TDS measurement – ​​micro:bit with LCD OMG Robotics

To measure TDS (Total Dissolved Solids) with a micro:bit, you’ll need a TDS sensor. This sensor can be connected to the micro:bit’s expansion board or directly to the micro:bit’s pins using appropriate wiring.

Here’s a general approach to measuring TDS with a micro:bit:

1. Connect the Sensor:

   • Connect the sensor’s power, ground, and analog signal pins to the corresponding pins on the micro:bit or expansion board.
   • Refer to the specific sensor’s documentation for exact wiring instructions.

2. Program the Micro:bit:

   • Use a programming language like MakeCode or Python to write code that reads the analog signal from the TDS sensor.
   • Convert the analog reading to a TDS value using a calibration curve or a lookup table.
   • Display the TDS value on the micro:bit’s LED screen or send it to a connected device.

Here’s a basic MakeCode code example:

let sensorPin = AnalogPin.P0
let tdsValue = 0

basic.forever(() => {
    tdsValue = pins.analogReadPin(sensorPin)
    // Convert the analog reading to TDS value (calibration required)
    basic.showNumber(tdsValue)
})

Important Considerations:

• Calibration: Calibrate the sensor using solutions of known TDS values to ensure accurate readings.
• Power Supply: Ensure that the sensor and micro:bit are powered correctly.
• Environmental Factors: Temperature and pressure can affect the sensor’s readings, so consider compensating for these factors.
• Sensor Sensitivity: Choose a sensor with appropriate sensitivity for your application.

Additional Tips:

• Use a Clear and Informative Display: Display the TDS value on an LCD screen or a mobile app for easy reading.
• Log Data: Store the sensor data for analysis and visualization.
• Integrate with Other Sensors: Combine the TDS sensor with other sensors like temperature and humidity sensors for more comprehensive environmental monitoring.

By following these steps and considering the factors mentioned above, you can effectively use a micro:bit to measure TDS and gain valuable insights into water quality.