iot Connecting with Other Devices

The iot module provides a collection of classes to connect to WiFi and exchange data with other devices, such as Raspberry Pis.

WiFi

This class can be used to connect the Wio Link board to WiFi.

class iot.WiFi(ssid, password)

Stores the WiFi ssid and password, so when the connect() method is called, the Wio Link board will connect to the specified WiFi ssid with the password.

Note

After WiFi is successfully connected, the Wio Link board will attempt to access the same WiFi at each subsequent boot. You can click the “Soft Reset” button to get the terminal to work again.

WiFi.connect()

When the connect() method is called, the Wio Link board will connect to the specified WiFi ssid with the password specified when object is created.

Example:

# Connects to a WiFi access point
# with SSID starbucks
# and Password 12345678

from iot import WiFi
wifi = WiFi(ssid="starbucks", password="12345678")
wifi.connect()

Node-RED

This class can be used to send data to any device that runs Node-RED, such as Raspberry Pis, or even a Node-RED instance running on the cloud, provided the IP address of the hosting machine is known.

class iot.NodeRed(ip[, port=1880])

Stores the ip address (or domain) of the machine running Node-RED. If Node-RED runs on a different port than 1880, the port parameter can be used to specify the port.

NodeRed.send_http(url, data, debug[=True])

Send the specified data to the http-in node in the Node-RED flow. the url parameter needs to be exactly the same as the URL field of the http-in node (shown below). data can either be a number, a string, or a dictionary. By default, if the data is sent successfully, the program will prompt "Data sent!. If that is undesirable, you can turn it off by setting debug to False.

Example:

# Connects to a WiFi access point
# with SSID starbucks
# and Password 12345678

from iot import WiFi, NodeRed
from sensors import TemperatureSensor
import time

wifi = WiFi(ssid="starbucks", password="12345678")
wifi.connect()

# Temperature Sensor is connected to Port 3
temp_sensor = TemperatureSensor(3)

# Node-RED is hosted on a machine with IP 192.168.1.123
# It has a http in node configured with URL /test

node = NodeRed(ip="192.168.1.123")

# Sends temperature and humidity data to Node-RED every 10 seconds

while True:
    t = temp_sensor.get_temperature()
    h = temp_sensor.get_humidity()

    data_dict = {
        "temperature": t,
        "humidity": h
    }

    node.send_http(url="/test", data=data_dict)
    time.sleep(10)

Connecting to BC Server

class iot.BcServer

There is a dedicated server set up at Boston College with a Node-RED instance running for data collection purposes. To use the server, you can directly use this class. No parameters is needed to set it up.

BcServer.send_http(data, debug[=True])

Specify the data, either a JSON or a String, and this method will send the data directly to the BC server. No need to specify IP or URL. By default, if the data is sent successfully, the program will prompt "Data sent!. If that is undesirable, you can turn it off by setting debug to False.