CODEWITHSUNDEEP
python-3.xtkinter
Yannis Xidianakis
Yannis Xidianakis

Reputation: 13

Change a label value dynamically in Tkinter

Fisrt of all i want to say that i am new in python I am trying to get the temperature value of a BME280 sensor and display it into a label widget via tkinter.

Here is my sample code:

import board
from tkinter import *
import busio
import adafruit_bme280

i2c = busio.I2C(board.SCL, board.SDA)
bme280 = adafruit_bme280.Adafruit_BME280_I2C(i2c)

main = Tk()
main.geometry('480x320')
main.configure(background = 'black')
main.title('Temperature Reading')

tempvar = StringVar()
tempvar.set("Temperature: " + str(bme280.temperature) + chr(32) + chr(176) + "C")
templbl = Label(main,
               relief = GROOVE,
               bd = 6,
               padx = 10,
               bg="blue",
               fg="yellow",
               font=('Mistral 14 bold'),
               textvariable = tempvar) 
templbl.pack()

main.mainloop()

The problem is that the data displayed in the label does not change. I think that my code does not retreive temperature data from the sensor. My will is to read the temperature data every 30 seconds and display them into label. How can i update the displayed data in the label when the sensor's data changed?

Thanks in advance for your help. Yannis

Upvotes: 1

Views: 196

Answers (1)

Eric Mathieu
Eric Mathieu

Reputation: 631

This is your code updated

import board
from tkinter import *
import busio
import adafruit_bme280

i2c = busio.I2C(board.SCL, board.SDA)
bme280 = adafruit_bme280.Adafruit_BME280_I2C(i2c)

main = Tk()
main.geometry('480x320')
main.configure(background = 'black')
main.title('Temperature Reading')

tempvar = StringVar()
templbl = Label(main,
               relief = GROOVE,
               bd = 6,
               padx = 10,
               bg="blue",
               fg="yellow",
               font=('Mistral 14 bold'),
               textvariable = tempvar)
templbl.pack()

def update_temp():
    bme280 = adafruit_bme280.Adafruit_BME280_I2C(i2c)
    tempvar.set("Temperature: " + str(bme280.temperature) + chr(32) + chr(176) + "C")
    main.after(30000, update_temp)

main.after(30000, update_temp)

main.mainloop()

Upvotes: 1

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