Introduction: [Waterproof DS18B20 Sensor Kit Tutorial_1] DIY: Auto AC for Your Pet Fish

About: a maker

The sweat came out in a fine dew on my forehead when I left a room with AC and get outdoor yesterday. It just came up to my mind that my pet fish may need their own auto AC since I would go for a trip some day. So I DIY an AC through Waterproof DS18B20 Digital Temperature Sensor from DFrobot. It suits every rectangular fishbowl and costs little power.

Step 1: Deal With All the Hardware Connection(NO SOLDERING REQUIRED)

Step 2: Install Arduino IDE

Open the next URL and pick the correct version for your machine.

Step 3: Upload the Code &Add Library Through This Button.


int DS18S20_Pin = 2; //DS18S20 Signal pin on digital 2

int E1 = 5;

int M1 = 4;

int E2 = 6;

int M2 = 7;

//Temperature chip i/o

OneWire ds(DS18S20_Pin); // on digital pin 2

void setup(void) {


pinMode(4, OUTPUT);

pinMode(7, OUTPUT);


void loop(void) {

int value =0;

float temperature= getTemp();



if(temperature > 25.00)



digitalWrite(M2, HIGH);

analogWrite(E1, 255); //PWM

analogWrite(E2, 255); //PWM





digitalWrite(M2, LOW);

analogWrite(E1, 0); //PWM

analogWrite(E2, 0); //PWM



//just here to slow down the output so it is easier to read


float getTemp(){

//returns the temperature from one DS18S20 in DEG Celsius

byte data[12];

byte addr[8];

if ( ! {

//no more sensors on chain, reset search


return -1000;


if ( OneWire::crc8( addr, 7) != addr[7]) {

Serial.println("CRC is not valid!");

return -1000;


if ( addr[0] != 0x10 && addr[0] != 0x28) {

Serial.print("Device is not recognized");

return -1000;



ds.write(0x44,1); // start conversion, with parasite power on at the end

byte present = ds.reset();;

ds.write(0xBE); // Read Scratchpad

for (int i = 0; i < 9; i++) { // we need 9 bytes

data[i] =;



byte MSB = data[1];

byte LSB = data[0];

float tempRead = ((MSB << 8) | LSB); //using two's compliment

float TemperatureSum = tempRead / 16;

return TemperatureSum;


Step 4: Decorate Your Project and Make It Suitable for the Size of the Fishbowl

Step 5: Check Everything Yourself!!!

Leave your pet fish a ‘coolest’ summer ever.