Maplin doesn't ship to my country, the second thermistor is only for up to 110°C, too less for my hotend. Anyway, I had answered a clear question and had the hope to get an answer to it. I have found an easy solution myself. Just configure the thermistor with any beta value, then heat the hotend up to 230 °C. Now calculate the impedance of the resistor with this formula: r2 = r1 / exp(beta*(by gdachs - Smoothie
Quotethe_digital_dentist Get any 100k thermistor (100k Ohms at 25C) for which the manufacturer provides an R vs T table (just about all of them have such tables in the data sheets). You can use that table to generate Steinhart-Hart coefficients. That is likely to be far more accurate than trying to create your own table from an unknown thermistor. I know this all, why do the people always thinkby gdachs - Smoothie
Yes I have an unknown thermistor. I have looked already for a replacement. The thermistors that are known by smoothieware are not easy to get. And most other thermistors that are cheap have only beta values for temperatures between 0-80°C. A multimeter with a Rin of only 10M Ohms will give me a failure of 1% at 100K of the thermistor at 25°C, this failure gets much less at the more important higby gdachs - Smoothie
@the_digital_dentist: so no possibility to do this? Then I might try to hook the heater directly to 12V and the multimeter directly to the thermistor and make a video . Have only to switch off before it gets too hot. Geraldby gdachs - Smoothie
Thanks for the fast answer. Can you explain why I have to remove it from the "reserved pins" list. What other consequences does this have? I can't find something in the config that would remove the pin from the list, can you help me with this too? Geraldby gdachs - Smoothie
Is there a g code command that allows me to see the current impedance of a thermistor? I want to find the Steinhart Hart coefficients empirically and I am afraid that my multimeter will change the impedance if I measure it parallel to the board, at least at low temperatures. Geraldby gdachs - Smoothie