ernestmyname
Member level 1
I will be using a thermistor to measure temperature with a microcontroller. I plan to use the controllers 10 bit ADC. I want to display the temperature to tenths of degrees so I need the resolution to be as high as possible.
The chip will be powered by 5 volts. Without any other circuitry, by using a common voltage divider, I can get a 2.4 volt difference between the min and max temperature. The voltage range with a voltage divider circuit with maximum voltage swing is 2.01-4.41 volts measured at the ADC.
Would it be better to use a current source circuit rather than using the 5V from the uController? I will only be checking the voltage every two seconds to prevent excessive thermal heat from the temperature readings. Or what would be the best way to scale 2.01V-4.41V to 0-5V? I would like to measure multiple sensors which will have different voltage ranges. So I would rather not change Vref of the controller for each one. I considered using the thermistor in an opamp circuit to vary the gain. I am eager to hear how you guys would approach this problem.
Thanks in advance!
I may use this thread to post my progress. I will be using SPICE modeling to simulate before I build anything.
The chip will be powered by 5 volts. Without any other circuitry, by using a common voltage divider, I can get a 2.4 volt difference between the min and max temperature. The voltage range with a voltage divider circuit with maximum voltage swing is 2.01-4.41 volts measured at the ADC.
Would it be better to use a current source circuit rather than using the 5V from the uController? I will only be checking the voltage every two seconds to prevent excessive thermal heat from the temperature readings. Or what would be the best way to scale 2.01V-4.41V to 0-5V? I would like to measure multiple sensors which will have different voltage ranges. So I would rather not change Vref of the controller for each one. I considered using the thermistor in an opamp circuit to vary the gain. I am eager to hear how you guys would approach this problem.
Thanks in advance!
I may use this thread to post my progress. I will be using SPICE modeling to simulate before I build anything.