Sending or receiving content over NFC
In Cascades, you can use an NFC Share Card, or use the NFC Share API to send or receive content over NFC. Alternatively, you can use the C API library (libnfc and libnfc_bps) to send and receive content.
Some important items to consider when sharing various types of content:
- You can share any type of content over NFC. However, the size of the content you share should not exceed 1K. At a transfer speed of no more than 424Kbits per second, it requires over 40 seconds to transfer 20K of data from one device to another. During this transfer time, the devices have to be held together. Further, most NFC tags can hold no more than a few hundred bytes of data, except for the most expensive ones, which can hold 1K or 4K of data.
- File sharing over NFC uses Bluetooth or Wi-Fi connection handover. Connection handover over NFC requires no user action; however, the sending and receiving devices must both support either Bluetooth or Wi-Fi.
- Content cannot be streamed using NFC.
NFC Forum tag reader and writer
A BlackBerry 10 device can read from or write to any tag that the NFC Forum supports. As a reader, the device detects the tag, reads the NDEF message stored on the tag, and notifies the interested application for processing. To be able to read an NDEF message from an NFC tag, an app must register its interest in that type of message.
An NDEF message may contain multiple records, and an NFC tag may contain two NDEF messages. In each case, an app is launched according to the following logic:
- One NDEF message with multiple records: NFC looks for an application registered for the first record type. If it is found, the app is notified and handles the message. If no app is registered to handle the first record, NFC continues on to the next record. For example, an NDEF message may contain two records: a proprietary Type Name Format (TNF) for the first record and a link to the BlackBerry World storefront for the second record. The link to the BlackBerry World storefront allows users to download the app.
- Two NDEF messages with one record each: NFC acts on both messages
simultaneously. An example use case is:
- The first NDEF message contains credentials for setting up a Bluetooth connection and is dispatched to an app to establish a connection with a Bluetooth headset.
- The second NDEF message is dispatched to a separate handler, which responds by launching an app to play music using the Bluetooth connection.
Supported NFC tags
The BlackBerry 10 devices support the following NFC Forum compliant tags:
|NFC Forum tag type||Supported tags|
ISO 15693 tag reader and writer
The BlackBerry 10 device can also read and write to ISO 15693 tags.
To read an ISO 15693 tag, register for tag detection events by calling nfc_register_tag_readerwriter(TAG_TYPE_ISO_15693_3). To write to an ISO 15693 tag, use nfc_tag_transceive().
Working with the mimeType, uri, and data properties
If you want to use Cascades to share an NDEF message, set the MIME-type of that content to application/vnd.rim.nfc.ndef. The mimeType, uri, and data properties are exposed in the following way:
- If you want to share content using an NFC Share Card and QML, define the mimeType, uri, and data properties in the query element of the InvokeActionItem.
- If you want to share content using an NFC Share Card and C++, define the mimeType, uri, and data properties in the InvokeRequest.
- If you use the NFC Share API instead of an NFC Share Card to share content, define the mimeType, uri, and data properties either in an instance of the NfcShareDataContent class (when sharing data), or in an instance of the NfcShareFilesContent class (when sharing files), and then pass the instance to the NfcShareManager::setShareContent() function.
Working with the NFC C API
If you want to use the NFC service C API (libnfc and libnfc_bps) to send or receive content, you must first connect to the NFC system and then register with the NFC service for the types of NFC events you are interested in. Failure to connect to the NFC system will result in the NFC_RESULT_SERVICE_CONNECTION_ERROR.
- Connecting directly using nfc_connect(). You can read NFC events using nfc_read_event().
- Registering with the BlackBerry Platform Services (BPS) using nfc_request_events(). The libnfc_bps library manages the NFC connection for your app and delivers NFC events to the app.
- To read or write to an NFC tag, register for tag detection events using nfc_register_tag_readerwriter() and pass in the particular type of tag (defined in nfc_tag_type_t) your app is interested in as a parameter.
- To be notified of LLCP connections from another NFC device, register this interest using nfc_register_snep_client().
- To send a large file using Bluetooth or Wi-Fi connection handover, register to receive handover events using nfc_register_handover_listener(). Handover events are defined in nfc_event_type_t.
Last modified: 2015-07-24