While digital cameras are common and inexpensive, thermal cameras—which function by mapping a grid of observed temperatures—are still rather specialized pieces of equipment. But the price of these sensors has become rather reasonable, to the point where you can procure the low-resolution Panasonic AMG8833 Grid-EYE® SMD format sensor for around $20.
Panasonic Thermal Sensor: AMG8833 Specs
This thermal sensor/low-res camera features 64 MEMS thermopile elements arranged in an 8x8 grid on a single chip. The device’s onboard electronics perform the calculations needed to map specific temperature data, which is output in a convenient I2C format. While an 8x8 resolution might not be able to capture the details of one’s face, applications for such a device could include detecting a person traversing a room, simple gesture control for devices at closer ranges, and much more.
Stats-wise, the device features a 60° viewing angle, which works out to be 7.5° per pixel. Temperature accuracy is ±2.5°C (±4.5°F), and is capable of operation from 0 to 80°C (32 to 176°F). It can detect a human within a range of 7m (~33ft) or closer, and appears to function reliably to sense a hand’s temperature within a few inches.
If you’d like to try out this sensor, there are a number of ready-made breakout boards available, including this Grove Board from Seeed and the SEN-14607 development board from SparkFun, used in this article.
Initial Setup: AMG8833 & Arduino Uno
The great news with this SEN-14607 board is that it’s extremely easy to set up. Instead of the proprietary Qwiic connection ports, I soldered headers to the GND, 3.3V, SDA, SCL, and INT pins, which are broken out on the board. SDA and SCL were connected to A4 and A5 on an Arduino Uno with jumpers, along with GND and 3.3V. Notably, you’ll need to specifically use 3.3V here, as this module is not 5V tolerant.
With this done, search for and install the SparkFun GridEYE AMG88 library on the Arduino IDE library manager, which can also be found on GitHub. Load up “Example1-SerialVisualizer,” and open up the serial monitor at 115200 baud. You can then pass your hand over the sensor to have it track your movements as a series of characters, based on adjustable HOT and COLD setpoints.
There are also examples that show the hottest pixel, device temperature, and one using interrupts. Another example uses processing to create an on-screen thermal camera, though I wasn’t able to get this working properly (using Processing 3 on a Mac).
Arduino Thermal Camera Sensor: All-in-one Solution?
If this device can be used to pass temperature info to a computer over serial, what about instead using it with an Arduino-controlled display for a portable low-res thermal camera? I’m not the first person to consider this usage, as Adafruit’s AMG88xx library–available via search on the Arduino IDE, or on GitHub–works perfectly with this 1.44” Color TFT LCD Display.
While this little display can supposedly work with 3.3V to match the needs of the AMG8833 sensor, I found it to be more stable when connected to a 5V source. For my setup, 5V was therefore used to supply the display, and 3.3V for the thermal sensor was taken off of the display’s “3v3” pin for wiring simplicity.
The display’s SCK, SO, SI, TCS, RST, and D/C pins hook directly into Arduino pins 13, 12 11, 10, 9, and 8 respectively, lining up quite nicely on the Uno. Sensor pin SCL goes to the top SCL pin on the Uno, while the SDA goes to the top SDA pin. From here, load the “thermal_cam” example from the Adafruit library, and the little screen will display a grid of colors that change depending on what’s presented in front of it. Notably, the “thermal_cam_interpolate” routine didn’t work on my setup, as it’s meant for a different screen.
Conclusion
After working with this device on the minimal SparkFun SEN-14607 breakout board via the available Arduino examples, it’s extremely easy to set up and use. There are a huge number of applications for such a device, and I can only imagine that integrating it into an actual product would be similarly straightforward.
While it won’t take the place of a much more expensive device with higher resolutions, it fills an interesting role where a single thermal sensor isn’t sufficient, but a full-fledged camera is overkill. Whether you need to design this into a product that will ship out to thousands or use it in a one-off device for a niche application, it’s a great option to have ready for when the need arises.
