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Ntc thermistor sensor

By Resmey Mom Pierre-Marie Meyitang Aung Paing Soe. Ntc thermistor sensor. Arduino (Microcontroller). Duemilanove- ATMega168 . 14 digital/analog I/O 10 bits - 1024 levels Flash Memory – 16KB SRAM – 1KB EEPROM – 512 bytes Clock Speed – 16 MHz

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Ntc thermistor sensor

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  1. By Resmey Mom Pierre-Marie Meyitang Aung Paing Soe Ntc thermistor sensor

  2. Arduino (Microcontroller) • Duemilanove-ATMega168. • 14 digital/analog I/O • 10 bits - 1024 levels • Flash Memory – 16KB • SRAM – 1KB • EEPROM – 512 bytes • Clock Speed – 16 MHz • External Supply range from 0V to 12V (recommended) • 5.044V supply from USBport.

  3. Software (Windows) • Automatically downloads driver updates. • http://arduino.cc/en/Main/Software

  4. Program Code • Based on C/C++ Languages. • http://www.arduino.cc/playground/ComponentLib/Thermistor2 • Input: • Analog voltage reading • Output: • Voltage (Volts) • Resistance (Ohms) • Temperature (Celsius + Fahrenheit)

  5. #include <math.h> double Thermistor(int RawADC) { long Resistance; double Temp; Resistance=((10240000 /RawADC) - 10000); Temp = log(Resistance); Temp = 1 / (0.0013269299 + (0.0002557825582 * Temp) - (0.000000009462253908 * Temp * Temp * Temp)); Temp = Temp - 273.15; //Convert Kelvin to Celsius temp = (temp * 9.0)/ 5.0 + 32.0; // converts °C to Fahrenheit Serial.print(1024-RawADC); Serial.print("/1024"); printDouble((((1024-RawADC)*5.044)/1024.0),3)

  6. NTC Thermistors • Steinhart and Hart Equation: • T: Temperature in Kelvin • R: Resistance of Thermistor in Ohms • 3 Coefficients: A, B, C • Example Calculations: 1. 2. 3. Solve for the equations simultaneously to get A, B, C Our Final Equation:

  7. ADC and Resistance Equation • Vchange = (5.044V) = 5mV(smallest step) • ADC = ; V10k = ADC x Vchange • V10k = *ADC = (5.044V) (Voltage Divider) • = • R = – 10k R = Thermal Resistance

  8. Outcome Next Step • Teamwork skills • Temperature-Thermal Resistance relation • Microcontroller • Analog to Digital Conversion • Simple Applications • CPU Fan controller • HVAC controller • Digital Thermometers, etc. • CPU Fan controller • Senses Temperature • Controls the fan speed • User friendly design • HVAC controller • Sense Temperature • User Temperature Set • Shuts off Heater or A/C

  9. References http://www.arduino.cc/en/Main/ArduinoBoardDuemilanovehttp://www.arduino.cc/playground/ComponentLib/Thermistor2http://saturn.uni-mb.si/~dogsa/ne/gradivo/NTK-termistor.pdfhttp://www.ametherm.com/thermistor/thermistor-steinhart-hart.html

  10. THANK YOU!!!! ANY QUESTIONS? Contact Emailsmomr@wit.edumeyitangp@wit.edusoea@wit.edu

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