~ I tried running the STHS34PF80 made by STMicroelectronics ~
This is a technical column by the development team at NEXTY Electronics.
We will provide information on hardware and software development using products handled by Nexty Electronics.
In this column, we will introduce the STHS34PF80 (TMOS IR sensor*1) manufactured by STMicroelectronics, which can be used in the market where demand for INFRARED LIGHT PHOTOSENSORS is increasing due to the trend toward smart homes, and write an article about how it actually works.
*1 TMOS: Abbreviation for Thermal MOS.
What is STHS34PF80?
The STHS34PF80 from STMicroelectronics is INFRARED LIGHT PHOTOSENSORS (IR sensor) that can detect the movement of objects and the presence of people by measuring the infrared radiation of objects within its field of view.
Its higher sensitivity and ability to sense stationary objects compared to known technologies such as traditional pyroelectric INFRARED LIGHT PHOTOSENSORS (PIR) offers many advantages to system designers.
This not only enables new applications but also reduces costs in existing systems, for example by eliminating the need for infrared concentrators such as Fresnel lenses.
TMOS IR Sensor Applications
- Home automation (presence detection/motion detection)
- Smart lighting (presence detection/motion detection/energy saving)
- Smart IoT home appliances (presence detection/motion detection/energy saving)
- Security alarm (presence detection/motion detection/energy saving)
Key benefits of the TMOS IR sensor
- Detect the presence of stationary or moving objects
- No Fresnel lens required for detecting objects at distances less than 4 meters
- Low power consumption thanks to built-in SMART algorithms
- Small package
- Digital Interface
Equipment used: Nexty Electronics original circuit board
At NEXTY Electronics, our in-house development department develops original circuit boards.
For this experiment to operate the STMicroelectronics STHS34PF80 (TMOS IR sensor), we also used the original board below.
MCU board
The MCU board is equipped with an STMicroelectronics MCU (STM32H753), and is primarily equipped with S DYNAMIC RAMS (256Mb), NOR-FLASH (512Mb), and an Audio codec.
In addition, an M.2 CONNECTORS is installed on the back of the board, allowing for expansion with a Wi-Fi/BT module and an LTM-M module.
Details of the board are explained here (STMicroelectronics MCU Reference Board | Technical Column).
MCU board
Expansion Board
The expansion board can be used in combination with sensor leaves (accelerometers, TEMPERATURE SENSORS, ATMOSPHERE SENSORS, CO2 sensors, etc.) that comply with the Leafony bus, a compact platform for IoT (*1 Leafony).It is also designed to be able to mount a gesture sensor from Analog Devices and a 60GHz radar from Nisshinbo Micro Devices.
*1 "Leafony" is a registered trademark of LEAFONY SYSTEMS, Inc. The T MOS SENSORS (STHS34PF80) introduced here is also mounted on the board.
*2 The red frame in the photo below is the STHS32PF80.
Expansion Board
T MOS SENSORS enlarged view
Configuration diagram
To control the T MOS SENSORS (STHS34PF80) from the MCU board, communication is performed using the I2C interface.
This time, we will read the register values of the T MOS SENSORS and display a graph of the raw data, human detection, and motion detection in a GUI.
STHS34PF80 (TMOS IR Sensor) in action
GUI screen
Let's create a GUI screen like the one below in-house and see how it actually works.
①Presence Detection and Motion Detection
The register values inside the sensor are read periodically and the actual sensor values are displayed as a graph.
It also displays the detection results inside the sensor.
②Ambient Temperature Shock Detection will not be covered in this column.
③In the "Demo Machine Settings" area of the GUI, the sensor detection threshold and hysteresis can be set individually for Presence Detection and Motion Detection.
Actual operation of STHS34PF80 (TMOS IR sensor) (Part 1)
>We were able to confirm that presence detection was possible even when the person was approximately 2m away from the sensor.
*Motion Detection is not recognized when taking a photo because the camera is stationary, but if you move in front of the sensor, the sensor will send a notification that motion has been detected.
Actual operation of STHS34PF80 (TMOS IR sensor) (Part 2)
The figure below shows the results when you continue to move your hand from a distance of about 1m from the sensor.
The graph appears wavy because the hand is moving at regular intervals.
Also, since the hand is moving, we can see that motion detection is also working.
The graphs on the GUI and the detection results are designed to display the register values inside the sensor directly, making it easy to understand what is happening inside the sensor.
Summary
This time, I used the STHS34PF80 (TMOS IR sensor) and was able to easily confirm its operation because the STMicroelectronics STHS34PF80 can detect objects up to 4m away without using a Fresnel lens and can acquire data via an I2C interface.
Since we did not go into detailed register settings this time, we plan to explain the source code and other details in future columns.
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Additionally, NEXTY Electronics' development team utilizes the products it handles to carry out in-house development and contract development (hardware and software development).
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