Imagine: it’s almost Halloween. You want to create a very interesting experience for people who make trouble without candy. In this digital age, setting up pumpkin lanterns and tombstones on the lawn seems not enough. You need movement, just like electronic animation, it will jump when someone walks by! Biological movement based on some corresponding actions can be realized through a variety of controller trigger technologies, including pressure sensing pad, manual operation button and beam sensor.
Similarly, if you want to ensure the safety of a large room, you need to put your “eyes” in all corners and parts of the space. For safety reasons, the traditional way to obtain such a wide view of the room is to install multiple cameras or motion detection alarm sensors, but this will involve a more complex system integrating multiple feeds.
Fortunately, today’s presence sensing technology makes it easier to create vivid and mobile Festival displays, let alone more powerful security systems. Infrared (IR) array sensors enable the system to detect not only the presence of someone, but also their direction of movement. The technology can also be used in thermal imaging, night vision and medical imaging.
How does Star Wars promote the development of intelligent sensors
Encouraged by the US Strategic Defense Initiative (SDI), smart sensors began to appear on the market. In 1983, then President Ronald Reagan publicly announced that SDI, nicknamed “Star Wars”, was proposed as a missile defense system to protect the country from ballistic nuclear weapons. Smart sensors now play an indispensable role in security and other intelligent interconnected systems, also known as the Internet of things (IOT). By integrating sensing, signal extraction, processing and understanding, smart sensors provide the intelligence needed for these applications to be effective. By the late 1990s, with the decline of the cost of uncooled array and the continuous progress of technology, the use of infrared technology began to be more used for military and civilian purposes (such as automobile anti-collision system, medical diagnosis and environmental control).
Uncooled infrared sensor technology continues to progress, especially with the emergence of pixel structure based on microelectronic system (MEMS). Here, the independent thermal isolation structure of thin film infrared absorber is adopted. Using this technology, you can develop a system to measure radiant power to determine the temperature of an object (or body) remotely. Using today’s semiconductor technology, we can develop thermopile sensors composed of hundreds of thermocouples of several square millimeters. This type of sensor is very sensitive, small in size, fast in response time and relatively cheap, so it is very suitable for consumer equipment, medical instruments, safety systems, population statistics, building automation, etc.
Panasonic provides grid eye ® 8×8 thermopile array. This 64 pixel infrared sensor is suitable for reflow compatible surface mount (SMD) package, which is composed of RF shielded metal cover, MEMS sensor chip, digital ASIC with I 2C interface and silicon lens. Infrared energy passes through.
In operation, the grid eye first absorbs the emitted heat energy within a 60 degree field of view. Each of the 64 sensing elements of the array converts its absorbed heat energy into a proportional output signal. Then amplify all 64 temperature signals, convert them from analog to digital, refer to the ambient temperature value provided by the thermistor, and then transmit them from the sensor to the microprocessor. Eric johnsrud, an expert in Panasonic sensor technology products, explained that the microprocessor then performs calculations to map the temperature from a single thermopile element to a complete thermal representation of the entire field of view. From this thermal representation, the position and existence of moving people and objects and stationary people and objects can be detected,
Panasonic grid eye is an 8×8 thermopile array that can operate in both horizontal and vertical directions.
Panasonic’s grid eye can work in horizontal and vertical directions. The recommended maximum detection distance is 7m and the frame rate is up to 10 FPS. To learn more about thermopile arrays and grid eye, Download thermopile arrays to open a new world of automation applications.
Extending I2C using 1-wire bus
Another way to extend the I 2C bus distance (and operate above the maximum allowable bus capacitance) is to operate at a lower speed, use a higher drive output device, divide the bus into segments with bus buffers, or use a switch pull-up circuit. However, these methods usually either fail to meet the long-distance requirements or add a lot of cost to your design. Efmaxr design reference # attached # ® mbed ™ And Arduino platform, as well as schematic diagram, layout file, Fab file and bill of materials (BOM).
Modern traditional building control system
Building automation applications such as energy, lighting and temperature control can also benefit from IR sensor technology. For example, the ability to detect when someone enters a room can trigger the lights to turn on and the HVAC system to adjust to the preferred temperature. In order to help designers integrate traditional systems with modern control and communication, Maxim provides its building automation expansion board maxrefdes130# reference design. Maxrefdes130 # has a 1-wire main bus and can be used with maxrefdes131 #. Maxrefdes130 # provides Arduino dimension expansion board compatible with arm mbed and Arduino platform. You can prototype various building automation designs.
Whether you are developing ingenious Holiday Themed electronic animated displays, home safety systems or building control designs, intelligent sensor technology can provide the proximity sensing functions required to make these systems effective, which is of value to end users.
Reviewed and edited by: Guo Ting