Introduction


This page describes how to setup external Temperature sensor using a Revolution, Revolution Nano, or Sparky2 board, to be used as HoTT sensor.

Two temperature sensor can be connected to a ADC port :

  • LM35 sensor, up to around 100°C
  • NTC sensor, up to 300°C






Hardware


LM35 sensor

Connections are pretty simple: Gnd, +5V, and analog voltage proportional to the temperature (usually 0.01V/°C) back to the ADC pin.

The sensor can be connected to various ports, according to the board you use. See next part.






NTC sensor

NTC can be connected to the ground or to the 3.3V voltage reference and following settings will be adjusted with the values used.

The sensor can be connected to various ports, according to the board you use. See next part.






Select the analog input


Go to System > UAVOBrowser > Settings > HwSettings > ADCRouting and select the adc input pin used for temperature function (LM35Temperature or NTCTemperature).

Preferred adc input pins are located on Output ports, using a servo connector.

Here is the adc mapping for various boards:

Boardadc0adc1adc2adc3adc4adc5adc6
RevolutionPWR port
pin 3		PWR port
pin 4		Output port
out 3

Output port
out 4

Output_port
out 5

Output port
out 6

internal
Sparky2PWR port
pin 3		PWR port
pin 4		PWR port
pin2

Output port
out 3

Output port
out 4

Output_port
out 5

Output port
out 6

RevoNano

FlexiIO
pin 4

FlexiIO
pin 5		FlexiIO
pin 6		FlexiIO
pin 7		FlexiIO
pin 8		Output_port
out 5		Output port
out 6

FlexiIO refers to the receiver port






Calibrate sensor

LM35 calibration

At this point you can do some measurements and compare a LM35 temperature readings found into the TemperatureState UAVO with the ambient temperature.

A LM35 will not need calibration since his output is factory calibrated for 0.01V/°C.

NTC calibration

NTC sensor type may need some calibration according to:

  • the reference voltage need to be stable
  • NTC datasheet: beta value, nominal value at xx°C
  • serial resistor value

Temperature1 refers to the LM35 temperature and Temp2 to the NTC measured temperature.