# 3.35 WiFi Real-time Display
## 3.35.1 Overview
In this project, we display the values of temperature and humidity sensor, pressure sensor, photoresistor, sound sensor, PIR motion sensor and ultrasonic sensor on the web page.
## 3.35.2 Test Code
In Files, open **3-35-wifiWebpageDisplay.py** and click .
**Code:**
```python
'''
* Filename : 3-35-wifiWebpageDisplay
* Thonny : Thonny 4.1.4
* Auther : http//www.keyestudio.com
'''
import network
import socket
import time
import json
import machine
from machine import Pin, ADC, I2C,SoftI2C,PWM
import aht20
# WiFi connection information
# SSID = 'your WiFi name' # your WiFi name
# PASSWORD = 'your WiFi password' # your WiFi password
SSID = 'ChinaNet_2.4G' # your WiFi name
PASSWORD = 'ChinaNet@233' # your WiFi password
# initialize sensor
# photoresistor
light_sensor = ADC(Pin(36))
light_sensor.atten(ADC.ATTN_11DB)
# ultrasonic sensor
# define the control pins of ultrasonic sensor
Trig = Pin(5, Pin.OUT)
Echo = Pin(4, Pin.IN)
distance = 0 # set initial distance value to 0
soundVelocity = 340 #Set the speed of sound.
# PIR sensor
pir_sensor = Pin(19, Pin.IN)
# AHT20 sensor
i2c = SoftI2C(scl=Pin(22), sda=Pin(21))
aht20Sensor = aht20.AHT20(i2c)
def getDistance():
# maintain Trig pin at high for 10us to enable ultrasonic sensor
Trig.value(1)
time.sleep_us(10)
Trig.value(0)
#Start timing, the initial time of ultrasonic propagation in the air
while Echo.value() == 0:
Start = time.ticks_us()
#The time of receiving the reflected ultrasonic wave
while Echo.value() == 1:
Stop = time.ticks_us()
#The received time minus the initial time is the total time
Time = time.ticks_diff(Stop,Start)
#Calculate the distance according to the formula gives the result in meters.
#Divide by 1000 to convert to centimeters.
distance = Time * soundVelocity //2 // 10000
#return the calculated result
return distance
# connect to WiFi
def connect_wifi(ssid, password):
wlan = network.WLAN(network.STA_IF) # Create WLAN objects using STA mode (client mode)
wlan.active(True) # activate WLAN interface
wlan.connect(ssid, password) # Connect to the specified WiFi network
timeout = 10 # Connect timeout duration, in seconds
while not wlan.isconnected() and timeout > 0: # If the connection fails and the timeout period does not expire, check the connection status again
print("Connecting to WiFi...")
time.sleep(1)
timeout -= 1
if not wlan.isconnected(): # If the connection is not successful after timeout, an exception is thrown
raise Exception("Could not connect to WiFi")
print('Network config:', wlan.ifconfig()) # Output network configuration (IP address, subnet mask, gateway, and DNS)
print('Connected to WiFi, IP address:', wlan.ifconfig()[0]) # output the IP address of the successful connection
return wlan
# create HTML page
def web_page():
html = """
ESP32 Sensor Data
ESP32 Sensor Data
Light Sensor Value:
Distance: cm
PIR Sensor:
Temperature: C
Humidity: %
"""
return html # Return the HTML page that contains the sensor data
# Start the Web server
def start_server():
wlan = connect_wifi(SSID, PASSWORD) # Connect to WiFi
addr = socket.getaddrinfo('0.0.0.0', 80)[0][-1] # Obtain the local IP address and port 80
s = socket.socket() # Create a socket object
s.bind(addr) # Bind sockets to addresses and ports
s.listen(5) # Start listening for incoming connections. The maximum number of connections is 5
print('Listening on', addr) # Print the address and port on which the server is listening
while True:
cl, addr = s.accept() # Accept a client connection
print('Client connected from', addr) # Print the address of the client
request = cl.recv(1024) # Receive client requests, up to 1024 bytes
request = str(request) # Convert the request to a string
print('Content = %s' % request) # Print request content
if 'GET /sensor_data' in request:
light_value = light_sensor.read()
distance = getDistance()
pir_value = pir_sensor.value()
temperature, humidity = aht20Sensor.read_temperature_humidity()
sensor_data = {
'light': light_value,
'distance': distance,
'pir': pir_value,
'temperature': temperature,
'humidity': humidity
}
response = 'HTTP/1.1 200 OK\nContent-Type: application/json\n\n'
response += json.dumps(sensor_data)
cl.send(response)
else:
response = web_page()
cl.send('HTTP/1.1 200 OK\n')
cl.send('Content-Type: text/html\n')
cl.send('Connection: close\n\n')
cl.sendall(response)
cl.close()
# Run server
try:
start_server() # Try starting the Web server
except Exception as e:
print('Failed to start server:', e) # If the startup fails, an error message is displayed
machine.reset() # Restart the device to try to reconnect
```
**Result:**
Upload the code, and the Shell shows the IP address after connecting to wifi.
Connect your computer/mobile phone and ESP32 to the same wifi, and you can access the IP address to see the values through your device.
If you are using a mobile phone hotspot, you can directly access the IP via the phone.
