Coap and IOT Systems

This article is based on Wikipedia and uses Google Translate...

the constrained Application Protocol (coap) is a software protocol designed to enable very simple electronic devices for interactive communication over the Internet. It is especially designed for small low-power sensors, switches, valve doors and components that require remote control or supervision over standard Internet networks. Coap is an application layer protocol used to connect devices in a network with limited resources, such as wireless sensor network nodes. Coap is designed to easily convert to simplified integration of HTTP and web, and can also meet special requirements, such as multicast support, very low overhead, and simplicity. Multicasting, low overhead, and simplicity are critical to the IOT and machine-to-machine (M2M) devices of the special network. This is often a heavy accumulation of memory and power, compared with traditional internet devices. Therefore, efficiency is very important. Coap can run on most analog devices that support udp or UDP.

To put it simply, coap simplifies the HTTP protocol and provides only four rest Methods: Put, get, post, and delete, unlike HTTP, coap simplifies the HTTP protocol. As for why it is rest, let's take a look at the articles on Iot system design on this page.

The advantage of using UDP for coap is that HTTP is not a feasible option for the network of IP addresses with limited resources. It occupies too many resources and too much bandwidth. For embedded devices such as IOT, this is a top priority.

1. coap uses a binary header instead of a text header)
2. coap reduces the number of available options for the header.
3. coap reduces some HTTP methods
4. coap supports detection devices

Take a look at this picture

Coap Database

I found several libraries that may be used in the future on the encyclopedia.

• Copper: a Firefox plug-in
• Node-coap nodejs coap Library
• Libcoap lightweight C implementation
• The txthings coap library is used for the twisted framework.

Arduino coap Library

Two libraries are found on GitHub.

The Network Driver Board must be used.

Others

The minimum Iot system coap version is in progress