TDS.py 0


If everything goes well, you will be able to see the following result:

pi@raspberrypi:~/grove.py/grove$ python TDS.py 0
Detecting TDS...
TDS Value: 0
TDS Value: 0
TDS Value: 0
TDS Value: 0
TDS Value: 2.41591963768
TDS Value: 28.5884239197
TDS Value: 33.2677587509
TDS Value: 30.9311414242
TDS Value: 30.9311414242


Q1# Limitations of Grove - TDS Sensor/Meter For Water Quality (Total Dissolved Solids)?

A1: Limitations are as followed:

  • The Waterproof TDS probe cannot be used in water above 70°C.
  • The sensor cannot be used to measure flowing water.
  • The sensor cannot be used to measure water with high pollution concentration.
  • The Grove sensor itself is not waterproof.

Schematic Online Viewer


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