Module COMX NB IoT

Example

Connect to the specified CoAP server with IP address 120.77.157.90 and port 5683 via NB-IoT module, then sequentially send a GET request, a POST request with post-test data, and a PUT request with put-test data, all using plain text format.

from m5stack import *
from m5ui import *
from uiflow import *
from comx.nbiot import NBIoT

setScreenColor(0x222222)

nb = NBIoT(tx=13, rx=5)
if nb.coap_connect('120.77.157.90', 5683):
  print(nb.coap_get('/m5stack-get'))
  print(nb.coap_post('/m5stack-post', 'post-test', content_format=0))
  print(nb.coap_put('/m5stack-put', 'put-test', content_format=0))

API

nb.get_gprs_network_registration()

• Checks the GPRS network registration status, returns whether the device has successfully registered to the GPRS network.

nb.get_network_registration()

• Checks the network registration status, returns whether the device has successfully registered to any network.

nb.get_single_quality()

• Checks the signal quality, returns the current network signal strength to assess the reliability of the connection.

nb.check_status()

• Checks the module status, returns the current operating status of the device to determine if it is working properly.

nb.coap_connect('', 5683)

• Connects to the specified IP address and port using the CoAP protocol. CoAP (Constrained Application Protocol) is a lightweight protocol commonly used for data transfer between IoT devices.

nb.coap_destroy()

• Disconnects from the CoAP server and destroys the CoAP session.

nb.coap_get('')

• Sends a GET request to the specified URL to retrieve data, with an option to use a secure connection.

nb.coap_post('', '', content_format=0)

• Sends a POST request to the specified URL with the data provided, specifying the content format (e.g., plain text), with an option to use a secure connection.

nb.coap_put('', '', content_format=0)

• Sends a PUT request to the specified URL to upload data, specifying the content format, with an option to use a secure connection.

NBIoT(tx=13, rx=5)

• Initializes the NB-IoT module by setting the TX and RX pin numbers used for serial communication.

nb.mqtt_check_connection()

• Checks the current MQTT connection status to confirm whether the device is successfully connected to the MQTT server.

nb.mqtt_connect('', 1883, '', '', '', 0)

• Connects to the specified MQTT server using the provided port, client ID, username, password, and keepalive interval. The common MQTT port is 1883.

nb.mqtt_disconnect()

• Disconnects from the current MQTT server.

nb.mqtt_poll()

• Polls for messages from the server, i.e., checks if the server has sent any new messages to the device.

nb.mqtt_publish('', '', 0)

• Publishes a message to the specified MQTT topic. The content of the message is specified by the payload, and QoS (Quality of Service) defines the reliability level of the message transmission.

nb.mqtt_subscribe('', nbiot_mqtt_cb, 0)

• Subscribes to the specified MQTT topic and sets the Quality of Service level for message transmission. The device will receive all messages on this topic.

def nbiot_mqtt_cb(nb_mq_topic, nb_mq_payload):
  global nb_topic, nb_msg, nb
  nb_topic = nb_mq_topic
  nb_msg = nb_mq_payload
  pass

• Sets a callback function when subscribing to a specific topic. nb_topic is the topic variable, and nb_msg is the message variable. The corresponding action will be executed when a message is received on the subscribed topic.

nb.mqtt_unsubscribe('')

• Unsubscribes from the specified MQTT topic, so the device will no longer receive messages on this topic.

nb.poweroff()

• Powers off the NB-IoT module, entering a low-power state.

nb.reset()

• Resets the NB-IoT module, causing it to restart and return to its initial state.

nb.set_command_echo_mode(0)

• Sets the command echo mode, which can be enabled or disabled. The echo mode determines whether the module returns the original command string after receiving a command.