Adafruit forums user EasternStarGeek posted some great new code for our 10K Precision Epoxy Thermistor.
My approach differs slightly in that I use a lookup table instead of the logarithmic formula given in the Adafruit tutorial. I didnt make any measurements, but it could very well run faster, since it doesn’t depend on a lot of complex floating-point math. In any case, Lookup tables are useful sometimes, and my example not only shows how to do a lookup, but also how to interpolate between the two closest entries to the measured value.
You will also find a helper spreadsheet that was used to create the LUT used in the sketch, along with some interesting charts that show graphically, the relationship between temperature and thermistor resistance, as well as temperature versus ADC voltage.
Need to measure something damp? This epoxy-coated precision 1% 10K thermistor is an inexpensive way to measure temperature in weather or liquids. The resistance in 25 °C is 10K (+- 1%). The resistance goes down as it gets warmer and goes up as it gets cooler. For specific temperature-to-resistance, check the lookup table.
These are often used for air conditioners, water lines, and other places where they can get damp. The PVC coating of the wires is good up to 105 °C so this isn’t good for very hot stuff.
We even toss in an additional 1% 10K resistor which you can use as calibration or for a resistor divider.
Adafruit publishes a wide range of writing and video content, including interviews and reporting on the maker market and the wider technology world. Our standards page is intended as a guide to best practices that Adafruit uses, as well as an outline of the ethical standards Adafruit aspires to. While Adafruit is not an independent journalistic institution, Adafruit strives to be a fair, informative, and positive voice within the community – check it out here: adafruit.com/editorialstandards
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.
Have an amazing project to share? The Electronics Show and Tell is every Wednesday at 7pm ET! To join, head over to YouTube and check out the show’s live chat – we’ll post the link there.
There seems to be a disconnect between the forum post and the blog post and the blog title. On the one hand there’s talk about thermistors, on the other hand there’s the DS18B20 which is not a thermistor in any way.
There seems to be a disconnect between the forum post and the blog post and the blog title. On the one hand there’s talk about thermistors, on the other hand there’s the DS18B20 which is not a thermistor in any way.
I think the product the forum post is referring to is the waterproof 10k thermistor.
http://www.adafruit.com/products/372
Thanks for catching that Stephanie! Fixed.