Adding a switch to nodeMCU and Thingspeak

Introduction

This is a simple step from my Wi-Fi Aquarium monitor. The code came from the IDE example: 02: Digital : Button.

Wiring

Connect your liquid level switch according to the schematic

Init

// Part of INI
// LEVEL sensor part
float level = 0;
const int levelPin = 14; // the number of the pushbutton pin ( D5 )
int buttonState = 0;

Copy part 1 to the IDE

Setup

// Part of SETUP
// LEVEL sensor input
 pinMode(levelPin, INPUT);

Copy part 2 to the SETUP

Main loop

// Part of MAIN LOOP
// Read LEVEL sensor
   buttonState = digitalRead(levelPin);
   if (buttonState == HIGH) {
     // turn level high
   level = 250;
   }
   else {
     // turn level low
   level = 10;

This step actually turns an open switch into a high and a closed switch into a low value. It's just basic stuff so it should work with all kinds of hardware.

IoT

The last step of this instruction is to send the data to Thingspeak. I am using a program that was written by Jeroen Beemster. His site is down but you can find the code in my fifth hackster project. The program did create a problem with the ADA library but i found a solution for it on the internet. ( Go down to credits )

• Add a field 4 to your Thingspeak account

• Copy the last block to your program

Good luck with implementing these steps

Input 14 ( levelPin ) is also called GPIO14
Mount the switch with the wires on top

Before you order this kind of liquid level switch, make sure it's Normally Open (NO) and will close is the lower position.