[PYTHON] [Don't refer to 04.02.17] Display the temperature sensor on a real-time graph with rasberry pi 3.

I'm sorry. I happened to browse this article related to massives I couldn't do it, so I will stop browsing once.

• Probably because the learning of face recognition was supported by the same raspberry pi, so the hierarchy was different. Also, if the cause etc. is found, it will be restarted. Thank you.

This time, I combined the temperature sensor of rasberry pi 3 and 20 kinds of sensors, Challenge real-time graphs with python.

I bought a raspberry pi 3 and 20 types of sensors

To get the wiring procedure and data procedure, go to the URL below.

• As you can see in this URL, the wiring is mixed in the order of GND etc. Anyway, there is no problem with the wiring as it was at this time ↓.

https://colo-ri.jp/develop/2016/05/raspberry-pi-ds18b20.html

• 04.02.17 Addendum Because wiring may be a little difficult to understand. First of all, about gpio

Next is the wiring method: Here, the DQ pin is connected to GPIO4, the VDD pin is connected to 3.3V, and the GND pin is connected to GND. Then, pull up between the DQ pin and the VDD pin with a 10KΩ resistor.

Later, personally, I wanted to make a real-time graph of the values, so I created the following code. When executed, it is as shown in the image below (* It is a little difficult to see, but the real-time graph is displayed in the upper left and the real-time sensor etc. is displayed in the lower left. Ignore the prompt for the capture shot in the upper right.)

＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝ ↓ Copy from here

#-*- coding: utf-8 -*-
#http://denshi.blog.jp/arduino/temperature-graph
import numpy as np
import matplotlib.pyplot as plt
import pygame
from pygame.locals import *
import serial
import sys
import os
import glob
from time import sleep

os.system('modprobe w1-gpio')
os.system('modprobe w1-gpio')

base_dir = '/sys/bus/w1/devices/'
device_folder = glob.glob(base_dir + '28*')[0]
device_file = device_folder + '/w1_slave'
def read_temp_raw():
f = open(device_file, 'r')
lines = f.readlines()
f.close()
return lines


def read_temp():
lines = read_temp_raw()
while lines[0].strip()[-3:] != 'YES':
sleep(0.2)
lines = read_temp_raw()
equals_pos = lines[1].find('t=')
if equals_pos != -1:
temp_string = lines[1][equals_pos + 2:]
temp_c = float(temp_string) / 1000.0
return temp_c
def main():

temps = [0]*100 #Temperature storage
t = np.arange(0,100,1)
plt.ion()
pygame.init() #Initialize Pygame
screen = pygame.display.set_mode((200, 200)) #Screen creation(100×100)
pygame.display.set_caption("Tilt angle") #Title bar
font = pygame.font.Font(None, 50) #Character setting

while True:
screen.fill((0,0,0)) #Clear screen
deviceTemp = read_temp()
print(read_temp())
temp = str(deviceTemp) # \Read up to n(\n is deleted)
text = font.render(temp + "[C]", False, (255,255,255)) #Setting of characters to be displayed
screen.blit(text, (10, 10)) #Render, display position
pygame.display.flip() #Refresh the screen to reflect the changes
#Updated list of temperature data
temps.pop(99)
temps.insert(0,float(temp))
#Graph display settings
line, = plt.plot(t, temps, 'r-',label="Temperature[C]") #Y-axis update
line.set_ydata(temps)
plt.title("Real-time temperature")
plt.xlabel("Time [s]")
plt.ylabel("Temperature [Celsius]")
plt.legend()
plt.grid()
plt.xlim([100,1])
plt.ylim([0,40])
plt.draw()
plt.clf()
#print(read_temp())
for event in pygame.event.get():
#End processing when the end button is pressed
if event.type == QUIT:
pygame.quit()
ser.close()
plt.close()
sys.exit()


if __name__ == '__main__':
main()