In this esp32 tutorial, we'll make an HTTP request to openweathermap. org in order to get weather conditions of a specific city with Zerynth.

Things used in this project

Hardware components

DFRobot FireBeetle Esp32

Software apps and online services
Zerynth Studio

Story

In this tutorial, we'll see how to make an HTTP request in order to get the weather condition of a specific city.

We’ll use Zerynth Studio to program the microcontroller-based board in Python.

Zerynth simplifies and speeds up IoT development allowing programming in Python or hybrid C/Python the most popular 32-bit microcontrollers and connecting them to the leading Cloud Infrastructures like AWS, Google Cloud, Microsoft Azure, IBM Watson, Ubidots, and many more.

Required Material

You need a board. You can select one of the 32-bit microcontroller devices supported by Zerynth. We’ve chosen the FireBeetle Esp32by DFRobot (read Zerynth documentation here).
You also need:
Zerynth Studio, a powerful IDE for embedded programming in Python that enables the IoT. You can download it here.

Assembling

No assembling required.

Programming

Once you have installed Zerynth Studio and created a Zerynth user, you have to register and virtualize the board.
Clone and uplink the Zerynth example "HTTP Weather" as shown in the video. Open the Serial Monitor to see the weather conditions of your city.
You can create your personal account at http://openweathermap.org/price to obtain your personal API key and enjoy discovering the weather conditions of the cities of the entire world.

Code

################################################################################
# Zerynth Weather
#
# Created by Zerynth Team 2015 CC
# Authors: G. Baldi, D. Mazzei
################################################################################



# import streams & socket
import streams
import socket

# import json parser, will be needed later
import json

# import the wifi interface
from wireless import wifi

# import the http module
import requests

# the wifi module needs a networking driver to be loaded
# in order to control the board hardware.
# THIS EXAMPLE IS SET TO WORK WITH ESP8266 WIFI DRIVER

# uncomment the following line to use the espressif esp8266 wifi driver (NodeMcu v2, Adafruit Feather Huzzah, Wemos d1 Mini, ...)
from espressif.esp8266wifi import esp8266wifi as wifi_driver

# uncomment the following line to use the BCM43362 driver (Particle Photon)
# from broadcom.bcm43362 import bcm43362 as wifi_driver

# uncomment the following line to use the ESP32 driver (Sparkfun Esp32 Thing, Olimex Esp32, ...)
# from espressif.esp32net import esp32wifi as wifi_driver

streams.serial()

# init the wifi driver!
# The driver automatically registers itself to the wifi interface
# with the correct configuration for the selected board
wifi_driver.auto_init()


# use the wifi interface to link to the Access Point
# change network name, security and password as needed
print("Establishing Link...")
try:
    # FOR THIS EXAMPLE TO WORK, "Network-Name" AND "Wifi-Password" MUST BE SET
    # TO MATCH YOUR ACTUAL NETWORK CONFIGURATION
    wifi.link("Network-Name",wifi.WIFI_WPA2,"Wifi-Password")
except Exception as e:
    print("ooops, something wrong while linking :(", e)
    while True:
        sleep(1000)

# let's try to connect to openweathermap.org to get some weather info
# for this example to work you need a openweathermap API key
# if you don't have one, you can get one for free here: http://openweathermap.org/price

# type here your API key!
# or you can use ours...however, if our calls quota is exceded 
# the example won't work :(
api_key = "bd4ba90e2b397e24a925e436a9d8fed9"
        
for i in range(3):
    try:
        print("Trying to connect...")
        # to get weather info you need to specify a correct api url
        # there are a lot of different urls with different functions
        # they are all documented here http://openweathermap.org/api
        
        # let's put the http query parameters in a dict
        params = {
            "APPID":api_key,
            "q":"Pisa"   # <----- here it goes your city
        }
        
        # the following url gets weather information in json based on the name of the city
        url="http://api.openweathermap.org/data/2.5/weather"
        # url resolution and http protocol handling are hidden inside the requests module
        response = requests.get(url,params=params)
        # if we get here, there has been no exception, exit the loop
        break
    except Exception as e:
        print(e)


try:
    # check status and print the result
    if response.status==200:
        print("Success!!")
        print("-------------")
        # it's time to parse the json response
        js = json.loads(response.content)
        # super easy!
        print("Weather:",js["weather"][0]["description"],js["main"]["temp"]-273,"degrees")
        print("-------------")
except Exception as e:
    print("ooops, something very wrong! :(",e)