New to Arduino. Can't seems to get moisture sensor to work.

I've been stuck on this project for about two weeks now. I wanted to make just moisture sensor and water pump and nothing else.

I've tried to follow this:

As for moisture sensor, I tried to use this design:

I have used so many codes that I lost count. I mostly just find code for everything then remove everything that isn't moisture sensor then upload it.

One of the problem I have is... It seems like no matter what I do, the sensor never seems to work or have any input. I would successfully upload it and everything only to have no reply from sensor. I couldn't measure anything.

Where am I suppose to see the amount of moisture in the soil and how do I get it to show? I really need help with this.

Thanks in advance.

recheck the wiring around the resistor on the protoboard.
End of the resistor should go to +5V, the other to A0 and the nail.

Can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png or pdf?

Can you please post a copy of your sketch, using code tags?
Please use code tags.. See section 7,148850.0.html

Hope it helps..... Tom..... :slight_smile:

Damn... I need to learn to be more patient :drooling_face:

I took them all apart already to try something else... But I will reset them then try wire them just the way you describe it and take a picture of it.

Sorry I tend to have very little patience. So when something go wrong, I don't just sit and wait. I tend to just pull everything apart and start over or fiddle around.

Thanks for the suggestion. Will try that now and let you know what happen and take a picture as well!

Here's the code I'm using. Yes it show 0 but even after I pour generous amount of water in soil, nothing change. I even reset the Arduino and uploaded code again with no luck :frowning:

  # Example code for the moisture sensor
  # Editor     : Lauren
  # Date       : 13.01.2012
  # Version    : 1.0
  # Connect the sensor to the A0(Analog 0) pin on the Arduino board
  # the sensor value description
  # 0  ~300     dry soil
  # 300~700     humid soil
  # 700~950     in water

void setup(){

void loop(){
  Serial.print("Moisture Sensor Value:");

Here's my set up (Not sure if I draw it correctly... Still new to this):

try this.....
Do you have a DMM?

Tom..... :slight_smile:

May I ask what is DMM? Will try that and get back to you.

Ok... I tried to do what you showed me. But I'm not sure about how the breadboard is suppose to go... As the part where the 5v connect with resistor and nail and 0 analog really throw me off.

But here's pic. I didnt have any luck :frowning:

Digital Multi-Meter

It was my first thought also, lets see what the sensor is doing first...

Try putting everything next to everything else and then taking a photo from an angle where people can read (or at least figure out) which pins you're connecting to on the arduino.

A good example of this is the original image you posted from garduino.

If you have a DMM, try setting to 'beep' out the connections (or at least see very low resistance), to see if your breadboard connections are good (or if they are even internally pooped, as can be in the case of cheap ones) - at the least google how they work to be sure

Some makes of breadboard have a break in the rails as shown attached. If yours is one of those, then the wire A at far left is not connected to the one at far right B.


Cables can be dodgy, check all connectivity there if you're still wondering.

A multimeter is essential for ongoing projects of this kind :wink:

Looks like JimboZA is right, one of your pics shows break in the red and blue lines.
In your last picture, place the purple lead to 5V and the orange to the analog input and the nail.
The other nail to gnd of the UNO.

Tom...... :slight_smile:
Is your monitor set to 75600?
When you connect the nails together you should get 0 or near zero, with the nails in open air you should get a high reading up around 900 - 1000.
I can't see properly but are you connected to A0?

Ive been making a circuit with a moisture sensor module, only difference being that i am trying to light an LED when moisture is low, I'm getting sensible readings from he sensor, but my led wont light up once i hit the threshold that i have set.
I have looked for projects like mine all over the place, but cannot find any.

That would suggest you need to look at the LED wiring and set up in code.

Have you done that?

If you'd like us to help you might want to share the information you gleaned in doing so :slight_smile: