Build your own infrared camera

Everything You Need

Table 1 includes all of the components that you will need to construct an infrared camera. In addition to the Raspberry Pi, the most important items are the touch display and the NoIR camera module. You can connect the module to the suitable port on the Rasp Pi by following the instructions.

I chose to use the 2.8-inch touch display from pi3g [4] introduced in a previous article [5]. The basic installation without camera software works about the same as for a normal setup. A modified image provided by the touch display manufacturer contains all of the drivers necessary for installation [6].

A good way to install the display is to start by connecting a network cable, logging in, and then calling the normal configuration with the sudo raspi-config command. Here, you can activate support for the camera, set the language and keyboard layout, and arrange for the computer to boot in the command line.

Assigning a permanent IP address makes for convenient access to the camera via the (local) network. Testing the component parts for functionality is accomplished via the

raspistill -o test.jpg

command. Then, you should copy the test file onto the PC and review the first picture produced by the camera. As an alternative, you can install the Linux image viewer fbi to view the photograph directly on the touch display (Listing 1).

$ sudo apt-get update
$ sudo apt-get install fbi
$ sudo fbi -T 1 --noverbose -a test.jpg

The Insides

In addition to the core components of the camera, the operating system should include an SD card for storing images. You should consider having a card with a fair amount of storage capacity. Pi3g offers a half-sized SD card [7] that doesn't stick out, making it easier to fit the camera components into a case.

A small WiFi dongle, such as the Edimax EW-7811UN, can assume communication with the outside world, making it possible to download pictures. A dongle is not absolutely necessary, but it does make copying pictures onto the PC much easier.

Finally, you need a power supply. Infrared photography usually only works when there is a lot of light. Thus, you can use an off-the-shelf charger, like those used to charge mobile phones, for mobile charging capabilities. The charger will need to deliver the 1.2Ah required by the Rasp Pi.

The Anker Astro E5 shown in Figure 4 offers good capacity and can easily power the Raspberry Pi for several hours. However, it does have one disadvantage, namely, it has an on button but no off button. As a result, the user has to disconnect the cable leading to the Rasp Pi or risk having a computer that has been shut down because the battery was sucked dry. The solution to this shortcoming is to solder an off switch onto a USB cable.

Figure 4: A mobile battery can power the Raspberry Pi for hours when out of range of an electrical outlet.