Temp, Pressure, and Humidity sensors with MCP3204
Hey,
We have three different sensors that are all going to be connected to a MCP3204 a/d. We have a working program that is reading the count values and printing in terminal. Now we're doing basic testing and trying to see how the counts change depending on changing temp, pressure, and humidity.
So far, we've tested the temperature and pressure and here are some questions
1. Temperature - at nominal conditions (not trying to heat or cool the sensor) the count values are fluctuating a lot (2700 to 3500 range). Then we heat and cool the sensor by either holding and then placing near the window, and we don't see a change in value that parallels the change - so it fluctuates in the same range and it does go up or down if we heat or cool.
2. Pressure - at nominal conditions, the count value is fluctuating from 0 to 10. It seems to change if we try to change the pressure (just blowing into the inlet).
What is causing these fluctuations?
Any advice would be great! New to programming, so sorry in advance for incorrect terminology or questions.
Katie
We have three different sensors that are all going to be connected to a MCP3204 a/d. We have a working program that is reading the count values and printing in terminal. Now we're doing basic testing and trying to see how the counts change depending on changing temp, pressure, and humidity.
So far, we've tested the temperature and pressure and here are some questions
1. Temperature - at nominal conditions (not trying to heat or cool the sensor) the count values are fluctuating a lot (2700 to 3500 range). Then we heat and cool the sensor by either holding and then placing near the window, and we don't see a change in value that parallels the change - so it fluctuates in the same range and it does go up or down if we heat or cool.
2. Pressure - at nominal conditions, the count value is fluctuating from 0 to 10. It seems to change if we try to change the pressure (just blowing into the inlet).
What is causing these fluctuations?
Any advice would be great! New to programming, so sorry in advance for incorrect terminology or questions.
Katie
Comments
Just to clarify, low/mid/high range of the voltage?
Sorry, did not mean to be so cryptic. By this I mean that if your adc measures a range from 0 to 2.56 then check the reading from the adc with voltages around 0.05V, 1.28V, and 2.50V. Use a calibrated voltmeter for comparison if possible, and avoid going to the absolute minimum (0V) and maximum (2.56V) to avoid problems caused by under/over range inputs.
I was just about to test the voltages, but I ran the program again the result was
ch 0 : 4095
ch 1 : 4095
ch 2 : 4095
ch 3 : 4095
Nothing is plugged into any of the channels and it's reading maximum count (it's a 12bit resolution, so 2^12 = 4096). Did I break it?