Real time temperature alarm
Team members
Huang Haowei You Mingkai
Idea
This Project aims to create a system with raspberry-pie and python to real timely monitoring of temperature changes and issuing alerts (sound or text message (only current scenario)） when the temperature exceeds the set threshold
Setup
- raspberry-pi
- temperature sensors
- dupont line
- LED light or Buzzer（finally we choose twilio to send warnings）
Measurements
Connect and install a suitable system environment for Raspberry-Pi
Connect the sensor: Thermistor type B57861S (R0=10kΩ, B=3988Kelvin)
Write Python script: Create a Python script to read and print temperature and humidity data: record temperature data in real-time and visualize temperature trends using charts. Write temperature data to a file or database in a Python script. Use Matplotlib library or other data visualization tools to regularly read data and generate temperature change graphs
Temperature threshold alarm: Purpose: Set a temperature threshold, and when the temperature exceeds this threshold, Raspberry Pi will sound an alarm or perform specific actions. Implementation: Add judgment logic to the Python script. When the read temperature exceeds the set threshold, the GPIO pin of the Raspberry Pi can output a high level, driving a buzzer or LED light as an alarm signal
Results:
1.Real time temperature figure Firstly, we measured the real-time room temperature multiple times at intervals of 5 seconds at a temperature of approximately 22.7 degrees Celsius, and obtained the final image, as shown in the figure: And when the temperature exceeds our set threshold of 24 degrees Celsius, it will be marked with red dots and recorded, and an alarm will be issued.
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2.Warning In the absence of suitable alarm instruments such as LED lights or buzzers (in fact, their alarms are not easy to record in reports), we have chosen another method: sending text messages. This method is more complex to operate but more practical in today's life: receiving warnings at any time. So we registered Twilio and readjusted the experimental Python code based on the virtual number, registration code, verification code, etc. obtained from registration to complete the function: when the temperature exceeds the threshold of 24 degrees Celsius, we use the virtual number to send an alarm short message to the set acceptance number in real time.
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3.Improvement of the experiment: Due to the remaining 2 class hours after completing the post test, we have decided to make an improvement to the experiment: practical application. After excluding resistance wire heating or other hazardous projects that are difficult to carry out in the laboratory, we chose a project with higher practical significance: simulating the greenhouse effect (which can provide some ideas for temperature detection of plants planted in greenhouses)： So we packaged the temperature sensor in transparent plastic (with a button to ensure basic sealing), exposed it to sunlight for five minutes, observed the temperature changes, and opened the packaging after five minutes to return to room temperature. We compared it with the same day's room temperature to verify whether the temperature monitoring was basically accurate.
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Below is the final result image
Discussion and Reflection:
1. We found that temperature fluctuations are relatively large and not as stable as expected around a certain temperature value: Later on, we found out that it was because a smaller y-axis range was chosen for clearer image drawing, resulting in enlarged image changes. Another reason was that the sensor's connection line was too short, and during testing, it was inevitable to be closer to the electronic components. This also caused the temperature to rise and fall, perhaps due to the continuous heat dissipation of the electronic components. Approaching the sensor with hands or other objects significantly increases the temperature, confirming the authenticity of this possibility
2. The average temperature tested was slightly higher than the room temperature displayed on the indoor temperature monitor: this may be due to: ① The sensor is too close to other electronic components and has a high temperature. ② The sensor testing location is relatively close to the back row of the laboratory, and sunlight exposure is inevitable. However, after our observation of indoor temperature testing, the sensor should be located in the middle ceiling position of the laboratory, with a lower temperature.