Measuring and Controlling the pH of Water by the Internet of Things

Abstract

This paper presents the development of the system for pH control by the Internet of Things (IoT) to reduce difficulties in and enhance the convenience of the control of the pH of water used in agriculture. The system is operated by using a pH sensor that transmits signals to Node MCU ESP8266 with a 2.4 GHz Wi-Fi module, which is used as a processor and a controller, as well as connecting with the cloud server of the NETPIE platform. pH control can be performed on site or by remote control using a smartphone, a tablet, or a computer. In the case that the pH value of water is higher or lower than a predetermined value, the processor activates the motor to release acid or alkaline substances in order to adjust the pH value of water to fall within a preferred range, and then such adjusted water is released for use. The test results of the above-mentioned system revealed that it was effective in two modes, namely the fish selection mode in which it took 16.38 minutes to increase the pH of acidic water (pH = 5.39) up to 6.58 and it took 14.29 minutes to decrease the pH of alkaline water (pH = 9.80) down to 8.46, and the vegetable selection mode in which it took 18.02 minutes to increase the pH of acidic water (pH = 4.78) up to 5.63 and it took 18.33 minutes to decrease the pH of alkaline water (pH = 8.32) down to 6.85.