SDK Usage

Introduction

The IoT Device SDK Tiny is lightweight interconnection middleware deployed on devices that have wide area network (WAN) capabilities and limited power consumption, storage, and compute resources. After the IoT Device SDK Tiny is deployed on such devices, you only need to call APIs to enable the devices to connect to the IoT platform, report data, and receive commands.
The IoT Device SDK Tiny provides device-cloud synergy capabilities by integrating various IoT interconnection protocol stacks, including MQTT, LwM2M, CoAP, Mbed TLS, and lwIP. With open APIs offered by the SDK, you can focus on your applications without getting into the specifics of protocol implementation. By leveraging these APIs, you can securely and efficiently connect to the Huawei Cloud IoT platform, speeding up development and deployment, while focusing on service promotion.
In addition, the SDK can be tailored. During the porting, components can be customized to save memory space and reduce the porting difficulty.

The IoT Device SDK Tiny can run on devices that do not run Linux OS, and can also be integrated into modules. However, it does not provide gateway services.

Directory Structure

**Table 1**
Level-1 Directory	Level-2 Directory	Level-3 Directory	Description
LiteOS_Lab	at	-	AT command framework
	cJSON	-	cJSON
	crc	-	Cyclic redundancy check (CRC)
	demos	-	Example
	driver	-	Driver framework
	docs	-	Documents such as user guides and API references
	fs	-	File system, including VFS, SPIffs, RAMfs, KIfs, DEVfs, and FATfs
	inc	-	Header files used internally in the kernel
	link_log	-	Logs
	link_misc	-	Miscellaneous files
	link_ota	-	OTA upgrade code implementation
	network	coap	CoAP adaptation and protocol implementation
		dtls	Mbed TLS adaptation and protocol implementation
		lwm2m	Adaptation of the open-source protocol stack wakaama of LwM2M
		mqtt	MQTT adaptation and protocol implementation
		tcpip	TCP/IP adaptation and protocol stack implementation, lwIP driver, OS adaptation and protocol stack implementation, and macOS_socket adaptation and protocol stack implementation
	oc	oc_coap	CoAP protocol adaptation to Huawei Cloud IoT platform
		oc_lwm2m	LwM2M protocol adaptation to Huawei Cloud IoT platform
		oc_mqtt	MQTT protocol adaptation to Huawei Cloud IoT platform
	os	osal	OS adaptation of IoT Device SDK Tiny
	os	xxos	Adaptation to OSs such as FreeRTOS, Linux, LiteOS, macOS, Nova OS, and μC/OS-II
	queue	-	Queue component code implementation
	secure_c	-	Security function library of C
	shell	-	Shell component code implementation
	stimer	-	Stimer component code implementation
	storage	-	Storage zone
	usip	-	USIP
	iot.mk	-	Makefile
	iot_config.h	-	Macro definition
	iot_link_config.h	-	-
	link_main.c	-	SDK initialization entry
	README.md	-	SDK introduction