strange error line 22

project/Core/Src/modbus-tcp.c

@@ -5,64 +5,29 @@
 
 char tcp_buffer[1024];
 
-struct Data_Modbus {//registers to hold the data of the modbus
-	uint16_t reg_00;//
-	uint16_t reg_01;//
-	uint16_t reg_03;//
-};
+#define MAX_REG 25
 
-struct Data_Modbus datamodbus;
-
-/*
-static err_t echo_recv( void *arg, struct tcp_pcb *pcb, struct pbuf *p, err_t err )
-{
-    int i;
-    int len;
-    char *pc;
-
-    if ( err == ERR_OK && p != NULL )
-    {
-        tcp_recved( pcb, p->tot_len );
-        pc = (char *)p->payload;
-        len =p->tot_len;
-
-        for( i=0; i<len; i++ )
-        {
-            tcp_buffer[i] = pc[i];
-        }
-
-        if( tcp_buffer[0] == 'X' )
-            echo_close( pcb );
-
-        pbuf_free( p );
-
-        if( len > tcp_sndbuf( pcb ) )
-            len= tcp_sndbuf( pcb );
-
-        tcp_write( pcb, tcp_buffer, len, 0 );
-        tcp_sent( pcb, NULL );
-    }
-    else
-    {
-        pbuf_free( p );
-    }
-
-    if( err == ERR_OK && p == NULL )
-    {
-        echo_close( pcb );
-    }
-
-    return ERR_OK;
-}
-*/
+uint16_t registers[MAX_REG];
 
 static err_t modbus_incomming_data(void *arg, struct tcp_pcb *pcb, struct pbuf *p, err_t err){
-	int i;
-	int len;
-	char *pc;
-	printf("data incomming\n");
+	u16_t len;
 
+	if (p != NULL){
+		printf("data not null\n");
+		//here im going to procces the modbusdata
+		len = p->tot_len;
 
+		//putting the bufer in the register array
+		for(int i=0; i<len; i++ ) {
+			registers[i] = p->payload[i];//getting the error "void value not ignored as it ought to be" on this line
+		}
+
+		if(registers[7] == 0x10){// Check if it's a Modbus Write Multiple Registers request (0x10)
+			printf("in writing multiple register mode\n");
+		}
+	} else if (err == ERR_OK){
+		tcp_close(pcb);//when everithing was ok close the tcpconnection
+	}
 	return ERR_OK;
 }