• Sensors List

    peter jansen • 08/14/2016 at 21:18 • 2 comments

    Categories:

    Atmospheric (Temperature/Humidity/Pressure)

    • Bosch recently released the BME280 sensor, following their line of popular barometric pressure sensors like the BMP085. The BME appears to integrate temperature, humidity, and pressure into a single low-cost sensor. Sparkfun and Adafruit have breakout boards for about $20.
    • Note: A continuing issue that I've experienced when using atmospheric sensors is that the device they're connected to tends to warm them up, and make at least the temperature readings inacurrate. Thermally decoupling these from whatever device they're connected to is non-trivial and challenging.

    Magnetic Fields

    Non-contact temperature/Thermal Imaging

    Non-contact temperature:

    • The Melexis family of sensors (like the MLX90614) have been the standard non-contact temperature sensor for many years. These are beautiful sensors, tend to have extremely detailed datasheets, and come in a variety of options including voltage and field-of-view. Easy to come by, many tutorials/drivers for various platforms. They tend to be about $10-$25, depending on the model.
    • TI has a new series of thermopile sensors similar to the Melexis sensor, including the TMP006 and TMP007. The TMP007 appears to perform the temperature conversion internally, simplifying use. The field of view is quite large (~90 degrees), where the Melexis line has more options for field of view. Adafruit has a TMP007 breakout. A breakout tends to be around $10.

    Imagers:

    • The FLIR Lepton is a small thermal camera module with an 80x60 resolution for about $300, which is a really enabling price point. Sparkfun has a FLIR Lepton breakout , and example software has been written to work with the Raspberry Pi. When I used this there were some reliability issues, and odd resolutions (e.g. taking the camera out of the socket *while running*). The FLIR Lepton appears to be used in many products that interface with smartphones to provide low-resolution thermal imaging capability.
    • Melexis also has a low-resolution option, the MLX90621, which is a 16x4 pixel array with an I2C interface, for about $50.
    • Panasonic has the GridEye range of sensors, which is another low-resolution imager option at 8x8, also has an I2C interface, and seems to be about $25 in single quantity. The temperature range appears to be lower than the MLX90621. When I tried to order one from Digikey for evaluation, it required odd paperwork with export restrictions, so I did not pursue it further.

    Gas Sensing/Atmospheric Particles

    • Bosch appears to be extending their BMP280 temperature/pressure/humidity sensor with the BMP680, which will also include an indoor volatile organic compound (VOC) gas sensor.

    Air Quality/Particles:

    • An article in Make Magazine, Air quality sensors: How good is good enough? compares two inexpensive sensors with a professional instrument, showing generally good agreement in specific cases, and outlining some of the issues in gas sensing.
    • The Shinyei particle sensors appear to be inexpensive optical-based sensors, and are discussed in the Make article. They're also appear to be a little bulky for handheld devices (~5x6x2cm), so projects with these appear to make desktop systems.
    • The Sharp GP2Y1010AU0F appears to be similar to the Shinyei sensor, and is of a simliar size. This is available from Sparkfun for about $12, though one of the comments mentions they can be found on eBay with wiring harnesses that simplify connection.
    • The Maxim MAX30105 is a new sensor...
    Read more »