import tkinter as tk
import threading as th
import time
import RPi.GPIO as GPIO

# initialize GPIO
GPIO.setwarnings(False)
GPIO.setmode(GPIO.BCM)

RELAY = 21

# 初期状態：RELAY(PUMP) OFF
GPIO.setup(RELAY, GPIO.OUT, initial=GPIO.LOW)

root = tk.Tk()
tx = tk.StringVar()
tx.set('水補給時に押す。')
root.geometry('600x400')
root.title('給水装置')
label = tk.Label(root, textvariable = tx)
label.place(x=300, y=185)
    
def act():
    tx.set('５秒注水！')
    GPIO.output(RELAY, GPIO.HIGH)
    t = th.Timer(5, act2)
    t.start()
    
def act2():
    tx.set('水補給時に押す。')
    GPIO.output(RELAY, GPIO.LOW)

button = tk.Button(root, text = '注水ボタン', command = act)
button.place(x=200, y=180)

root.mainloop()