In this section, we are showing how to use DS18B20 one wire water proof thermometer.
E. coli is temperature sensitive. According to the experiment, it grows the best in 37°C (99°F), and its acceptable range is about 22°C to 40°C (72°F to 104°F). Therefore, we need a thermometer to monitor the medium's temperature to ensure the E. coli works well in the reactor.
- Experiment 1: Temperature measuring
- As the buffer solution wouldn’t change too much in the environment, we used the buffer solution to calibrate the pH meter to ensure that the deviation would be the same every time.
- We put our thermometer into the incubator. We wire the sensor with the LCD to keep it closed.
- We placed the sensor in an environment of incubator 37 degrees celsius, and the temperature measured by the LCD display sensor was 37.06 degrees celsius. The error is 0.06 degrees celsius, which we think it's not a big error. But in order to make the measure temperature more accurately, we designed Experiment 2 - Temperature experimental curve fitting.
- Since the error value of the temperature sensing device is not necessarily, we use multiple sampling methods, and then average the values measured in each temperature interval to reduce the error value without excessive error.
- We use the above method to take 150 strokes as training data, and use the basic accessories of MATLAB to find the appropriate nine temperature model formulas.
- We found a temperature curve of 7th order to reduce its error. (You can see more information in software temperature.)
- Arduino UNO
- DS18B20 thermometer
- Power supply range is 3.0V to 5.5V
- Measures temperatures from -55°C to +125°C (-67°F to +257°F)±0.5°C accuracy from –10°C to +85°C (14 to 185°F)
- a register of 4700 ohms
- Arduino Code
- Konstantin Dimitrov.(2016).Arduino Thermometer With DS18B20. Retrieved from https://create.arduino.cc/projecthub/TheGadgetBoy/ds18b20-digital-temperature-sensor-and-arduino-9cc806