since I have no luck in another thread (https://community.nxp.com/message/764698), I want to ask my question in a different way.
I do use an LPC11U68 on an Xpresso V2 Rev C
The data sheet and manuals say that there is an 12bit ADC.
The internal temperature sensor is connected to channel 0 when powered up.
The sensor measures the temperature inverse to the ADC value.
The temperature range is from -40 to 105°C.
I get a raw ADC value of about 650.
So I calculate:
const constexpr std::int32_t maxRawValue = 4095; //12bit ADC
const constexpr std::int32_t temperatureRange = 145;
const constexpr std::int32_t temperatureOffset = 40;
const std::int32_t rawValue = getRawValue();
const std::int32_t invertedRawValue = maxRawValue - rawValue;
const std::int32_t result = (invertedRawValue * temperatureRange / maxRawValue) - temperatureOffset;
My result is than -17.
When I use some coolant spray, the rawValue will not change much.
Does anybody have some suggestions what I could do wrong?
Thanks a lot!
PS: I get correct ADC values when I turn off the internal temperature sensor and do connect a potentiometer.