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--- en:iot-open:practical:hardware:sut:esp32:iot_2 [2024/04/10 12:22] – [Task to be implemented] pczekalski
+++ en:iot-open:practical:hardware:sut:esp32:iot_2 [2024/04/21 11:39] (current) – pczekalski
@@ Line 1: / Line 1: @@
-<todo @pczekalski>Finish IOT2 scenario</todo>
 ====== IOT2: Reading IP address of the WiFi =====
 On the networking level, IP devices are identified by MAC. In the case of our laboratory and network, you will obtain the IP address from the DHCP server integrated with the WiFi access point. To connect to the WiFi network, one needs to use credentials that are present in the general laboratory description, available here:
@@ Line 22: / Line 21: @@
 ==== Task to be implemented ====
-Connect to the "internal IoT" WiFI access point. Present the obtained IP address on the selected display. Handle critical situations such as no access and present an appropriate message on the screen (e.g. error message). The steps below present only the reading part, not a display. Handling a display is presented in the EMBx scenarios, as listed above.
+Connect to the "internal IoT" WiFI access point. Present the obtained IP address on the selected display. Handle critical situations such as no access and present an appropriate message on the screen (e.g., an error message). The steps below present only the reading part, not a display. Handling a display is presented in the EMBx scenarios, as listed above.
 ==== Start ====
-Check if you can see a full LCD in your video stream. Book a device and create a dummy Arduino file with ''void setup()...'' and ''void loop()...''.
+Check if you can clearly see a full display (of your choice) in your video stream. Book a device and create a dummy Arduino file with ''void setup()...'' and ''void loop()...''.
@@ Line 35: / Line 34: @@
 #include <WiFi.h>
 </code>
-The WiFi library automatically initialises a singleton class ''WiFi'' that you can use to set up working mode, read MAC, and perform many other operations.
+The WiFi library automatically initialises a singleton class, ''WiFi,'' which you can use to set up working mode, read MAC and IP, and perform many other operations.
 === Step 2 ===
-Reading the MAC as a ''String'' is as easy as simply calling:
+Declare some constants, including AP SSID and passphrase and a variable to store IP:
 <code c>
-  WiFi.macAddress();
+const char* ssid = "REPLACE_WITH_CORRECT_SSID";
+const char* pass = "REPLACE_WITH_CORRENT_PASSPHRASE";
+IPAddress localIP;
 </code>
-==== Result validation ====
+Both ''ssid'' and ''pass'' are to be obtained from the hardware reference, available here: [[en:iot-open:practical:hardware:sut:esp32|]].
-Using another node should change the MAC read. Book another device and discover its MAC.
-===== FAQ =====
-**Can I change MAC?**: Actually, yes, you can. It is not advised, however, because you may accidentally generate an overlapping address that will collide with another device in the same network. You must first explicitly configure the ESP32 chip to work as an AP (Access Point, Server) or STA (WiFi Client) to do it. Sample stub code (for STA) may look as follows:
-<code c>
-#include <WiFi.h>
-#include <esp_wifi.h>
-uint8_t newMAC[] = {0xDE, 0xAD, 0xBE, 0xEF, 0xCA, 0xFE}; //Array of bytes with new MAC
+=== Step 3 ===
-void setup()
+Set your device in the STA mode and connect to the WiFi AP:
-{
+<code c>
   WiFi.mode(WIFI_STA);
-  esp_wifi_set_mac(WIFI_IF_STA, &newMAC[0]);
+  WiFi.begin(ssid, pass);
-}
+  while (WiFi.status() != WL_CONNECTED) {
+    //Drop some info on display about connecting
+    delay(1000);
+  }
 </code>
+The ''WiFi.begin(...)'' returns the following statuses (value, enumerator: meaning):
+  * 0, ''WL_IDLE_STATUS:'' temporary status assigned when WiFi.begin() is called
+  * 1, ''WL_NO_SSID_AVAIL:'' when no SSID are available
+  * 2, ''WL_SCAN_COMPLETED:'' scan networks is completed
+  * 3, ''WL_CONNECTED:'' when connected to a WiFi network
+  * 4, ''WL_CONNECT_FAILED:'' when the connection fails for all the attempts
+  * 5, ''WL_CONNECTION_LOST:'' when the connection is lost
+  * 6, ''WL_DISCONNECTED:'' when disconnected from a network
+=== Step 4 ===
+Reading the IP as a ''String'' is as easy as simply calling:
+<code c>
+   localIP = WiFi.localIP();
+</code>
+The ''IPAddress'' class contains the ''toString()'' method which formats the IP and returns in standard, dot-separated, four-octet text format.
+=== Step 5 ===
+Explicitly disconnect from the WiFi AP to free resources:
+<code c>
+  WiFi.disconnect();
+</code>
+Some useful WiFi functions are listed below:
+  * ''WiFi.reconnect()'' - reconnects the connection that was dropped, note it uses ''ssid'' and ''pass'' previously specified in the ''WiFi.begin(...)'', here you do not provide one.
+  * ''WiFi.RSSI()'' - once connected, you can get signal strength as ''int8_t'' integer.
+  * ''WiFi.setHostname(const char * hostname)'' - set host name for the ESP32 chip. Remember to use this function before connecting to the AP.
+==== Result validation ====
+You should be able to connect to the WiFi and present the dynamically assigned IP address by the DHCP server. <note>Note that due to the dynamic nature of the lab, IP addresses can change both during connection (on lease refresh) or between consecutive connects.</note>
+===== FAQ =====
+**I set a hostname, but it does appear on the router level.**: There are many possible reasons; one is an active registration in the router (AP) that keeps an old IP address, so you need to wait until it expires; another reason is you have changed the hostname when you were connected to the AP.\\
+**Can I use a manually configured IP?**: Actually, you can, but we strongly discourage it. You may accidentally overlap this IP address with some other device, router, or infrastructure, blocking its operation.
 <WRAP noprint>

en/iot-open/practical/hardware/sut/esp32/iot_2.1712751738.txt.gz · Last modified: 2024/04/10 12:22 by pczekalski