Does anyone have an understanding of the wixel temperature sensor? I want to know how to convert the reading from the temperature sensor to Celsius or Fahrenheit or Kelvin for that matter. I get a reading of 513 at about 73 F but want to know what the 513 represents. Is 513 a millivolt reading ? Not so sure how to translate that into a temperature. Thanks ahead of time for any suggestions…
Hello, lucutis.
Where are you getting the number 513 from? If you are calling adcRead(14) then the units returned are documented here:
pololu.github.com/wixel-sdk/adc_ … c3a0cf1789
A reading of 0 represents a voltage of 0 V while 2047 represents 3.3 V.
However, the sensor’s output will always be under 1.25 V so you should read it using the internal 1.25 V reference to get more resolution and reliability:
adcRead(14 | ADC_REFERENCE_INTERNAL)
Then a reading of 0 represents a voltage of 0 V while 2047 represents a voltage of 1.25 V.
The CC2511’s temperature sensor is documented in the CC2511’s datasheet, Section 6.9:
focus.ti.com/docs/prod/folders/p … 11f32.html
A sensor output of 848 mV represents 40 Celsius and the temperature coefficient is 2.43 mV/degreeC
With a some algebra you should be able to come up with a linear formula that converts an ADC reading to degrees Celsius. Let me know if you want help doing this.
–David
Thanks everyone! You were a great help! Mark