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en:edu:zmitac:s2:iotn:lab3

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en:edu:zmitac:s2:iotn:lab3 [2022/03/18 22:56] – [Software] pczekalskien:edu:zmitac:s2:iotn:lab3 [2023/04/21 16:46] (current) – administrator
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 Network programming for the IoT Devices using CoAP protocol. Network programming for the IoT Devices using CoAP protocol.
  
-Following manual assumes you're familiar with [[en:edu:zmitac:s2:iotn:lab1|InT Networks: Laboratory 1 - Introduction]]. In case you're not, please get yourself familiar with it and spend some time practising. You can start your project stub using hints and guidance in the [[en:edu:zmitac:s2:iotn:lab1|InT Networks: Laboratory 1 - Introduction]] manual and modify it / extend as guided below.+The following manual assumes you're familiar with [[en:edu:zmitac:s2:iotn:lab1|InT Networks: Laboratory 1 - Introduction]]. If you're not, please familiarize yourself with it and spend some time practicing. Start your project stub using hints and guidance in the [[en:edu:zmitac:s2:iotn:lab1|InT Networks: Laboratory 1 - Introduction]] manual and modify it / extend as guided below.
  
-<note important>This manual is not intended to be stand-alone. You need to follow Laboratory 1 manual to prepare basics for the project then continue here.</note>+<note important>This manual is not intended to be stand-alone. You need to follow the Laboratory 1 manual to prepare the basics for the project, then continue here.</note>
  
-<note important>Computers in laboratory rooms 320, 321 and 336 use freezing software which means that for every startup, computers are restored to their initial state.</note>+<note important>Computers in laboratory rooms 320, 321, and 336 use freezing software, which means that for every startup, computers are restored to their initial state.</note>
  
 ==== Hardware ==== ==== Hardware ====
-We do not use any specific hardware here other than an LCD screen to present visual information. If you intend to extend your project and i.e. use a temperature and humidity sensor, refer to the [[en:edu:zmitac:s2:iotn:lab2|IoT Networks: Laboratory 2 - MQTT]] documentation on necessary libraries and configuration.+We do not use any specific hardware here besides an LCD screen to present visual information. If you intend to extend your project and i.e., use a temperature and humidity sensor, refer to the [[en:edu:zmitac:s2:iotn:lab2|IoT Networks: Laboratory 2 - MQTT]] documentation on necessary libraries and configuration.
  
  
 === Hardware-software components and libraries === === Hardware-software components and libraries ===
-Interfacing hardware requires the use of particular GPIOs. Laboratory nodes and hardware used needs specific configuration. Following chunks of code will help to set up proper hardware-software configuration.+Interfacing hardware requires the use of particular GPIOs. Laboratory nodes and hardware used need specific configurations. The following chunks of code will help to set up proper hardware-software configuration.
  
 == LCD display == == LCD display ==
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 </code> </code>
  
-To initialise it and instantiate controller object, use following GPIO definition and initialisation:+To initialize it and instantiate the controller object, use the following GPIO definition and initialization:
 <code c> <code c>
 const int rs = 12, en = 13, d4 = 4, d5 = 0, d6 = 2, d7 = 14; const int rs = 12, en = 13, d4 = 4, d5 = 0, d6 = 2, d7 = 14;
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 </code> </code>
  
-It is also necessary to tell the library about the display organisation as there is a variety of configurations possible. Here, the organisation is 2 lines, 16 columns each, so in the code, you need to explicitly initialise it:+It is also necessary to tell the library about the display organization, as various configurations are possible. Here, the organization is 2 lines, 16 columns each, so in the code, you need to explicitly initialize it:
 <code c> <code c>
 ... ...
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 ==== Software ==== ==== Software ====
-String formatting may be a challenge. An easy approach is to allocate a character buffer of the size of the LCD or just one display's line, or any other size, large enough to handle your text.+String formatting may be a challenge. An easy approach is to allocate a character buffer of the size of the LCD or just one display's line, or any other size large enough to handle your text.
 <code c> <code c>
 ... ...
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 </code> </code>
  
-To convert float into the string with formatting use ''sprintf'' function:+To convert float into the string with formatting, use ''sprintf'' function:
 <code c> <code c>
 ... ...
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 ... ...
 </code> </code>
-<note tip>''sprintf'' uses number of wildcards that are rendered with data. Refer to the c/c++ documentation on ''sprintf''. Here <code c>%2.1f</code> means: having float number render it to string using two digits before decimal point and one after. Temperature in our lab is always above 10C. <code c>%%</code> is an escape character to print a <code c>%</code> (percent) symbol.+<note tip>''sprintf'' uses a number of wildcards rendered with data. Refer to the c/c++ documentation on ''sprintf''. Here <code c>%2.1f</code> means: having a float number render it to string using two digits before the decimal point and one after. The temperature in our lab is always above 10C. <code c>%%</code> is an escape character to print a <code c>%</code> (percent) symbol.
 <code c> <code c>
 delay(time) delay(time)
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 === Software libraries === === Software libraries ===
-Software libraries are needed to handle communication between your IoT device and network and services. In this laboratory, you will connect your device to the WiFi access point (see the Networking section below for credentials) and use UDP (opposite to the Lab2 where you have used TCP). Your device will be automatically given an IP address that you may show on the LCD screen. Once WiFi is connected and works (PHY+MAC+NET layer protocols) then you can instantiate a CoAP client and ask the laboratory server or any other service present in your network (i.e. other device acting as CoAP server) for data or activity.\\+Software libraries are needed to communicate between your IoT device, network, and services. In this laboratory, you will connect your device to the WiFi access point (see the Networking section below for credentials) and use UDP (opposite Lab2, where you have used TCP). Your device will be automatically given an IP address that you may show on the LCD screen. Once WiFi is connected and works (PHY+MAC+NET layer protocols), then you can instantiate a CoAP client and ask the laboratory server or any other service present in your network (i.e., other device acting as CoAP server) for data or activity.\\
  
-The great feature of the CoAP is, you do not need to take care of the instant connection to the service on the application-level protocol. Just reconnecting WiFi, if the connection is dropped, is quite enough. UDP is a "connectionless" protocol and acts more-less as "send and forget", at least on the single message level. Obviously, ACK messages are expected but this approach is so much different to the MQTT on TCP, where connection break is instantly detected and yielded if only happens.+The outstanding feature of the CoAP is you do not need to take care of the instant connection to the service on the application-level protocol. Just reconnecting WiFi, if the connection is dropped, is quite enough. UDP is a "connectionless" protocol and acts more-less as "send and forget", at least on the single message level. Obviously, ACK messages are expected, but this approach is very different from the MQTT on TCP, where a connection break is instantly detected and yielded if it only happens.
  
 == WIFI and UDP == == WIFI and UDP ==
-A WiFi library is already included in the ESP8266 framework for the Arduino programming model, so there is no need to use library manager to add it. All is necessary is to include a header to your C code:+A WiFi library is already included in the ESP8266 framework for the Arduino programming model, so there is no need to use a library manager to add it. All that is necessary is to have a header included to your C code:
 <code c> <code c>
 ... ...
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 </code> </code>
  
-Then create some constant variables or declare token string identifiers (as below) with ''sSsid'' and ''sPassword'' (see Networking section for credentials) and instantiate WiFi communication object:+Then create some constant variables or declare token string identifiers (as below) with ''sSsid'' and ''sPassword'' (see Networking section for credentials) and instantiate the WiFi communication object:
 <code c> <code c>
 ... ...
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 ... ...
 </code> </code>
-The ''WiFi'' object is a singleton, static one. Try to connect to the AP, i.e. this way:+The ''WiFi'' object is a singleton, static one. Try to connect to the AP, i.e., this way:
 <code c> <code c>
 ... ...
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 Some useful code snippets are below.\\ Some useful code snippets are below.\\
-Checking if WiFi connection is successful:+Checking if the WiFi connection is successful:
 <code c> <code c>
 ... ...
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 ... ...
 </code> </code>
-Note, this object becomes automatically active and bound to the ''WiFi'' connection, when available. You do not need explicitly to initialise it or force connect it, however, you must initialise an object with an appropriate port. The default port for CoAP server is 5683 (UDP):+Note this object becomes automatically active and bound to the ''WiFi'' connection when available. You do not need explicitly to initialize it or force connect it. However, you must initialize an object with an appropriate port. The default port for the CoAP server is 5683 (UDP):
  
 <code c> <code c>
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 </code> </code>
  
-<note important>Please note, on the NET protocol level, in this scenario, you're connecting to the WiFi AP (STA), not setting your device to be a WiFi server (AP), so you need to set appropriate WiFi mode, as it may be previously used in AP, not STA mode.</note>+<note important>Please note, on the NET protocol level, in this scenario, you're connecting to the WiFi AP (STA), not setting your device to be a WiFi server (AP), so you need to set the appropriate WiFi mode, as it may be previously used in AP, not STA mode.</note>
  
-CoAP client or server both require to be instantiated using WiFi UDP connection (aforeinitialised ''Udp'' object), i.e. this way:+CoAP client or server both require to be instantiated using WiFi UDP connection (afore initialized ''Udp'' object), i.e., this way:
 <code c> <code c>
 ... ...
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 </code> </code>
  
-Because UDP is asynchronous due to its nature, each transaction (sending a request and waiting for the response) must be handled asynchronous way. For this purpose, we need to use callbacks.+Because UDP is asynchronous due to its nature, each transaction (sending a request and waiting for the response) must be handled asynchronously. For this purpose, we need to use callbacks.
 The sample callback function may have the following parameters: The sample callback function may have the following parameters:
 <code c> <code c>
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 </code> </code>
  
-As code runs asynchronously and many messages may come one by one, you should not process the ''packet'' itself but rather make a copy as quickly as possible, to release resources for handling another request (if any):+As code runs asynchronously and many messages may come one by one, you should not process the ''packet'' itself but instead make a copy as quickly as possible to release resources for handling another request (if any):
 <code c> <code c>
 ... ...
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 </code> </code>
  
-<note tip>You may have a variety of frames received but the common is to "ping" someone. If you detect ''packet.type==3 && packet.code==0'' then you were pinged. The following code snippet may help to identify ping and distinguish from the data packets:+<note tip>You may have a variety of frames received, but the common is to "ping" someone. If you detect ''packet.type==3 && packet.code==0'', then you were pinged. The following code snippet may help to identify ping and distinguish it from the data packets:
 <code c> <code c>
 ... ...
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 </note> </note>
  
-Once your callback function is ready it is time to send a request and wait for the callback function to be triggered when the response comes.+Once your callback function is ready, send a request and wait for the callback function to be triggered when the response comes.
 <note warning>Warning! You MUST configure and bind all response callback functions PRIOR to starting a CoAP communication, as below:</note> <note warning>Warning! You MUST configure and bind all response callback functions PRIOR to starting a CoAP communication, as below:</note>
 <code c> <code c>
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-Once the infrastructure is ready you can send a request and observe a response, i.e. in a ''void loop()'' function:+Once the infrastructure is ready, you can send a request and observe a response, i.e., in a ''void loop()'' function:
 <code c> <code c>
   int msgid = coap.get(ip,port,"");   int msgid = coap.get(ip,port,"");
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   - IP address of the server you want to connect to (''IPAddress'' object);   - IP address of the server you want to connect to (''IPAddress'' object);
   - port number (''int'');   - port number (''int'');
-  - URL, or actually its part coming AFTER the IP section of the URL. +  - URL, or actually, its part coming AFTER the IP section of the URL. 
-Regarding last parameter, ''""'' denotes root, so in fact the resulting request URI in this example is : ''%%coap://<IP>:<port>/<URL>%%''+Regarding the last parameter, ''""'' denotes root, so in fact, the resulting request URI in this example is: ''%%coap://<IP>:<port>/<URL>%%''
  
 ==== Networking ==== ==== Networking ====
-There is a WiFi 2.4GHz, IPv4 network available to the students. This is a PRIVATE network. This network is separated from the Internet but all connected devices to it can talk to another. There is a DHCP server with networking addressing scope 192.168.90.10-192.168.90.254. In this laboratory scenario, you work ONLY on the PRIVATE network.+There is a WiFi 2.4GHz, IPv4 network available to the students. This is a PRIVATE network. This network is separated from the Internet, but all connected devices can talk to one another. There is a DHCP server with networking addressing scope 192.168.90.10-192.168.90.254. In this laboratory scenario, you work ONLY on the PRIVATE network.
  
-<note warning>Do not use static IP! Some services present in the network have fixed IP addresses, overlapping it causes unavailability of your solution and this service, also to other teams! Use the only DHCP for obtaining a network address.</note>+<note warning>Do not use static IP! Some services in the network have fixed IP addresses; overlapping causes the unavailability of your solution and this service, also to other teams! Use only DHCP for obtaining a network address.</note>
  
 To connect to the wireless network, use the following credentials: To connect to the wireless network, use the following credentials:
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 There is a CoAP server awaiting you. There is a CoAP server awaiting you.
  
-You can also access it from the aforementioned PRIVATE network, using the following configuration and credentials:+You can also access it from the aforementioned PRIVATE network using the following configuration and credentials:
   * Address: 192.168.90.5   * Address: 192.168.90.5
   * Port: 5683, coaps is not implemented   * Port: 5683, coaps is not implemented
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 ==== Laboratory scenarios ==== ==== Laboratory scenarios ====
 You will implement two scenarios that you can bind into one code (or implement it as separate solutions) You will implement two scenarios that you can bind into one code (or implement it as separate solutions)
-<note tip>Mind keeping your code between meetings. It is regular that every next laboratory meeting you will extend your code by something extra.</note> 
-<pagebreak> 
  
 === Scenario 1 === === Scenario 1 ===
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 Connect to the CoAP server for the hello world URI and display returned text messages in the Serial console. Connect to the CoAP server for the hello world URI and display returned text messages in the Serial console.
  
-<pagebreak>+Report: 
 +  * Document your code and present an approach towards including CoAP communication protocol into the code.
  
 === Scenario 2 === === Scenario 2 ===
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 Report: Report:
-  * Present results including also a photo of the LCD with a message (code). +  * Present results, including a photo of the LCD with a message (code).
-<pagebreak>+
  
  
  
en/edu/zmitac/s2/iotn/lab3.1647640599.txt.gz · Last modified: by pczekalski