IoT_IO1_3 Getting familiar with Hardware - Sensors.pdf
- 1. Lectures on IoT © IOT-OPEN.EU Consortium Project Ref. 2016-1-PL01-KA203-026471
- 2. Erasmus+ disclaimer This project has been funded with support from the European Commission. This publication reflects the views only of the author, and the Commission cannot be held responsible for any use which may be made of the information contained therein.
- 4. Sensors •Electronic element or subsystem used for detecting the environmental parameter.
- 5. Light Sensors •LDR – Light Dependent Resistor •Photodiode •Phototransistor •Photovoltaic cell
- 6. • P-N junction (PIN photodiode) • Photoconductive mode – reverse biased, changes the current. • Photovoltaic mode – zero bias, generates voltage • Avalanche photodiode – increases current by reaching avalanche breakdown reverse voltage. Photodiode
- 7. Phototransistor •Base-Collector junction - photodiode •Light generates base current •Transistor amplifies this current •Slower than photodiodes
- 8. LDR •High resistance in the dark – MΩ •Low resistance in light – hundreds of ohms •Build with semiconductor but not a P-N junction •Slower than photodiodes •Temperature sensitive
- 9. Thermistor •NTC (Negative temperature coefficient) • Decreases resistance while temperature raises •PTC (Positive temperature coefficient) • Increases resistance while temperature raises
- 10. Hall effect sensor •Varies its output voltage in response to a magnetic field.
- 11. MEMS sensors • Microelectromechanical sensor •Magnetic field sensors •Accelerometers •Gyroscopes •IMU (inertial measurement unit) •Analog or digital output
- 12. Air pressure •Pressure and temperaturę •I2C interface
- 13. GPS •Global Positioning System •NMEA protocol •UART interface
- 16. Reading sensors •Analog • Built-in ADC •Digital • Switch • TWI (I2C) • SPI • One-wire • UART
- 17. The end ;)