Humidity and Temperature Arduino Project

Back in the day, we would study weather by making wind vanes out of wood and barometers to measure humidity and temperature. Now, we have Arduinos, pocket-sized micro controllers and computers, electronic sensors to do this. The good part is it’s so easy to do even for a child, and all you need to learn is just a search away. Another benefit is it’s affordability. You can buy the components on-line from Amazon, or Lazada.

I can now measure humidity and temperature electronically. And, to know if it will rain, humidity is one factor on predicting it.

Why bother making this if we have smartphone apps to do just the same? Well, those data came from sources only to a specific area and not specific to your place. Some parts of your city is raining and some parts are just cloudy, and they got those data only where they are situated in. Thus, this project.

These are the required components:

  • Arduino Uno.
  • 3 pins DHT11 Humidity and temperature sensor.
  • Breadboard.
  • Wires.
  • Laptop or Raspberry Pi

Here is the schematics: 


  1. You place the sensor on the breadboard.
  2. Attach black wire (whichever color you use), to the negative pin of the sensor. A minus (-) is indicated on the sensor and on to GND of the Arduino.
  3. Attach a white wire to the Output (the middle pin), and the end to Digital (2).
  4. Attach a red wire to the positive (+) pin of the sensor and the end to 5V.
  5. Download the source code: Source Code Zip File. Note: You need to install the Arduino IDE from
  6. Connect your Arduino to your laptop USB and upload the Arduino source code (it ends with the .ino file extension). For more info regarding setting up your Arduino, go to
  7. Once uploaded, go to the Folder and open a Powershell. You can do this easily by pressing the shift key while right-clicking it and choose Open Powershell.
  8. Inside the folder with the Python script (.py), run this on the shell (without the quotes): “python .\humidity_and_temp_sensor_dht11_3_”

If everything is connected properly, it will show the temperature and humidity in the Powershell console.


If it says, “error 101” then check your wiring. Your wires might be defective or not properly inserted on your breadboard. Replace your wires and move the sensor to another location on your breadboard.

Check the serial port where your Arduino is connected. In Arduino IDE, go to the menu and choose Tools->Port and see where it is connected. Go to Tools->Board Info to check if your Arduino is connected and working properly.

Check the Baud Rate if it is 9600.

Check if SimpleDHT Library is installed. Go to menu, Sketch->Include Library->Manage Libraries. Search for DHT (Simple DHT), and install it.

Some DHT11 3-pin sensors has different pin placements (There is even a four pin sensor). You can check it by looking at the label above the pins and it’s usually the plus and minus signs.


There you have it. A quick and easy way to learn more about your environment by using a temperature and humidity sensor and an Arduino.

If this is your first project, then “Congratulations!”

You can learn more about Arduinos from their official website and clicking the “Learn” link.

Or, you can visit Arduino Playground, there are some interesting ideas they have there:

Please share:


Health Smartphone

I’ve been evangelizing people about how practical the Apple watch is because of its health related features (even if I don’t own one). I’ve seen people using it and praising it for its health benefits by keeping you fit, and monitor your body for vital signs such as: calories, blood pressure, heart rate, sugar levels, and more. But, these features is confined to watches such as the Apple watch.

What if, you build a smartphone with these features by putting in sensors? Why not? That will differentiate this phone from others and it will also be super useful and brings a lot of value to a common, ubiquitous smartphone that we bring everyday and everywhere.

I’m not against buying ‘another’ device dedicated to this, but it is kind of a an inconvenience bringing two devices and always charging it both.

So, I guess this is kind of a suggestion that make smartphones even do more and help others to be healthy and enjoy life.

Vertical-Axis, Stacked Wind Turbine

This is a vertical-axis wind turbine that rotates in different wind direction, thus ensuring electricity generation efficiently. You can stack this into three per pole to provide more energy and saving space. Materials for this is cheaper using plastics, which is lighter for stability and easier deployment.

Here is a render:

Vertical Axis Stacked Wind Turbine

As you can see, the upper half of the sketch is just tilted vertically to view the scale of the turbine. The bottom half of the render shows the side view and the top view.

This is basically the same principle as the weather apparatus used to measure wind speed.


Fernando L. Cuevas Jr.


Dual-Screen Smartphone

I’ve always wanted a dedicated keyboard. A great solution is to have a second screen that is always-on for notifications, weather report if it will rain, messages, news ticker, a game controller, a finger print scanner, emojis and so on.

A second screen dedicated to these will save battery and you don’t have to unlock your phone while cooking or anything else.

Dual-screen phone


Fernando L. Cuevas Jr.

A Simple Electric Motor

This took me days to figure out what’s wrong. Although I got it from the Internet on how to make this, and there are step-by-step instructions, I just couldn’t figure it out. Luckily, after searching, I found a video that explains for this to work, you need the coil to have only one side exposed in a vertical manner. You just have to sand paper one side of the coil at both ends, touching the electric current from the battery.

Here is a picture:

A Simple Electric Motor

Here is a video demo:

For this to work:

  • You have to have a strong magnet.
  • An Alkaline 9 volt Battery.


How I wish that they use glass bottles again instead of plastic pet bottles. Glass bottles can be reused by dipping them in antiseptic solution and it is clean again, while pet bottles are just thrown and piled up in landfills that cause pollution on seas, riverbeds, poison the soil, kill wildlife and damage the ecosystem. If you’re going to recycle plastic, you’ll need expensive equipment and costs are high. While glass bottles are more cost effective and have longevity. 

Reuse is better than recycle.