Wednesday, January 9, 2019
So far we have the temperature sensor working but we don't have the conductivity probe "working". When we run the conductivity probe we receive "no data". Mr. Meinersmann and I have a few ideas of what is happening and why. We are working on figuring it out more tomorrow.
This is a resistor chart. It tells you what each band on the resistor means.
I started with the 10k resistor and it was giving me a temperature, not even close to being accurate. The 10k resistor gave us a temperature of 85º c. Mr. Meinersmann and I read about the temperature sensor. It said that you need to use a 4.7k resistor. The 4.7k resistor gave us 18ºc. That was about the temperature in the room so we still have to calibrate it, but at-least it is close.
The readout of 4.7 is from the temperature sensor with the 4.7k resistor on.
10 is the temperature sensor reading with the 10k resistor on.
January 22, 2019
The past few days we have been working on getting the temperature sensor on the shield. Where the red is circles are the are two rows on each side that are ground and 5 volts & 3 volts. In my previous shields I soldered things in those rows and it short circuited and failed. Last week I noticed the row with 3 volts. So I solder the temperature sensor to the shield, it did not work because I soldered a wire from the row of 3 volts to the 5 volt pin on the shield. However, I did not noticed the row with 5 volts until Mr. Meinersmann pointed it out to me.
January 25, 2019
Today Mr. Meinersmann and I combined code to log the temperature readings to the SD card. We combined the sample logging code with our temperature sensor code. First, we went through the sample code for logging the data. After we went through the sample code, we slowly moved the parts of the code that we needed to the temperature sensor code. Success, but tempC, stamp, and datetime were in the wrong spot. We will need to fix that, but that should be quite easy.
January 29, 2019
Today we learned that we can get more than one reading from the conductivity sensor. We can get the conductivity sensor working. However to get it to work correctly we need a correct temperature so it does not assume the temperature. The next thing we are going to do is calibrate the temperature sensor, in order to get the conductivity sensor working and calibrated.
Here is the code we are using:
Here is my reference https://www.instructables.com/id/Calibration-of-DS18B20-Sensor-With-Arduino-UNO/
We did not do everything from our reference, we are going to use a pot of boiling water, we need to put the temperature sensor int the water without touching anything else for a few minutes. Then read the serial monitor, the temperature we read for the last minute is the raw high value, write it down for reference. Next we need a big glass of ice water and do the same but instead of the raw high value it is the raw low value, write it down for reference. The we subtract the raw
And tomorrow we will attempt to calibrate the temperature using the method outlined here. The calibration of the temperature sensor. first we dunked the temperature in ice water and the temperature is the raw low (0.25) , then we dunked it in boiling water to get the raw high (99.69).
It is working and calibrated!!!! Last week we made huge progress we got the conductivity probe working in addition to the temperature sensor. Then we calibrated, I explain the conductivity calibration in the video bellow.