Update docs (#6)

* Update README.md

.github/workflows/ci.yml

@@ -1,4 +1,4 @@
-name: 1nce-iot-c-sdk-workflows
+name: SDK-Checks
 
 on:
   push:

README.md

@@ -1,3 +1,5 @@
+[![SDK-Checks](https://github.com/1NCE-GmbH/1nce-iot-c-sdk/actions/workflows/ci.yml/badge.svg)](https://github.com/1NCE-GmbH/1nce-iot-c-sdk/actions/workflows/ci.yml)
+
 # 1NCE IoT C SDK
 
 ## Overview
@@ -10,24 +12,39 @@ The 1NCE IoT C-SDK is licensed under the [MIT](./LICENSE) open source license.
 1NCE IoT C SDK allows customers a seamless setup and use of all features as part of 1NCE Connectivity Suite. 
 1NCE IoT C SDK contains the following services: 
 
-![Alt text](./docs/doxygen/images/overview.png?raw=true "overview")
+<p align="center"><img src="./docs/doxygen/images/overview.png"><br>
+</p>
+
 ### MQTT Onboarding
 The connection to AWS IoT core is mainly done through MQTT, and Devices are created as "Things" that can have various attributes to define their functionality. After creating a representation of the “thing” in AWS IoT Core, a certificate, private key, and public key are generated for the device to enable secure communication to the cloud. In addition, policy configuration is needed to determine what are the permissions granted for the device. In the MQTT context, this can for example determine the topics that the device can Publish and/or Subscribe to.
-![Alt text](./docs/doxygen/images/mqtt_onboarding.png?raw=true "MQTT Onboarding")
-### CoaP Onboarding
+
+<p align="center"><img src="./docs/doxygen/images/mqtt_onboarding.png" width="70%"><br>
+</p>
+
+### CoAP Onboarding
 The 1NCE IoT c SDK also provides onboarding credentials for IoT devices communicating through DTLS. In this case, the device receives a DTLS Identity and a Pre-Shared Key (PSK) that can be used to establish a secure connection to the CoAP endpoint of 1NCE Data Broker.
-![Alt text](./docs/doxygen/images/coap_onboarding.png?raw=true "CoAP Onboarding")
+
+<p align="center"><img src="./docs/doxygen/images/coap_onboarding.png" width="70%"><br>
+</p>
+
+More details about device onboarding are available at [1NCE Developer Hub (SIM-as-an-Identity)](https://help.1nce.com/dev-hub/docs/connectivity-suite-sim-identity). 
+
 ### Translation Service (Binary conversion language)
-The translation service aims to minimize the payload size sent from the device to a simple byte array that can be converted to JSON Format. The resulting message is then sent using MQTT via the Data broker. Translating the byte array is done using Binary Conversion language which splits the array into a sequence of values defined in a translation template.
-![Alt text](./docs/doxygen/images/translation_service.png?raw=true "translation service")
+The translation service aims to minimize the payload size sent from the device to a simple byte array that can be converted to JSON Format. The resulting message is then sent using MQTT via the Data broker. Translating the byte array is done using Binary Conversion language which splits the array into a sequence of values defined in a translation template. 
+
+<p align="center"><img src="./docs/doxygen/images/translation_service.png"><br>
+</p>
+
+ Check  [1NCE Developer Hub (Translation service)](https://help.1nce.com/dev-hub/docs/connectivity-suite-translation-service) for further explantion of the translation template creation.
+
 ## Versioning
 1NCE IoT C SDK releases will follow a [Semantic versioning](https://en.wikipedia.org/wiki/Software_versioning#Semantic_versioning)
 Given a version number MAJOR.MINOR.PATCH, increment the:
 * MAJOR version when you make incompatible SDK changes,
 * MINOR version when you add functionality in a backward-compatible manner,
 * PATCH version when you make backward-compatible bug fixes.
 
-## Getting start 
+## Getting started 
 
 **This section shows you:**
 
@@ -49,16 +66,14 @@ The Examples used FreeRTOS as First Version.
 
 ### Prerequisite Tasks
 
-To set up and run the SDK you must first complete these tasks:
-
-- Install gcc to compile the project. For more information, see the https://gcc.gnu.org/install/index.html. you can find the downloads of the compiler.
+The SDK requires using a 1NCE SIM card with a connected AWS account configured through [1NCE Portal](https://portal.1nce.com/). GCC must also be installed to compile the project. For more information, see the https://gcc.gnu.org/install/index.html. you can find the downloads of the compiler.
 
 #### Contents
-* [Step1: Clone Repository](#Step1_Clone_Repository)
-* [Step2: Implement abstract functions](#Step2_Implement_abstract_functions)
-* [Step3: Integrate SDK in your Application](#Step3_Integrate_SDK_in_your_Application)
-* [Step4: Run your Application](#Step4_Run_your_Application)
-## Step1: Clone Repository 
+* [Step 1: Clone Repository](#Step1_Clone_Repository)
+* [Step 2: Implement abstract functions](#Step2_Implement_abstract_functions)
+* [Step 3: Integrate SDK in your Application](#Step3_Integrate_SDK_in_your_Application)
+* [Step 4: Run your Application](#Step4_Run_your_Application)
+### Step 1: Clone Repository 
 you clone the SDK for Embedded C in your project using git clone
 To clone using HTTPS
 ```
@@ -72,7 +87,7 @@ If you have downloaded the repo without using the ```--recurse-submodules``` arg
 ```
 git submodule update --init --recursive
 ```
-### Step2: Implement abstract functions
+### Step 2: Implement abstract functions
 You need to implement your four TLS functions how you want to access our endpoint onload or offload and also depending on your modem. 
 
 * nce_TLS_Connect
@@ -82,7 +97,7 @@ You need to implement your four TLS functions how you want to access our endpoin
 
 To implement your functions, we recommand to follow the examples.
 #### Examples Quectel BG96
-###### 1. Offload Certificate: 
+#### 1. Offload Certificate: 
 for the Implementation we use the psuedo code: 
 ```
 TlsTransportStatus_t TLS_Connect_impl(NetworkContext_t *pNetworkContext,
@@ -91,9 +106,9 @@ TlsTransportStatus_t TLS_Connect_impl(NetworkContext_t *pNetworkContext,
 			                          uint32_t receiveTimeoutMs, 
 			                          uint32_t sendTimeoutMs)
 ```
-1- [configure the onboarding socket](https://github.com/1NCE-GmbH/blueprint-freertos/blob/94b2f0a364c958df57fe75e969aeef674fece6ba/libraries/3rdparty/NCE_SDK/nce_bg96_configuration.c#L41)
-2- Create TCP Socket.
-3- Connect the socket with the endpoint ```ONBOARDING_ENDPOINT``` in port ```ONBOARDING_PORT```
+1. [configure the onboarding socket](https://github.com/1NCE-GmbH/blueprint-freertos/blob/94b2f0a364c958df57fe75e969aeef674fece6ba/libraries/3rdparty/NCE_SDK/nce_bg96_configuration.c#L41)
+2. Create TCP Socket.
+3. Connect the socket with the endpoint ```ONBOARDING_ENDPOINT``` in port ```ONBOARDING_PORT```
 ```
 int32_t TLS_send_impl(NetworkContext_t *pNetworkContext,
 			          const void *pBuffer,
@@ -109,30 +124,78 @@ Create Recv function via TLS for Quectel BG96 we can call At command ```AT+QSSLR
 ```
 void TLS_Disconnect_impl(NetworkContext_t *pNetworkContext)
 ```
-1- Call socket shutdown function to close the connection
-2- Free mbedTLS contexts.
-###### 2. Onload Certificate:
-For the Unload Certificate, we can refer to [using_mbedtls in FreeRTOS Demo](https://github.com/FreeRTOS/Lab-Project-FreeRTOS-Cellular-Demo/blob/main/source/coreMQTT/using_mbedtls.c)
-### Step3: Integrate SDK in your Application
-1NCE SDK is simple to integrate into every Embedded App written with C, To begin, you need to define an object type tls_api and the affect to their variable the networkContext and implemented functions as shown in the example below. 
+1. Call socket shutdown function to close the connection
+2. Free mbedTLS contexts.
+#### 2. Onload Certificate:
+For the Onload Certificate, we can refer to [using_mbedtls in FreeRTOS Demo](https://github.com/FreeRTOS/Lab-Project-FreeRTOS-Cellular-Demo/blob/main/source/coreMQTT/using_mbedtls.c)
+### Step 3: Integrate SDK in your Application
+
+1NCE SDK is simple to integrate into every Embedded App written with C. To begin, you need to define an object type tls_api and the affect to their variable the networkContext and implemented functions as shown in the example below. 
 ```
     tls_api xtls_api;
     xtls_api.pNetworkContext= &xNetworkContext;
     xtls_api.conn=TLS_Connect_impl;
     xtls_api.disconn=TLS_Disconnect_impl;
     xtls_api.tlssend=TLS_send_impl;
     xtls_api.tlsrecv=TLS_recv_impl;
-    nce_sdk(&xtls_api,1);
+```
+#### 1. MQTT
+The  object can then be passed to ```nce_sdk``` function as follows: 
+
+``` 
+   nce_sdk(&xtls_api,1);
 ```
 then you have the Root certificate stored in ```rootCA``` , Client certificate in ```clientCert``` , device private Key in ```prvKey```
 Thingname, endpoint and topic name also stored in ```nceThingName ```,```nceEndpoint```,```nceExampleTopic``` respectively.
-nce_sdk function had two functionality the first one is to plug and play with MQTT and also with CoAP protocol to use DTLS you need just to change the 1 to 0 
+
+#### 2. CoAP
+With CoAP protocol  (using DTLS) you need just to change the 1 to 0 
 ```
     nce_sdk(&xtls_api,0);
 ```
 then we can have the pre-shared key and identity stored in ```psk``` and ```pskIdentity```
 
-### Step4: Run your Application
+#### 3. Translation service
+
+```nce_generate_BCL_payload``` function can be used to convert payloads to binary format. The following figure shows a sample translation template that can be used to share GPS data and device information: 
+
+<p align="center"><img src="./docs/doxygen/images/translation_template_1.png"><br>
+</p>
+
+Considering case 1:
+
+<p align="center"><img src="./docs/doxygen/images/translation_template_2.png"><br>
+</p>
+
+The binary payload for this case can be generated as follows
+
+```
+    /* values to be sent */
+	uint8_t battery_level = 99;
+	uint8_t signal_strength = 84;
+	char software_version[] = "2.2.1";
+	
+    /* Template information */
+	char type[] = "UUS"; 
+	int bytelength[]={1,1,5};
+
+
+    uint8_t selector = 1  /* select case 1 */;
+	int location=1;
+	uint8_t packet[8];
+
+    /* Add battery level */
+	location = nce_generate_BCL_payload( type, 0,packet, selector,&battery_level,location,bytelength );
+    
+    /* Add signal strength */
+	location = nce_generate_BCL_payload( type, 1,packet, selector,&signal_strength,location,bytelength );
+    
+    /* Add software version */
+	location = nce_generate_BCL_payload( type, 2,packet, selector,software_version,location,bytelength );
+```
+The resulting packet can then be sent to the translation service for further processing
+
+### Step 4: Run your Application
 Run your code in ISO C99 
 
 ## Generating documentation