i (tried) to build a Project to control my destillery (especially the heat source).
It should show the actual temperature comming from a DS18B20 and show it in the Display.
i use two buttons to rise and lower the maximum temperature (to wich i try to heat the destillery)
the code controls a relay, which sould simply turn on and off the heat source to rise the temp and go off on maximum temperature.
the second Temperature (pt100)is for a emergency shutdown to measure the water in the cooler. if it goes to high it turns off the heater, and make some noise (relay two).
No to the actual problem(s):
the sensorvalue i get from the pt100 is not stable(converted in degrees C it goes up and down for like 2-3), and i cant tell why. i can live with that for the emergancy shutdown, but not for the exact temp on the distillery itself. anyway it should not be this way… :
all the rest worked fine for like 2h, than turned into a gremlin… which leads me to
every then and now, i get 85 degrees from the ds18b20, which means (so far i read) it is not connected well, what simply cant be… its rock solid and i can mesure the whole way throug with my multimeter without any issue. sometimes no issue for like 1h or more sometimes all the time. sometimes it flaps to 85 and back to normal.
the code itself (so far i testet the 2h in line) works, what makes me think the gremlin is somewhere in my elektronics/ the way i wired it up.
i tried to sketch it in fritzing as good as i could (pic below).
Can anybody tell me what i did wrong, to tame this monster back to normal?!?!