IoT Experiments: Temperature Sensing

Transcript

1. Advanced Computer Networks Tutorials, Spring 2021, CSIE NTUST 1 Iwan Setiawan <stwn at unsoed.ac.id> IoT Experiments: Temperature Sensing +Humidity
2. Advanced Computer Networks Tutorials, Spring 2021, CSIE NTUST 2 Iwan Setiawan <stwn at unsoed.ac.id> Previous Week’s Material • Electronics refresh – Components – Tools: Fritzing – Prototyping • LED switching experiments – Python and GPIO Zero – Mu editor • Traffic lights simulation Analog signal Compute Storage Digital signal Stallings, 2016 Communications
3. Advanced Computer Networks Tutorials, Spring 2021, CSIE NTUST 3 Iwan Setiawan <stwn at unsoed.ac.id> Objectives • Learn how to connect DHT11 sensor to the Raspberry Pi • Learn how to monitor temperature and humidity with the sensor through Python programs • Learn how to store data to a CSV file and display to a live graph Comma-separated values
4. Advanced Computer Networks Tutorials, Spring 2021, CSIE NTUST 4 Iwan Setiawan <stwn at unsoed.ac.id> Contents • Electronic circuit prototyping with DHT11 • Python programming using Adafruit DHT and matplotlib libraries • Setting up and running experiment set 2 – CPU temperature monitoring – Temperature and humidity monitoring with DHT11 – Data collecting, storing, and live-graphing
5. Advanced Computer Networks Tutorials, Spring 2021, CSIE NTUST 5 Iwan Setiawan <stwn at unsoed.ac.id> Prototyping using Fritzing • Download DHT11 part* • Import the part into Fritzing • Save and use the part for prototyping * https://github.com/jorgechacblogspot/librerias_fritzing Indicates that you need to take a picture of your work
6. Advanced Computer Networks Tutorials, Spring 2021, CSIE NTUST 6 Iwan Setiawan <stwn at unsoed.ac.id> Preparation • Raspberry Pi 4 set +Ethernet cable • Breadboard • Jumper wires • DHT11 sensor
7. Advanced Computer Networks Tutorials, Spring 2021, CSIE NTUST 7 Iwan Setiawan <stwn at unsoed.ac.id> Python Libraries • Adafruit DHT, a library for DHT11/DHT22 sensor – Install the library using pip3 $ sudo pip3 install Adafruit_DHT – Edit platform_detect.py file and add two lines in pi_version function $ sudo nano /usr/local/lib/python3.7/dist-packages/Adafruit_DHT/platform_detect.py … elif match.group(1) == ‘BCM2711’: return 3 ... • Matplotlib, a visualizations library, included in Raspberry Pi OS * https://github.com/adafruit/Adafruit_Python_DHT Notes: Add consistent <tab> when editing
8. Advanced Computer Networks Tutorials, Spring 2021, CSIE NTUST 8 Iwan Setiawan <stwn at unsoed.ac.id> CPU Temperature: Monitoring • Run Mu editor • Type the code, save, and run from gpiozero import CPUTemperature from time import sleep cpu = CPUTemperature() while True: temp = cpu.temperature print(temp) sleep(1) cpu_temp.py * https://gpiozero.readthedocs.io/en/stable/api_internal.html#cputemperature
9. Advanced Computer Networks Tutorials, Spring 2021, CSIE NTUST 9 Iwan Setiawan <stwn at unsoed.ac.id> CPU Temperature: Storing Data • Type the code, save, and run from gpiozero import CPUTemperature from time import sleep, strftime, time cpu = CPUTemperature() with open(“/home/pi/acnt/cpu_temp.csv”, ”a”) as log: while True: temp = cpu.temperature log.write(“{0},{1}\n”.format(strftime(“%Y-%m-%d %H:%M:%S”),str(temp))) sleep(1) cpu_temp-csv.py
10. Advanced Computer Networks Tutorials, Spring 2021, CSIE NTUST 10 Iwan Setiawan <stwn at unsoed.ac.id> CPU Temperature: Live-graphing • Type the code, save, and run • After the live graph is shown, execute a program, e.g. Chromium • Observe the graph from gpiozero import CPUTemperature from time import time import matplotlib.pyplot as plt cpu = CPUTemperature() plt.ion() # enable interactive mode x = [] # create dict x y = [] # create dict y while True: temp = cpu.temperature # get temp y.append(temp) # append temp to dict y x.append(time()) # append time to dict x plt.clf() # clear figure plt.scatter(x,y) # scatter plot for x and y plt.plot(x,y) # plot plt.pause(0.05) # pause plt.draw() # update figure cpu_temp-plot.py
11. Advanced Computer Networks Tutorials, Spring 2021, CSIE NTUST 11 Iwan Setiawan <stwn at unsoed.ac.id> Raspberry Pi Foundation, CC By-SA 4.0
12. Advanced Computer Networks Tutorials, Spring 2021, CSIE NTUST 12 Iwan Setiawan <stwn at unsoed.ac.id> DHT11 Prototyping +
13. Advanced Computer Networks Tutorials, Spring 2021, CSIE NTUST 13 Iwan Setiawan <stwn at unsoed.ac.id> Temp. and Humid. Monitoring • Type the code, save, and run import Adafruit_DHT sensor = Adafruit_DHT.DHT11 pin = 21 while True: try: humidity, temperature = Adafruit_DHT.read_retry(sensor, pin) if humidity is not None and temperature is not None: print(“Temperature: {0:0.1f}*C Humidity: {1:0.1f}%.format(temperature, humidity)) else: print(“Cannot pull data from the sensor”) except KeyboardInterrupt: exit() temp_humi.py
14. Advanced Computer Networks Tutorials, Spring 2021, CSIE NTUST 14 Iwan Setiawan <stwn at unsoed.ac.id> IoT Assignment 3 1. Find the basic principles of DHT11 – Temperature sensing – Humidity sensing 2. CPU temperature monitoring – Merge storing data and live-graphing codes to one code – Use Python functions – Add control flow: if the temperature is high, show an alert message
15. Advanced Computer Networks Tutorials, Spring 2021, CSIE NTUST 15 Iwan Setiawan <stwn at unsoed.ac.id> IoT Assignment 3 3. Simple smart home application: implementing two features – Storing and displaying the temperature data collected through DHT11 • Store the data to a CSV file • Display the data to a live graph – Indicators for temperature rising • Add a red LED and buzzer representing indicators • Control flow: If the temperature changes between 30 to 35 degree Celcius, the buzzer sounds long beep. If it is above 35 degree Celcius, the buzzer produces short beep plus the red LED turns on and a message shows up informing high temperature or heat alert. Simulate this situation with a demo • Question: Can we use DHT11 to detect fire? If yes, how would you use it to detect the event? If no, why?
16. Advanced Computer Networks Tutorials, Spring 2021, CSIE NTUST 16 Iwan Setiawan <stwn at unsoed.ac.id> Results to be Uploaded 1. Experiment results: photos and explanations 2. Assignment 3 results – Fritzing export image using Breadboard view – Photos and a demo video showing the results – Source code, screenshots/figures, and explanations Upload your experiment and assignment 3 results to Moodle • Using one PDF file • One group, one document • Upload your demo video somewhere, only attach the URL to the doc. 06/10 9pm code experiment
17. Advanced Computer Networks Tutorials, Spring 2021, CSIE NTUST 17 Iwan Setiawan <stwn at unsoed.ac.id> Resources • Raspberry Pi Foundation, “Temperature log,” 2021. [Online]. Available: https://projects.raspberrypi.org/en/- projects/temperature-log • Stack Overflow, “cannot import name 'Beaglebone_- Black_Driver' from 'Adafruit_DHT',” 2020. [Online]. Available: https://stackoverflow.com/questions/- 63232072/cannot-import-name-beaglebone-black- driver-from-adafruit-dht