pH Monitor for Hydroponics

Overview

The analog pH probe board outputs a voltage the board converts to pH. Alerts tell you when the solution needs adjusting, which hydroponic plants are sensitive to.

Build Steps

1. 1

   Calibrate first

   Take readings in pH 4 and pH 7 buffer solutions and store the two-point slope before trusting values.

2. 2

   Read and convert

   Average the analog input, apply the calibration line and print pH on the OLED.

3. 3

   Set the window

   Warn with the buzzer when pH drifts outside 5.5–6.5 for most crops.

4. 4

   Handle the probe

   Rinse with distilled water, store in storage solution and never let the probe dry out.