me again. getting 200 mV instead of 230 mV reading. May not be much, but represents 3 Centigrade in my application. What can I do?
Would I need an amplifier, suppose I will get 900mV maxima, so if I amplify it by 3, would be better?
Regards,
Steffen
Is your voltage source the correct impedance for the ADC?
Leon
its batteries, rechargable. Don’t know it this means yes or no to your answer, but its meant to work with batteries.
Put two sensors next to each other so they would read the same and two inputs on ground.
Readings are
0 0 59 57
0 0 55 56
0 0 58 57
0 0 57 56
0 0 55 57
0 0 56 57
0 0 58 57
0 0 57 56
0 0 57 58
0 0 59 57
0 0 60 58
0 0 58 56
0 0 58 57
0 0 56 56
should rather be around 63 for 200mV? Its for room temperatures, bit of a difference between 17 and 20 Centigrade. Its 200mV at the sensors and 200mV at the board, nothing got lost inbetween.
Then again, I want to see daily differences on different spots, say roof versus outside/inside, sub floor, so if the base is the same, means one room always colder than the other. But at the other hands, can I trust my readings?
edit: or do I need pull up resistors? Open input readings are between 550 and 800, should be either 0 or 1024?
or some resistors somewhere else? Its LM35s, on vero board at the moment but going to be on cables to the different rooms.