Detailed information about this class can be found in coap.
The following example sets up a Coap Server.
from network import WLAN
from network import Coap
# Callback to be called when a new resource has been added via PUT
def new_resource_callback(new_resource):
details = new_resource.get_details()
print("New resource has been created!")
print("URI: {}".format(details[0]))
print("Mediatype: {}".format(details[1]))
print("Max Age: {}".format(details[2]))
print("ETAG: {}".format(details[3]))
print("ETAG value: {}".format(details[4]))
print("Value: {}".format(new_resource.value()))
# Configure the properties of the new resource
# Mediatype, max_age and etag depends on the use-case, for this example set them randomly
new_resource.set_details(mediatype=Coap.MEDIATYPE_TEXT_PLAIN, max_age=100, etag=True)
# Connect to the network
wlan = WLAN(mode=WLAN.STA)
wlan.connect('your-ssid', auth=(WLAN.WPA2, 'your-key'))
# Initialize Coap module as CoAp Server, enable service discovery and new resources to be added via PUT
Coap.init(str(wlan.ifconfig()[0]), service_discovery=True, dynamic_resources=True)
# Register callback which will be called when new resource is added via PUT
Coap.register_new_resource_handler(new_resource_callback)
# Add an example resource with default value and plain text content format
r = Coap.add_resource("resource1", media_type=Coap.MEDIATYPE_TEXT_PLAIN, value="default_value")
# Add an attribute to the resource
r.add_attribute("title", "resource1")
# Add an attribute to the resource
r.add_attribute("ct", str(Coap.MEDIATYPE_TEXT_PLAIN))
# Configure the possible operations on the resource
r.callback(Coap.REQUEST_GET | Coap.REQUEST_POST | Coap.REQUEST_PUT, True)
# Add another example resource without default value, XML content format and E-Tag enabled
r = Coap.add_resource("resource2", media_type=Coap.MEDIATYPE_APP_XML, etag=True)
# Configure the possible operations on the resource
r.callback(Coap.REQUEST_GET | Coap.REQUEST_POST | Coap.REQUEST_PUT | Coap.REQUEST_DELETE, True)
This example shows how to use the CoAp Client session.
from network import WLAN
from network import Coap
import _thread
# Address of the CoAp Server which this Client Session wants to connect
COAP_SERVER_ADDRESS = "192.168.0.234"
# Port of the CoAp Server which this Client Session wants to connect
COAP_SERVER_PORT = 5683
# Callback handling the responses to the requests sent to a Coap Server
def response_callback(code, id_param, type_param, token, payload):
print("Code: {}".format(code))
# The ID can be used to pair the requests with the responses
print("ID: {}".format(id_param))
print("Type: {}".format(type_param))
print("Token: {}".format(token))
print("Payload: {}".format(payload))
# Connect to the network
wlan = WLAN(mode=WLAN.STA)
wlan.connect('your-ssid', auth=(WLAN.WPA2, 'your-key'))
# Initialize Coap module
Coap.init(str(wlan.ifconfig()[0]), service_discovery=True)
# Register the response handler for the requests the module initiates as a Coap Client
Coap.register_response_handler(response_callback)
# Create a new Client Session
session = Coap.new_client_session(COAP_SERVER_ADDRESS, COAP_SERVER_PORT)
# Send a GET Request to the CoAp Server asking for all resources via URI ".well-known/core"
id = session.send_request(Coap.REQUEST_GET, uri_path=".well-known/core", payload="payload", token="token1", include_options=True)
# The id can be used to match the request with the response in the response_callback
print(id)
# Send a GET Request to the CoAp Server asking for resource with URI "time"
id = session.send_request(Coap.REQUEST_GET, uri_path="time", payload="payload", token="token2", include_options=True)
print(id)
# Send a PUT request to the CoAp Server updating the resource with URI "time" to new value "ABCD"
id = session.send_request(Coap.REQUEST_PUT, uri_path="time",content_format=Coap.MEDIATYPE_TEXT_PLAIN, payload="ABCD", token="token3", include_options=True)
print(id)
This example snippet shows how to send messages to servers which accept CoAp messages without any options. In this case the URI should be placed in the “payload”.
# Token can be 8 bytes maximum
TOKEN = 12345678
# Payload must include the full URI (Host, Port, Path etc.)
FULL_URI_PATH = "abcd://server:1234/mypath.data"
# Disable normal CoAp options via include_options=False
id = session.send_request(Coap.REQUEST_GET, payload=FULL_URI_PATH, token=TOKEN, include_options=False)
