ESP32
Temperature Web Server
Serve DHT22 / DHT11 sensor readings over Wi-Fi on a styled HTML page hosted by the ESP32.
Sensor
Web Server
WiFi
MicroPython
Temperature and Humidity Web Server¶
Reads temperature and humidity from a DHT22 (or DHT11) sensor connected to an ESP32 and serves the values over a simple HTTP web page using MicroPython.
Description¶
The project consists of a single main.py file that:
- Connects the ESP32 to your Wi-Fi network.
- Initialises the DHT11/DHT22 sensor.
- Opens a TCP socket on port 80.
- Waits for HTTP connections and responds with a styled HTML page showing current sensor readings.
Code¶
try:
import usocket as socket
except:
import socket
import network
from machine import Pin
import dht
import esp
esp.osdebug(None)
import gc
gc.collect()
# Configuration
ssid = 'REPLACE_WITH_YOUR_SSID'
password = 'REPLACE_WITH_YOUR_PASSWORD'
# Connect to Wi-Fi
station = network.WLAN(network.STA_IF)
station.active(False)
station.active(True)
station.disconnect()
station.connect(ssid, password)
import time
max_wait = 20
while max_wait > 0:
if station.isconnected():
break
max_wait -= 1
print('waiting for connection...')
time.sleep(1)
if station.isconnected():
print('Connection successful')
print(station.ifconfig())
else:
print('Connection failed')
import sys
sys.exit()
# Sensor setup
sensor = dht.DHT11(Pin(4))
#sensor = dht.DHT22(Pin(4))
def read_sensor():
global temp, hum
temp = hum = 0
try:
sensor.measure()
temp = sensor.temperature()
hum = sensor.humidity()
if (isinstance(temp, float) and isinstance(hum, float)) or (isinstance(temp, int) and isinstance(hum, int)):
msg = (b'{0:3.1f},{1:3.1f}'.format(temp, hum))
# uncomment for Fahrenheit
#temp = temp * (9/5) + 32.0
hum = round(hum, 2)
return(msg)
else:
return('Invalid sensor readings.')
except OSError as e:
return('Failed to read sensor.')
def web_page():
html = """<!DOCTYPE HTML><html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.7.2/css/all.css" integrity="sha384-fnmOCqbTlWIlj8LyTjo7mOUStjsKC4pOpQbqyi7RrhN7udi9RwhKkMHpvLbHG9Sr" crossorigin="anonymous">
<style>
html {
font-family: Arial;
display: inline-block;
margin: 0px auto;
text-align: center;
}
h2 { font-size: 3.0rem; }
p { font-size: 3.0rem; }
.units { font-size: 1.2rem; }
.dht-labels{
font-size: 1.5rem;
vertical-align:middle;
padding-bottom: 15px;
}
</style>
</head>
<body>
<h2>ESP DHT Server</h2>
<p>
<i class="fas fa-thermometer-half" style="color:#059e8a;"></i>
<span class="dht-labels">Temperature</span>
<span>"""+str(temp)+"""</span>
<sup class="units">°C</sup>
</p>
<p>
<i class="fas fa-tint" style="color:#00add6;"></i>
<span class="dht-labels">Humidity</span>
<span>"""+str(hum)+"""</span>
<sup class="units">%</sup>
</p>
</body>
</html>"""
return html
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
s.bind(('', 80))
s.listen(5)
while True:
try:
conn, addr = s.accept()
conn.settimeout(5)
print('Got a connection from %s' % str(addr))
request = conn.recv(1024)
print('Content = %s' % str(request))
sensor_readings = read_sensor()
print(sensor_readings)
response = web_page()
response_bytes = response.encode('utf-8')
conn.send(b'HTTP/1.1 200 OK\r\n')
conn.send(b'Content-Type: text/html\r\n')
conn.send(b'Content-Length: ' + str(len(response_bytes)).encode() + b'\r\n')
conn.send(b'Connection: close\r\n\r\n')
conn.sendall(response_bytes)
except Exception as e:
print('Error: %s' % str(e))
finally:
conn.close()
Wiring¶
DHT22 (or DHT11) to ESP32¶
Wiring Diagram¶
