Sensors.

A short overview over sensors

NOTE: MQ gas sensors can be found at mq.html

Measuring temperature.

This can be carried out in several ways

1. NTC resistor(analog) (a resistor with negative temperature coefficient - typical uses in voltage divider configuration

   1. Set up a voltage divider, measure voltage, do some math

   2. See here for more info

2. LM35(analog)

   1. 55C - 150C

   2. see more here

3. DS18B20(digital) - A sensor where you have have many of them in parallel over 3 wires: ground, Vcc, comm

   1. elegant for measuring many temperatures from one unit

   2. can be found as to

   3. might be regarded as slow compared to NTC.

   4. https://randomnerdtutorials.com/guide-for-ds18b20-temperature-sensor-with-arduino/

4. DHT-11, DHT22(digital) a combined sensor measuring temperature and air humidity

   1. DHT11 20-90% rel humidity 5% rel, 0-50C +-2C

   2. DHT-22 0-99.9% rel humidity 2-5% accuracy, temperature -40-80C +-0.5C accuracy

   3. comparison here

5. BMP05 / BMP280 (digital) combined temperature and air pressure sensor

   1. bmp280 Arduino SW with drivers and examples

   2. bmp085 Arduino SW with drivers and examples

Measuring humidity.

copy paste from temperature above

1. DHT-11, DHT22(digital) a combined sensor measuring temperature and air humidity

   1. DHT11 20-90% rel humidity 5% rel, 0-50C +-2C

   2. DHT-22 0-99.9% rel humidity 2-5% accuracy, temperature -40-80C +-0.5C accuracy

   3. comparison here

Distance

Many uses the ultra sound range measure sensor SR-04

Works from 4 cm up to several meters.

It uses ultra sound See

• https://www.instructables.com/Arduino-Ultrasonic-Sensor-HC-SR04/

  • data sheet

  • my humble small example

Atmospheric pressure, temperature and altitude

Physical movement detect - IMU boards

Inertial measurement unit(IMU) do measure acceleration and rotation for a device - like satellite, car etc

See

• https://jensd.dk/space/cansat/tryk.html on way

Hall sensors - mag field

• https://www.sparkfun.com/sparkfun-linear-3d-hall-effect-sensor-tmag5273-qwiic.html

• https://www.sparkfun.com/sparkfun-mini-linear-3d-hall-effect-sensor-tmag5273-qwiic.html

They do all have

• a barometric sensor (air pressure and temperature) normally from Bosch: BMP085,180,280

• an acceleration and rotation sensor MPU606x or MPU9250

• mag field sensors - they are rather unprecise so no more about them.

/ Lot of cansat litterature at https://jensd.dk/cansat2/candocu.html

• https://jensd.dk/doc/sensors/gy/

imushield

gy80,87,88 IMU boards

IMU boards gy80, gy87 and gy88 including arduino libraries See

• gy

Always under construction

Jens

THE BEER-WARE LICENSE (Revision v 42) jensd@jensd.dk wrote this file.
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If we meet some day, and you think this stuff is worth it, you can buy me a beer in return :-)
(C) Jens Dalsgaard Nielsen
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