Sensor module

(Version 5.1)

Sensor module includes the combined board of sensors, low-pass filter and external sensors.

Sensor module features

  • Electret microphone
  • Light intensity sensor (photoresistor) VT935G (resistance 18,5 kΩ on 10 lux) datasheet
  • Temperature sensor (thermistor NTC) (resistance 10 kΩ on 25 °C) datasheet
  • Potentiometer 10 kΩ
  • Ultrasonic distance measure sensor Devantech SRF05 with cable (measuring distance 1-400 cm) datasheet
  • Infrared distance sensor Sharp GP2Y0A21YK0F (measuring distance 10-80 cm) datasheet

Electrical connections

On-board sensors are connected as follows:

on-board notationexternal notationon-board sensormicrocontroller port
MICAD0MicrophonePF0
LDRAD1Light intensity sensorPF1
NTCAD2Temperature sensorPF2
POTAD3PotentiometerPF3

Sensors

Every sensor on the board is connected through the multiplexer, enabling to select between on-board sensor or external sensor which can be connected to the same port through the connectors. By default all on-board sensors are connected to the analogous inputs of the microcontroller (ADC0-ADC3). Multiplexer is controlled with the port PG0.

Schematics of multiplexer
Schematics of sensor connections

Low-pass filter

Low-pass filter can be composed between external analogous inputs 0-3 (PF0-PF3). Resistor and capacitor will be connected to the socket for building up the low-pass filter. By default a low-pass filter is composed for the channel 0 (PF0). Resistor value is 10 kΩ and capacitor value is 100 nF.

Schematics of external sensor connections and low-pass filter

Digital I/O connector

In addition to the sensors and analog inputs, there is a connector for digital I/O on the board. The pins of the connector are directly connected to pins PE2-PE5 of the controller.

The D_IO connector
en/hardware/homelab/sensor/v51.txt · Last modified: 2018/12/27 12:53 (external edit)
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