Suggestion for improvement: possibility to use custom methods for socket operations about microcoapy

[ftylitak]

@dmartauz I am very happy it worked as expected.

A proper example code for ESP32 was within our plans, so this change that you suggested is a good opportunity to proceed on doing.

My estimation is that within this week we will have a first version. We will keep you updated.

[ftylitak]

Hello @dmartauz

to my understanding you suggest to decouple the CoAP logic from the socket operations. Correct?

Indeed it is a good idea and future-proof. The initial version was implemented as is because on Pycom devices, the sockets are already encapsulated by the micropython API. So in case of WiFi, it is a typical UDP socket, whereas on NBIoT it is AT commands sent to the modem to handle the UDP socket on the modem.

Do you have any specific example of a user case where the network interface is not mapped to the internal IP stack? If yes, it would be a good input for us to use it as test scenario.

Eitherway, during next week we will proceed to the decoupling and we will keep you updated.

[dmartauz]

@ftylitak yes your understanding is correct.

My setup is ESP32 (WROVER module) with Quectel BC66 NB-IoT modem on a custom board. I already performed some testing of your lib against Thingsboard. First time without any modifications over WiFi connection, second time I passed content of "buffer" bytearray from sendPacket method to the NB-IoT modem via AT command. Worked as expected in both cases.

[ftylitak]

@dmartauz,

in branch IN-209-esp32-example there is a proposed solution to your suggestion through Pull Request #2 .

The branch also contains an example for ESP32 that show how to use a custom socket.

The custom dummy socket that has been used is:

microCoAPy/examples/esp32_wifi_coap_client_custom_socket.py

Lines 67 to 83 in a884270

	################################################################################
	## Custom socket implementation
	class CustomSocket:
	def __init__(self):
	print("CustomSocket: init")
	def sendto(self, bytes, address):
	print("CustomSocket: Sending bytes to: " + str(address))
	return len(bytes)
	def recvfrom(self, bufsize):
	print("CustomSocket: receiving max bytes: " + bufsize)
	return b"test data"
	def setblocking(self, flag):
	print(".", end="")
	################################################################################

and is set in microCoAPy instance as:

microCoAPy/examples/esp32_wifi_coap_client_custom_socket.py

Lines 91 to 95 in a884270

	# Initialize custom socket
	customSocket = CustomSocket()
	# Use custom socket to all operations of CoAP
	client.setCustomSocket(customSocket)

Could you give this branch a try?
Does this fullfil your requirements?

[ftylitak]

Closing the issue due to inactivity.

If there is any suggestion of a different approach on this subject, please open an new issue.