Published August 11, 2019 © CC BY-NC-SA

Web Weather Forecast Display on ESP8266 and MicroPython

Using a D1 mini to download and show one-week weather forecast data on an LCD 20x4 display.

BeginnerFull instructions provided7,651

Web Weather Forecast Display on ESP8266 and MicroPython

Things used in this project

Hardware components

Espressif Wemos D1 Mini

Alphanumeric LCD, 20 x 4

SparkFun Pushbutton switch 12mm

Breadboard (generic)

Jumper wires (generic)

Software apps and online services

MicroPython

Story

Sometime ago I've come across MetaWeather, a weather data service requires no authentication or registration. I figured I'll make a little weather forecast display. (But is the weather service accurate though? Maybe just ok in my country. You can always check more accurate weather forecast on your phone, right?)

I used a WeMos D1 mini ESP8266/ESP-12 board with a much larger LCD 2004A 20x4 display module (with a LCM1602 I2C board on it). The core principle is basically the same as my ESp8266 Web Clock project.

This device would:

Connect to WiFi on startup and make query.
Display and cycle 6-day weather forecast data on LCD every 1.5 seconds.
If you want an update of the weather data, press button to reset device or unplug/replug it.

EDIT: Originally I wanted this device to update automatically every 1 hour or whenever user pressed the button. It turns out the D1 would ran out of memory (get MemoryError in the JSON parsing stage) after first successful query! So now you need to reset device to manually update the data.

Wiring

LCD 20x4 I2C display:

Vcc -> 5V
Gnd -> G
SCL -> D1 (GPIO 5)
SDA -> D2 (GPIO 4)

Push button:

Leg 1 -> D3 (GPIO 0)
Leg 2 -> G

Since D3/GPIO 0 has a built-in pull up resistor, you don't need to add one here.

And sorry that I cannot provide a Fritzing diagram; my Fritzing stopped working after I upgrade my PC with a brand new graphic card in order to play Assassin's Creed: Odyssey at 40+ fps. (Totally worth it though.)

The D1 mini is mounted on a tiny breadboard and pasted behind the LCD.

Software

I use MicroPython for ESP8266 v1.11 firmware. I also use Thonny editor.

The LCD display needs a driver as well: https://github.com/dhylands/python_lcd

Download the.zip, unzip it and upload lcd_api.py and esp8266_i2c_lcd.py onto your board. This driver works on LCD 16x2 too and also on ESP32 boards.

from machine import I2C, Pin
from esp8266_i2c_lcd import I2cLcd
lcd = I2cLcd(I2C(scl=Pin(5), sda=Pin(4)), 0x27, 4, 20)
lcd.move_to(0, 0)
lcd.putstr("Test line 1\nTest line 2")

Just remember to use move_to(x, y) to set the proper start position for new text. "\n" switch the position to next line and itself counted as one character. If the writing position reached end of line it would also move to the next line. Texts also remains on the screen if they haven't been replaced by other texts.

To clear the whole screen:

lcd.move_to(0, 0)
lcd.putstr(" " * 80)

Which write 80 spaces to the display.

There are also some example can be found here.

WiFi

Change the value of the variables ssid and pw in the code to your WiFi AP name and password. Do not share these information online.

If the board lose WiFi connection after initial startup, check your WiFi and simply reset the board/reconnect power.

Power Supply

In my case, using a micro USB cable connecting the D1 and PC USB port is enough to power both the board and the LCD.

The MetaWeather API

In https://www.metaweather.com/api/ you can see detailed information of the API, which returns JSON data.

Long story short, you need to look up your city or location's woeid (Where On Earth ID):

https://www.metaweather.com/api/location/search/?query=taipei

which returns

[

{

"title":"Taipei",

"location_type":"City",

"woeid":2306179,

"latt_long":"25.085960, 121.561478"

}

]

Then you can request weather data for the specific location:

https://www.metaweather.com/api/location/2306179/

Which you'll get

{
"consolidated_weather":[
{
"id":5731243456987136,
"weather_state_name":"Light Rain",
"weather_state_abbr":"lr",
"wind_direction_compass":"WSW",
"created":"2019-08-11T04:42:02.309324Z",
"applicable_date":"2019-08-11",
"min_temp":28.765,
"max_temp":35.205,
"the_temp":35.535,
"wind_speed":7.43196686833161,
"wind_direction":253.49900702591995,
"air_pressure":998.385,
"humidity":59,
"visibility":10.609913107452478,
"predictability":75
},
{
"id":5498167426547712,
"weather_state_name":"Heavy Rain",
"weather_state_abbr":"hr",
"wind_direction_compass":"W",
"created":"2019-08-11T04:42:05.246764Z",
"applicable_date":"2019-08-12",
"min_temp":27.424999999999997,
"max_temp":33.925,
"the_temp":35.379999999999995,
"wind_speed":3.7761608663591297,
"wind_direction":259.33212604917344,
"air_pressure":1000.4449999999999,
"humidity":64,
"visibility":13.22681788356001,
"predictability":77
},
......
],
"time":"2019-08-11T13:44:16.507115+08:00",
"sun_rise":"2019-08-11T05:25:59.195781+08:00",
"sun_set":"2019-08-11T18:32:16.764758+08:00",
"timezone_name":"LMT",
"parent":{
"title":"Taiwan",
"location_type":"Country",
"woeid":23424971,
"latt_long":"23.598440, 121.017616"
},
"sources":[
{
"title":"BBC",
"slug":"bbc",
"url":"http://www.bbc.co.uk/weather/",
"crawl_rate":360
},
{
"title":"Forecast.io",
"slug":"forecast-io",
"url":"http://forecast.io/",
"crawl_rate":480
},
......
],
"title":"Taipei",
"location_type":"City",
"woeid":2306179,
"latt_long":"25.085960, 121.561478",
"timezone":"Asia/Taipei"
}

So we can parse the JSON data and extract what we want.

Serial Port/REPL Output

>>> %Run WebWeather.py

Connecting to WiFi...

connected.

Querying data...

successful.

Weather forecast for [Taipei]

Data time: [2019-08-11T13:00:32.397399+08:00]

Date: 08-11 [75%], Temp: 35/29 *C, Humid: 59, State: Light Rain

Date: 08-12 [77%], Temp: 34/27 *C, Humid: 64, State: Heavy Rain

Date: 08-13 [75%], Temp: 35/27 *C, Humid: 63, State: Light Rain

Date: 08-14 [71%], Temp: 35/27 *C, Humid: 61, State: Heavy Cloud

Date: 08-15 [75%], Temp: 35/27 *C, Humid: 56, State: Light Rain

Date: 08-16 [77%], Temp: 35/27 *C, Humid: 55, State: Heavy Rain

Code

Web Weather Forecast Display on ESP8266/D1 mini MicroPython Code

# Web Weather Forecast Display on ESP8266/D1 mini by Alan Wang
import network, urequests, utime, gc
import urequests
from machine import I2C, Pin, reset
from esp8266_i2c_lcd import I2cLcd # https://github.com/dhylands/python_lcd

gc.enable()


# user data
ssid = 'your_wifi_ssid'
pw   = 'your_wifi_password'
url  = 'https://www.metaweather.com/api/location/2306179/' # see https://www.metaweather.com/api/


# push button -> D3 and G
button = Pin(0, Pin.IN)


# LCD 2004 I2C: Vcc -> 5V, Gnd -> G, SCL -> D1,  SDA -> D2
lcd = I2cLcd(I2C(scl=Pin(5), sda=Pin(4)), 0x27, 4, 20)

# clear lcd
def lcd_clear():
    lcd.move_to(0, 0)
    lcd.putstr(' ' * 80)

# show text on lcd
def lcd_show(text, line):
    lcd.move_to(0, line)
    lcd.putstr(text)


# connecting to WiFi
wifi = network.WLAN(network.STA_IF)
wifi.active(True)
wifi.connect(ssid, pw)
lcd_clear()
lcd_show('Connecting to WiFi..', 0)
print('Connecting to WiFi...')
while not wifi.isconnected():
    pass
lcd_show('  connected.', 1)
print('  connected.')
print('')
utime.sleep(0.5)


# querying data
lcd_clear()
lcd_show('Querying data...', 0)
print('Querying data...')
date = []
w_state = []
min_temp = []
max_temp = []
humid = []
predic = []
loc = ''
time = ''
response = urequests.get(url)


if response.status_code == 200: # query successful
    lcd_show('  successful.', 1)
    print('  successful.')
    print('')
    utime.sleep(0.2)
    
    # parse JSON
    parsed = response.json()
    
    # excract data
    loc = (parsed['title'])[:18]
    time = parsed['time']
    print('Weather forecast for [' + loc + ']')
    print('Data time: [' + time + ']\n')

    for i in range(6):
        w_data = parsed['consolidated_weather'][i]
        date.append(w_data['applicable_date'][5:10])
        w_state.append(w_data['weather_state_name'])
        min_temp.append(round(float(w_data['min_temp'])))
        max_temp.append(round(float(w_data['max_temp'])))
        humid.append(int(w_data['humidity']))
        predic.append(int(w_data['predictability']))
        output_str = 'Date: {0} [{1}%], Temp: {2}/{3} *C, Humid: {4}, State: {5}'
        print(output_str.format(date[i], predic[i], max_temp[i], min_temp[i], humid[i], w_state[i]))

else: # query failed, roboot
    lcd_show('  failed.\n  Rebooting...', 1)
    print('  failed. Rebooting...')
    utime.sleep(0.5)
    machine.reset()


print('')
print('Press button or unplug/replug device to update weather data.')
lcd_clear()
index = 0


# display data on LCD
while True:
    
    if button.value() is 0:
        break

    if len(date) > 0:
        lcd_show('{:^20}'.format('[' + loc + ']'), 0)
        if index is 0:
            date_str = 'Today'
        else:
            date_str = 'Day {0}'.format(index + 1)
        lcd_show('{0}: {1} ({2}%)'.format(date_str, date[index], predic[index]), 1)
        lcd_show('{:^20}'.format('T: {0}/{1} *C, H: {2}% '.format(max_temp[index], min_temp[index], humid[index])), 2)
        lcd_show('{:^20}'.format(w_state[index]), 3)
        
        if index is 5:
            index = 0
        else:
            index += 1

    utime.sleep(1.5)


# user reboot
lcd_clear()
while button.value() is 0:
    pass
lcd_show('Rebooting...', 0)
print('Rebooting...\n')

utime.sleep(0.5)
reset()

Credits

Alan Wang

32 projects • 102 followers

Please do not ask me for free help for school or company projects. My time is not open sourced and you cannot buy it with free compliments.

Web Weather Forecast Display on ESP8266 and MicroPython

Things used in this project

Hardware components

Software apps and online services

Story

Wiring

Software

Power Supply

The MetaWeather API

Serial Port/REPL Output

Schematics

Web Weather Forecast Display on ESP8266/D1 mini Circuit Diagram

Code

Web Weather Forecast Display on ESP8266/D1 mini MicroPython Code

Credits

Alan Wang

Comments

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Web Weather Forecast Display on ESP8266 and MicroPython

Web Weather Forecast Display on ESP8266 and MicroPython

Things used in this project

Hardware components

Software apps and online services

Story

Wiring

Software

Power Supply

The MetaWeather API

Serial Port/REPL Output

Schematics

Web Weather Forecast Display on ESP8266/D1 mini Circuit Diagram

Code

Web Weather Forecast Display on ESP8266/D1 mini MicroPython Code

Credits

Alan Wang

Comments

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