Testing the STHS34PF80

Aug 6, 2024

I finally had some time to play with the new STHS34PF80 from ST. I’ve been excited to test it out since its release last year. It is an infrared motion and presence detection sensor that measures the difference between the ambient temperature and the object of interest using an ASIC. It is incredibly sensitive and can detect a human up to 4 meters away without an optical lens.

I’m particularly excited about this sensor because it checks so many of the boxes for using it in a low-cost and low-power device in the real world. As you can see in the chart below, it has a well balanced advantage over other common types of motion and presence sensors.

source - STMicroelectronics

For my first test, I monitored the door threshold of my office. I’m using the STHS34PF80 breakout board from Sparkfun. I also designed a simple stand to keep the board at a 90-degree angle. You can download the STL file here or the Fusion360 project here. If you’d like to see the Arduino code I was running, you can find it here, and the library it relies on here

You can set the threshold value for the ambient temperature difference with the object temperature to trigger the motion event. After a bit of trial and error, I found 300 to work well.

Next, I’d like to see if I can accurately detect the direction of motion using two STHS34PF80s. Stay tuned!