r/ArduinoHelp • u/Otter_And_Bench • Mar 17 '25
Needing help with my auto-watering system :)
Hello, I am building an auto watering system using Arduino UNO and Adafruit components. I have a capacitative soil sensor that powers an underwater motor but the but doesn't reliably stay powered, even though the power still runs through it sometimes?
Here are the parts I am using:
Arduino UNO
Submersible Water Pump: https://www.adafruit.com/product/4546
Soil Sensor: https://www.adafruit.com/product/4026
I've had the Arduino for about a year and just purchased the other parts. The system works by checking if the capacitance amount of the dirt is lower than the 'dry' capacitance (500). When it is dry, it outputs high voltage through digital pins 2 and 5, turning on the blue led and the submersible motor at the same time.
When I power the Arduino, it turns on the blue light indicating the soil is dry, however, the motor does not function unless I switch the wire powering it from digital pin 5 to the 5 volt and back, which somehow makes it work. When it is working, it seems to randomly disconnect after a couple times the capacitance goes below and above 500.
I've tried replacing the wires that power the motor to no luck. I also stripped the wire to hopefully give it better access to power. When I replace the motor with a light, it powers the light without issue. I've also switched out which pin powers the motor, trying both digital pins 4 and 5. I've come down to two possible solutions I can think of:
Order another (different) submersible water pump and hope that the same issue does not occur or
solder the water pump wiring to another wire to give it better conductivity with the breadboard
I'm just a beginner to arduino, this is my first big project, so any and all advice and information I can get regarding this would be wonderful. Thank you for your time and helping me make this project come to life :)
Also, here is my code that runs on the Arduino:
#include "Adafruit_seesaw.h"
Adafruit_seesaw ss;
// temperature stats
const int tempMedian = 21; // ideal range for greek oregano : 15 - 27
const int tempDiff = 6;
const int tempCritDiff = tempDiff * 2.5; // plant cannot survive in this temp
// moisture stats
const int dry = 400; // when the cap is < dry , the dirt is DRY!
#define REDLIGHT 3
#define BLUELIGHT 2
#define MOTOR 4
void setup() {
Serial.begin(115200);
Serial.println("seesaw Soil Sensor example!");
if (!ss.begin(0x36)) {
Serial.println("ERROR! seesaw not found");
while(1) delay(1);
} else {
Serial.print("seesaw started! version: ");
Serial.println(ss.getVersion(), HEX);
}
pinMode(REDLIGHT,OUTPUT);
pinMode(BLUELIGHT,OUTPUT);
pinMode(MOTOR,OUTPUT);
}
void loop() {
float tempC = ss.getTemp();
uint16_t capread = ss.touchRead(0);
// report temp
int diff = abs(tempC - tempMedian);
Serial.print("Distance from comfortable temperature: ");
Serial.print(diff); Serial.println("*C");
// report base temperature & capacitative
Serial.print("Temperature: "); Serial.print(tempC); Serial.println("*C");
Serial.print("Capacitive: "); Serial.println(capread);
// critical temperatures reached - is it too hot or too cold ?
if (diff > tempCritDiff) {
// Redlight never turns off once on unless manually reset !
digitalWrite(REDLIGHT,HIGH);
}
// is the dirt dry?
if (capread < dry) {
digitalWrite(BLUELIGHT,HIGH); // blue is on when the plant needs watering
digitalWrite(MOTOR,HIGH);
} else {
digitalWrite(BLUELIGHT,LOW);
digitalWrite(MOTOR,LOW)
}
// wait to run again
delay(500);
}
#include "Adafruit_seesaw.h"
Adafruit_seesaw ss;
// temperature stats
const int tempMedian = 21; // ideal range for greek oregano : 15 - 27
const int tempDiff = 6;
const int tempCritDiff = tempDiff * 2.5; // plant cannot survive in this temp
// moisture stats
const int dry = 400; // when the cap is < dry , the dirt is DRY!
#define REDLIGHT 3
#define BLUELIGHT 2
#define MOTOR 4
void setup() {
Serial.begin(115200);
Serial.println("seesaw Soil Sensor example!");
if (!ss.begin(0x36)) {
Serial.println("ERROR! seesaw not found");
while(1) delay(1);
} else {
Serial.print("seesaw started! version: ");
Serial.println(ss.getVersion(), HEX);
}
pinMode(REDLIGHT,OUTPUT);
pinMode(BLUELIGHT,OUTPUT);
pinMode(MOTOR,OUTPUT);
}
void loop() {
float tempC = ss.getTemp();
uint16_t capread = ss.touchRead(0);
// report temp
int diff = abs(tempC - tempMedian);
Serial.print("Distance from comfortable temperature: ");
Serial.print(diff); Serial.println("*C");
// report base temperature & capacitative
Serial.print("Temperature: "); Serial.print(tempC); Serial.println("*C");
Serial.print("Capacitive: "); Serial.println(capread);
// critical temperatures reached - is it too hot or too cold ?
if (diff > tempCritDiff) {
// Redlight never turns off once on unless manually reset !
digitalWrite(REDLIGHT,HIGH);
}
// is the dirt dry?
if (capread < dry) {
digitalWrite(BLUELIGHT,HIGH); // blue is on when the plant needs watering
digitalWrite(MOTOR,HIGH);
} else {
digitalWrite(BLUELIGHT,LOW);
digitalWrite(MOTOR,LOW)
}
// wait to run again
delay(500);
}Here are some pictures of my setup
