Using the STK502 Top Module
2.7 | Sensor | Figure 2-16.NTC-thermistor |
STK502 includes a two screw-terminal block where a sensor can be connected. The STK502 kit is shipped with a NTC-thermistor attached to this screw-terminal. A NTC- thermistor is characterised by the fact that when the temperature goes down the resis- tance goes up. Using a voltage divider and reading the voltage over the thermistor through the ADC-channels on ATmega169, the temperature can be calculated. Applica- tion note “AVR064: STK502 – A Temperature Monitoring System with LCD Output” describes the details of the application.
2.7.1Sensor Switches Two switches on the STK502 are used to connect the sensor to the ADC-channels on the ATmega169 as shown in Figure 2-17.
Figure 2-17.Temperature sensor switches
