Futterama
Member
Hello forum,
I would like some help on this project: I wish to measure a temperature, range from 0°C to 150°C.
The temperature probe should be a small thermistor (perhaps NTC), and I wish to use a PIC12F683 with internal 10-bit AD-converter and 256byte EEPROM.
The PIC will run from 5V, and I have some precision voltage references for this project (MAX4050 4.096V 0.1% reference and Zetex ZR431)
The overall precision should be +/-1°C.
I plan on putting the thermistor on a hot surface (150°C) and read the ADC value of the PIC for every degree as the hot surface cools down, and note these values, and program them into the EEPROM of the PIC for lookup when operating.
But I think I need some help with the circuit. I've read on this forum that 2.5k is tha largest acceptable impedance for the PIC ADC to keep ADC accuracy...
So, I need help on choosing the right thermistor, and building the circuit.
Thanks.
Regards,
Futterama
I would like some help on this project: I wish to measure a temperature, range from 0°C to 150°C.
The temperature probe should be a small thermistor (perhaps NTC), and I wish to use a PIC12F683 with internal 10-bit AD-converter and 256byte EEPROM.
The PIC will run from 5V, and I have some precision voltage references for this project (MAX4050 4.096V 0.1% reference and Zetex ZR431)
The overall precision should be +/-1°C.
I plan on putting the thermistor on a hot surface (150°C) and read the ADC value of the PIC for every degree as the hot surface cools down, and note these values, and program them into the EEPROM of the PIC for lookup when operating.
But I think I need some help with the circuit. I've read on this forum that 2.5k is tha largest acceptable impedance for the PIC ADC to keep ADC accuracy...
So, I need help on choosing the right thermistor, and building the circuit.
Thanks.
Regards,
Futterama