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pt100 [2017/03/20 15:27]
216.98.56.20
pt100 [2019/02/22 04:01]
50.25.223.35 Cleaned up phrasing/grammar, added some missing articles.
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-A [[https://​en.wikipedia.org/​wiki/​Resistance_thermometer|PT100]] is a commonly used RTD. Compared to how Thermistor class works - it handles ​NTC'​s ​PT100 is PTC so the change in resistance with temperature is "other way around"​. PT100 also have very different curve than NTCs handled by Thermistor class.+A [[https://​en.wikipedia.org/​wiki/​Resistance_thermometer|PT100]] is a commonly used RTD. Compared to NTC (the most common) thermistors work, the PT100 is "PTC" ​so the change in resistance with temperature is "other way around"​. ​(PT100'​s ​also have very different curve than NTCs handled by Thermistor class.)
  
-PTC means positive temperature coefficient so electrical resistance increases with raising temperature. They cannot be used as-is, you must use an amplifier circuit so they become usable by SmoothieBoard. +"PTC" ​means "positive temperature coefficient" ​so electrical resistance increases with raising temperature. They cannot be used as-is, you must use an amplifier circuit ​to raise the voltage change ​so they become usable by SmoothieBoard.
- +
-**NOTE: This is currently not in the pre built binaries, you would need to git pull and compile to use it.**+
  
 Currently Smoothie only supports E3D's PT100 amplifier board. Other PT100 amplifiers may be supported later (i.e. MAX31865 via SPI). Currently Smoothie only supports E3D's PT100 amplifier board. Other PT100 amplifiers may be supported later (i.e. MAX31865 via SPI).
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 </​callout>​ </​callout>​
  
-You wire a PT100 //almost// the same way you would a thermistor, but you need to specify Smoothie it is a PT100 and where you connected the amplifier signal output:+You wire a PT100 //almost// the same way you would a thermistor, but you need to specify ​to Smoothie it is a PT100 and where you connected the amplifier signal output:
  
 <​code>​ <​code>​
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 temperature_control.hotend.e3d_amplifier_pin ​  ​1.30 ​       # must be a free ADC pin, not a temperature input temperature_control.hotend.e3d_amplifier_pin ​  ​1.30 ​       # must be a free ADC pin, not a temperature input
 </​code>​ </​code>​
 +
 +<callout type="​info"​ icon="​true">​
 +When using a PT100 sensor type you do not need to set values for the thermistor kind or thermistor_pin. If you do, these values will be ignored.
 +</​callout>​
  
 <callout type="​danger"​ icon="​true">​ <callout type="​danger"​ icon="​true">​