Welcome, Guest

Author Topic: What thermistor is on the PIC-MAXI-WEB?  (Read 1441 times)

toozie21

  • Newbie
  • *
  • Posts: 19
  • Karma: +0/-0
What thermistor is on the PIC-MAXI-WEB?
« on: March 13, 2014, 01:53:47 AM »
I am looking to pick up the PIC-MAXI-WEB, but I can't figure out what thermistor is on there (I want to make sure it will work for my application).  The schematic doesn't call out a part number for me to look up a datasheet for.  Does anyone know what part that is?

LubOlimex

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 1949
  • Karma: +50/-3
Re: What thermistor is on the PIC-MAXI-WEB?
« Reply #1 on: March 18, 2014, 10:01:17 AM »
It is NTC103 10k. The B parameter is 4100.

There is plenty of info about such thermistors if you search the web. The part of the code responsible for the measurement is the blow one:
 
Code: [Select]
HTTPPrint_temp(void)

...
   
    r = ((1024.0*10000.0)/(float)tmp)-10000.0;
    // B parameter equation - B = 4100
    temperature = 4100.0/log(r/0.0111182) - 273.15;
 
    itoa(temperature, TempString);

...
}

We had to improvise with the B parameter equation a bit (http://en.wikipedia.org/wiki/Thermistor) because the board was using too much memory initially.

Best regards,
Lub/OLIMEX
Technical support and documentation manager at Olimex

toozie21

  • Newbie
  • *
  • Posts: 19
  • Karma: +0/-0
Re: What thermistor is on the PIC-MAXI-WEB?
« Reply #2 on: March 20, 2014, 02:55:14 AM »
Awesome, thanks so much!