Orange Pi 5 sensors web app for monitoring temperature

readme.md

Orange Pi 5 sensors web app for monitoring temperature

how to run?

python orange_pi_sensors_web.py

how it works?

each 3 second ask json by command "sensors -j", split and write to temps.csv file.
when client make request, create image with line diagram from csv file.

orange_pi_sensors_web.py

import json
import time
import csv
import datetime

from flask import Flask, render_template, send_file

app = Flask(__name__)

data = {}

def save_temps_to_csv(data):
    with open('temps.csv', mode='a+') as csv_file:
        fieldnames = list(data.keys())
        writer = csv.DictWriter(csv_file, fieldnames=fieldnames)
        # if headers is empty, write them first
        csv_file.seek(0)
        first_char = csv_file.read(1)
        if not first_char:
            writer.writeheader()
        #write to file
        writer.writerow(data)

def get_temperatures():
    while True:
        cmd = "sensors -j"
        output = os.popen(cmd).read()
        try:
            temps = json.loads(output)
            data.clear()
            date_time = datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S')
            data['time']=date_time
            for key, value in temps.items():
                if 'temp1' in value and 'temp1_input' in value['temp1']:
                    data[key] = value['temp1']['temp1_input']
        except Exception as e:
            print(e)

        save_temps_to_csv(data)
        time.sleep(3)

@app.route('/')
def temp1_history_png():
    data = {
        'gpu_thermal-virtual-0': [],
        'littlecore_thermal-virtual-0': [],
        'bigcore0_thermal-virtual-0': [],
        'npu_thermal-virtual-0': [],
        'center_thermal-virtual-0': [],
        'bigcore1_thermal-virtual-0': [],
        'soc_thermal-virtual-0': []
    }

    with open('temps.csv') as csv_file:
        csv_reader = csv.DictReader(csv_file)
        for row in csv_reader:
            for key in data.keys():
                if key != 'time':
                  if key in row:
                      data[key].append(float(row[key]))

    return generate_chart(data)


def generate_chart(data):
    import matplotlib.pyplot as plt
    import io
    import base64

    plt.style.use('ggplot')

    plt.figure(figsize=(12, 6))
    for key, values in data.items():
        plt.plot(values, label=key)

    plt.legend()
    plt.title('Temperature history')
    plt.xlabel('Time (3 sec interval)')
    plt.ylabel('Temperature (Celsius)')

    img = io.BytesIO()
    plt.savefig(img)
    img.seek(0)
    
    chart_data = base64.b64encode(img.getvalue()).decode('utf-8')
    plt.close()

    return f'<img src="data:image/png;base64,{chart_data}">'


if __name__ == '__main__':
    import threading
    import os

    t = threading.Thread(target=get_temperatures)
    t.daemon = True
    t.start()

    app.run(host='0.0.0.0', port=5000)