NFC does not work: why the module on the Sony phone, iphone stopped working, the antenna does not work well

NFC card emulation mode

Card emulation mode puts the NFC device in passive communication mode. The device acts exactly like a smart card. The illustration shows some of the ways you can use an NFC device in card emulation mode. It’s important to remember that NFC security (via SE or HCE) only protects tokens used to identify an individual. You must have an application that ensures data security.

Using card emulation mode.

Your NFC-enabled device may emulate multiple smart cards, and smart card support may include more than one form of identification. For example, the same digital wallet can store loyalty cards and credit cards.

NFC Read/Write Mode

When operating in read/write mode, most NFC devices act as readers, as shown here. The NFC device is in active mode to read the contents of the tag. When it encounters two or more tags, it uses an anti-collision algorithm to select only one tag. The NFC device must also detect the tag type (ISO/IEC 14443 A/B or FeliCa) and interact with it accordingly. The method used to perform anticollision depends on the tag type.

Using read/write mode.

An application that interacts with NFC data interprets the tag data and reacts accordingly. For example, when reading a tag containing a Uniform Resource Identifier (URI), the device opens a browser, and the browser opens the content pointed to by the URI. All users see the browser with the web content displayed in it – the process of opening the URI remains hidden from view.

The tag creator can protect the content of the tag. Some tags provide a global lock, while other tags allow you to lock selected data in a protected area of ​​memory. When the tag remains unlocked, the NFC device can also write data to the tag. To write data to a tag, your device must have a tag writer application such as TagWriter. After launching the application, the following steps are usually used to write data to the tag:

1. Select the encoding type. The encoding type determines the type of data that the tag contains. Here are some typical encoding types:
   • Contact
   • URI
   • Plain text
   • Short Message Service (SMS)
   • Email
   • Phone
   • Bluetooth
2. Define a bookmark to hold data.
3. Create data.
4. Select encoding options, which may include:
   • Block tag from further changes
   • Writing multiple tags using the same data
   • Confirmation of overwriting existing tag data
5. Click a tag to encode it ,
   The process usually takes a few seconds, so you must leave the device in place until the application tells you that the encoding is complete.

NFC peer-to-peer mode

Two powered devices can participate in peer-to-peer mode, which is specific to NFC. However, the initiator is launched with its RF field on, and the target is launched with its RF field turned off. (The target can also go into sleep mode to reduce power consumption.) The state of the RF field changes with the direction of communication. This figure shows a typical usage for peer-to-peer mode.

Using peer-to-peer mode.

Be sure to note that NFC devices use the eavesdropping protocol before speaking. Devices listen to ensure no other device is transmitting before the device attempts to transmit any information. Using Listen Before Talk helps ensure that communication between devices is not affected by interference from other devices.

During the initial communication, the two devices determine the communication parameters such as the data block size. The maximum data block size is 256 bytes. In many cases, peer-to-peer mode is used to pair devices using some other means of transferring the actual data, such as Wi-Fi or Bluetooth. This process is called Connection handover.

What should I do if the NFC technology does not work?

First of all, the user should check the presence of NFC in his smartphone.

For this you need:

• enter the main menu;
• find the “Settings” section;
• enter the subsection “Wireless networks”;
• check if the NFC function is available.

There should be a checkmark next to this item in the phone menu. Thus, you can make sure that the nfs in the smartphone is and is active. Also, depending on the required task, you need to make sure that the nfs module is on the device with which you are pairing. Otherwise, file transfer cannot be performed.

If the NFC chip is built into the smartphone, but still does not work, you can perform one more algorithm in the settings:

• Go to “Settings”;
• Section “Wireless networks”;
• Manually switch the security element from built-in to HCE Wallet.

In order to correct this situation you need:

1. Go to the “Settings” section of the smartphone.
2. Find subsection “Battery”.
3. Click on “Power saver” (three dots on the top right).
4. Find the NFC service there and check the box next to “Do not save”.

This setting can be completely canceled if the need arises.

For the correct operation of all services and applications of the phone, its general technical condition is very important. It is necessary to check it for viruses and failures in a timely manner and fix problems.

However, if fixing the settings inside the phone did not help, installing an external nfs module will be the best solution.

Many of them are easy to find in the most ordinary electronics and technology stores. Their cost is usually within reason and affordable for a user of any income level. Each such module can be installed independently at home – this does not require any special skills or knowledge.

After installing an external nfs chip, it is important to check its performance as soon as possible to make sure that the function is now working properly.

Most common causes

If we consider the most common reasons why nfs suddenly stopped working on the phone, then they will be as follows:

• lack of a built-in nfs module for factory reasons;
• incorrect settings inside the device;
• lack of a chip, or incompatibility with the interface device;
• external nfs module damaged or incompatible with the smartphone.

Of course, if the phone was badly damaged (falling from a height, heavy pollution, staying in water for a long time), then many of its functions, including NFC, may not work. In order to accurately diagnose what exactly caused the module to malfunction, it is worth contacting a technical service center.

About what to do if the cause of the problem in the settings has already been written above. But what measures should be taken if the external NFC module does not work, or the internal antenna of the device is faulty?

NFC antenna failure

Of course, the simplest recommendation is to change your gadget or buy a new external module. But you don’t always want to change the entire device because of a small breakdown.

If it is not possible to turn to technicians, you can carry out simple procedures yourself:

1. Gently remove the device cover.
2. Check if the nfs antenna is present.
3. Without pressing hard, try tightening the ground screws (on the top of the device next to the battery).
4. If an external antenna unit is installed, check that it is installed correctly. One part of it should be under the battery, and the second, the “tail” on top, above the battery.

It is also worth remembering that the operation of the NFS antenna can be affected by the outer shell of the device (case, overlay, etc.). It is not recommended to use them when performing contactless transactions. The same applies to the chip itself – after purchase, the protective film from the antenna must be carefully removed, otherwise the nfc function may not work.

Be that as it may, malfunctions of this particular function of smartphones are not so common. Most often, the reason is simple and you can fix it yourself by performing a few simple steps in the settings.