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• Implementing WiFi-Direct in Arduino library WiFi101

  Asad Zia • 05/17/2016 at 11:17 • 3 comments

  Atmel website says that the chip WINC1500 supports WiFi-Direct. The WiFi101 software library that comes with Arduino IDE has no API that indicate WiFi-Direct support. The first step is to add WiFi-Direct functionality into WiFi101 library.

  I forked the WiFi101 on github and soon discovered that the file WiFi.cpp is the best place to implement the additional APIs needed to connect to WiFi-Direct. I added the follwing APIs:

   /*
  
  * Start Wifi as P2P device. P2P is also known as Wi-Fi Direct.
  
  *
  
  * param name: Set your device name which will be shown in the peer device.
  
  * param channel: Wifi channel to use. Valid values are 0, 5 and 10.	*
  
  */
  
  uint8_t beginP2P(const char *name);
  
  
  uint8_t beginP2P(const char *name, uint8_t channel);

  This follows the same design pattern as the other APIs for configuring WiFi in station mode or Access Point mode.

  There is already an infrastructure in place to handle callbacks. I reused the same logic and implemented the WiFi-Direct API. I added a new example to demonstrate how to connect to WiFi-Direct, it is:

  #include <WiFi101.h>
  
  char name[] = "wifi101-p2p"; // P2P device name
  
  void setup() {
  
    // attempt to connect to Wifi-Direct:
    if ( WiFi.beginP2P(name) != WL_CONNECTED) {
      // don't continue:
      while (true);
    }
  
    // you're connected now, so print out the data:
    printCurrentNet();
    printWifiData();
  }
  
  void loop() {
    // communicate normally
  }
  

  
  

  When I coded everything and ran it, it did not connect. On investigation it turned out that I cannot use channel values between 1 to 12 as is the case for Access Point mode. The only allowed channel values are 0, 5 and 10. On using the correct channels it worked like a charm. Please see the connection dialog from Android below:

  You can find the updated library and working example at github https://github.com/asadziach/WiFi101

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