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POUsing member functions of class in global function before declaring object
 

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    <p>I have an event handler function and in that function there is a call to a member function of a class. The event handler function is declared in the class cpp file but not part of the class, it's no a member function. </p> <p>When i compile the code the compiler says that the function is note in the scope, because it's calling a member function within the global event handler function. </p> <p>My question is as followed: is there a way to use a meber function in a global function? (The object is created first on runtime).</p> <p>Below is the member function and global event handler:</p> <pre><code>Global event handler: void adbEventHandler(Connection * connection, adb_eventType event, uint16_t length, uint8_t * data) { Serial.println("In data recieve handler"); Serial.println("Data recieved: "); Serial.println(data[0]); Serial.println(data[1]); char a = data[0]; char b = data[1]; Serial.println(a); Serial.println(b); //uint16_t data2 = data; // Member function of USBCommunicator class SendBuffer(data, sizeof(data)); </code></pre> <p>}</p> <p>Member function:</p> <pre><code>void CommunicationModuleUSB::SendBuffer(uint8_t * Buffer, int Size){ connection-&gt;write(Size,(uint8_t*)&amp;Buffer); } </code></pre> <h1>Update</h1> <p>With the reply of Daniel (thank you!) i changed the member function in the header file and cpp file to static as followed:</p> <pre><code> static void CommunicationModuleUSB::SendBuffer(uint8_t* Buffer, int Size); </code></pre> <p>And the function is called in the global eventhandler as followed:</p> <pre><code>// Event handler for shell connection; called whenever data sent from Android to Microcontroller void adbEventHandler(Connection * connection, adb_eventType event, uint16_t length, uint8_t * data) { Serial.println("In data recieve handler"); Serial.println("Data recieved: "); //Serial.println(*data); Serial.println(data[0]); Serial.println(data[1]); char a = data[0]; char b = data[1]; Serial.println(a); Serial.println(b); //uint16_t data2 = data; CommunicationModuleUSB::SendBuffer(data, sizeof(data)); } </code></pre> <p>Only now i get the following error when i compile:</p> <p>C:\Users\Gebruiker\Documents\Arduino\libraries\CommunicationModuleUSB/CommunicationModuleUSB.h:26: error: extra qualification 'CommunicationModuleUSB::' on member 'SendBuffer.</p> <p>Does anybody have a idea who to solve that?</p> <h1>Update 2</h1> <p>Thanks again Daniel for your reply!</p> <p>I have changed the member function with your feedback. But now i get the following error:</p> <p>C:\Users\Gebruiker\Documents\Arduino\libraries\CommunicationModuleUSB\CommunicationModuleUSB.cpp:77: error: cannot declare member function 'static void CommunicationModuleUSB::SendBuffer(uint8_t*, int)' to have static linkage</p> <p>I have made the Connection variable static in the header file. Bellow is the header file and the function deffenition form the cpp file.</p> <p>Do you (or someone else) have any clue? All suggestions are welcome!</p> <p>Header file:</p> <pre><code>#include "CommunicationModule.h" #include &lt;SPI.h&gt; #include &lt;Adb.h&gt; class CommunicationModuleUSB : public CommunicationModule { public: CommunicationModuleUSB(); int Connect(); void Send(); int CheckConnection(); void Recieve(); static void SendBuffer(uint8_t* Buffer, int Size); void RecieveBuffer(char Buffer[], int Size); // Adb connection made this static....(is this right? static Connection * connection; // Elapsed time for sensor sampling long lastTime; private: }; </code></pre> <p>The function decleration in the cpp file:</p> <pre><code>static void CommunicationModuleUSB::SendBuffer(uint8_t* Buffer, int Size){ connection-&gt;write(Size,(uint8_t*)&amp;Buffer); } </code></pre> <p>And the call in the global function:</p> <pre><code>CommunicationModuleUSB::SendBuffer(data, sizeof(data)); </code></pre> <h1>Update 3</h1> <p>I have updated te code with the help of Daniel, the only problem that i have now is that the Connection variable that is declared in the class is not in the scope anymore.</p> <p>The compiler error that i get is as followed: C:\Users\Gebruiker\Documents\Arduino\libraries\CommunicationModuleUSB/CommunicationModuleUSB.cpp:79: undefined reference to <code>CommunicationModuleUSB::connection' C:\Users\Gebruiker\Documents\Arduino\libraries\CommunicationModuleUSB/CommunicationModuleUSB.cpp:79: undefined reference to</code>CommunicationModuleUSB::connection' CommunicationModuleUSB\CommunicationModuleUSB.cpp.o: In function <code>CommunicationModuleUSB::Connect()': C:\Users\Gebruiker\Documents\Arduino\libraries\CommunicationModuleUSB/CommunicationModuleUSB.cpp:53: undefined reference to</code>CommunicationModuleUSB::connection' C:\Users\Gebruiker\Documents\Arduino\libraries\CommunicationModuleUSB/CommunicationModuleUSB.cpp:53: undefined reference to `CommunicationModuleUSB::connection'</p> <p>The connection variable is declared in the header file as followed:</p> <pre><code>// Adb connection made this static....(is this right? static Connection * connection; </code></pre> <p>The variable is used in the following member functions:</p> <pre><code>void CommunicationModuleUSB::SendBuffer(uint8_t* Buffer, int Size){ connection-&gt;write(Size,(uint8_t*)&amp;Buffer); } </code></pre> <p>And is used in the following global event handler function:</p> <pre><code>// Event handler for shell connection; called whenever data sent from Android to Microcontroller void adbEventHandler(Connection * connection, adb_eventType event, uint16_t length, uint8_t * data) { Serial.println("In data recieve handler"); Serial.println("Data recieved: "); Serial.println(data[0]); Serial.println(data[1]); char a = data[0]; char b = data[1]; Serial.println(a); Serial.println(b); CommunicationModuleUSB::SendBuffer(data, sizeof(data)); } </code></pre> <p>Doe anybody have a suggestion how to solve this?</p>
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