Page 1 of 1

[Nano112] Use ACMP Slope to Measure PT1000

Posted: 18 May 2020, 15:33
by chhsieh3
  • Application: This sample code uses the ACMP slope of Nano112 to measure the temperature of PT1000.
  • BSP Version: Nano102/112 Series BSP CMSIS v3.03.000
  • Hardware: NuTiny-SDK-Nano112V
The Single Slop ADC mode is an analog-to-digital conversion technique to measure unknown resistance and can be implemented with a comparator rather than a standalone
ADC module. The technique is using known and unknown resistor to discharge a capacitor. While the capacitor is discharged, the number of clock cycles counted by timer indicates
resistance ratio. Larger counting number indicates Larger resistance value. The unknown resistance can be calculated based on the discharge time and known resistance.

Only the comparator ACMP0 has Single Slope ADC mode which can implement a low cost but high resolution ADC function by using just a little additional external components.
The external components include a thermistor (e.g. PT1000), a reference resistor, and a capacitor.

You can download the sample code at https://www.nuvoton.com/resource-downlo ... 1227193713