Central Nexus

Central Nexus Thermal Camera Project

Have you ever had the desire to see what can not be seen? I never had the ability to see in thermal infrared, and it is rather cool to be able to see in the thermal infrared part of the electromagnetic spectrum. Unfortunately, most thermal (FLIR) cameras are very expensive. In 2011 cameras frequently cost several thousand dollars. This project was created to develop a cheaper solution at a fraction of the cost back in 2011. In 2016, finding a fast one that attaches to your smartphone for about $250 became much easier, which makes this project less financially competitive. This overview is provided for educational and entertainment purposes.

The primary reason for the cost difference was the thermal infrared sensor. Instead of having a 2 dimensional array of sensors, a single sensor is moved in a raster scan pattern. Moving this single sensor takes time as seen in the video below. It's not fast. So while you have fewer costly sensors, it takes longer to take a picture. This means the camera can not take images of moving objects, and the objects have to be very still during the scanning.

The cheap-thermocam.tk website and YouTube provided a good starting point for this work. The initial version I posted on this web site improved on the reliability, accuracy and usability. I also removed source code dependencies on proprietary libraries and GPL source code.

A picture of the camera.

Combined picture of thermal and visual images of a water heater. Notice how the drain spout and thermostat are very warm. The insulation around the top of the water heater and the walls are cooler.

My 📷 picture gallery has other examples taken with my camera.

Below is a video of my latest prototype in action.

Parts

The following are the parts used in creating this camera.

• Arduino Project Enclosure
• 2x Servo - Small
• Pan/Tilt Bracket
• Arduino Uno or an Arduino variant
• Logic Level Converter needed when using a 5 volt version of the Arduino, which is the most common version.
• Break Away Headers - Straight
• Break Away Male Headers - Right Angle
• Microsoft LifeCam VX-700. Any cheap external camera that is recognized by your computer will do. This one had 640x480 pixel resolution, which is what I wrote the software to handle.
• Protoshield PCB for Arduino. Almost any Arduino prototype shield will do.
• MLX90614ESF-DCI. This model has the best accuracy and narrowest field of view.
• About a foot of ribbon cable. Almost any wire will do. At least 5 wires are needed to connect the sensor to the Arduino and laser.
• .100 KK Housings & Terminals 6 Cir. (2.54mm) for the ribbon cable.
• PCB board for holding the laser and sensor.
• A switch to turn the laser on or off.
• A laser for aiming the sensor and aligning the pictures.
• Small nuts and bolts (#2-56 x 1/4") to attach the servos.

The following additional parts and tools are used in creating this camera.

• Soldering iron
• Solder
• Wire cutters
• A standard drill or a Dremel drill for creating holes in the case

Construction Instructions

I wrote some simple instructions for building this camera over at http://www.instructables.com/id/Thermal-Camera/. Below is also the wiring diagram that some people find useful.

This is the wiring diagram to connect all the pieces together. Click on the picture for a larger view.

Download

The following are the downloads for the project. It is licensed under an MIT style license.

Software Features

Here are the main feature highlights of the Thermal Camera software.

• Allows saving and reading thermal image data.
• Tag thermal images with temperature point reading.
• Provides statistical image information.
• Ability to change the thermal image color scheme.
• Translated into the following languages:
  • Dutch
  • English
  • Finnish
  • French
  • German
  • Spanish

Contact

If you're in a frantic rush to build this project yourself, it may be quicker if you read this page again to find your answers. You can contact me if you have any questions or you want to share your experience building it.