How To Receive Data On The Bluetooth Le Connection; Data Formats; How To Use Hid Format (Hid Only) - Magtek eDynamo Programmer's Manual

3 - Data Formats

2.2.4 How to Receive Data On the Bluetooth LE Connection

This section describes how the device sends unsolicited messages (messages that are not the direct
response to a command) to the Bluetooth LE host. This includes Magnetic Stripe Card Data Sent from
Device to Host (MSR Only | Keypad Entry Only), and Notification Messages Sent from Device to
Host (Extended Notifications Only).
Some of the details in this section may be abstracted by the libraries in the development framework used
to write the host software. For general information about Bluetooth LE and the associated terms, see the
Bluetooth specifications found at https://www.bluetooth.org/Technical/Specifications/adopted.htm.
In the normal operating mode for the device in GATT HID Vendor Defined mode, the device is always
advertising when not connected. The Bluetooth LE host is responsible for optimizing the device's power
consumption by only connecting when needed. If the Bluetooth LE host is not able to disconnect directly
through its Bluetooth LE API, it can force the device to disconnect by using Bluetooth LE Command
0x0B - Terminate Bluetooth LE Connection.
To receive card data when the Card Data characteristic is configured to send notifications, the host
software should do the following:
1) Make sure it is connected to the device (see section 2.2.2 How to Connect to a Device Using
Bluetooth LE).
2) Wait to receive a Card Data notification.
3) If the block identifier is not equal to 0xFF (no more card data), all card data has been received.
Otherwise, continue to wait to receive more Card Data notifications.
4) Verify the number of card data blocks received equals the number of card data blocks sent field
contained in the last notification message. A mismatch indicates a transmission error occurred.
5) Interpret the data according to section 3.2 How to Use GATT Format (GATT Only).
To receive card data when the Card Data characteristic is not configured to send notifications, the host
should do the following:
1) Make sure it is connected to the device (see section 2.2.2 How to Connect to a Device Using
Bluetooth LE).
2) Wait to receive a Data Ready notification with the characteristic identifier set to 1 (card data).
3) If the length field of the Data Ready notification is greater than zero, read the block of card data
from the card data characteristic.
4) Write the data read status characteristic with the characteristic identifier, block identifier, and read
status of the card data block that is done being read.
5) If the length field of the data ready notification is less than 512, all data has been received.
Otherwise, loop back to receive more data ready notifications with characteristic identifier set to 1.
6) Interpret the data according to section 3.2 How to Use GATT Format (GATT Only).
3 Data Formats
3.1

How to Use HID Format (HID Only)

When the device and host are communicating in vendor-defined HID mode, data comes from the device
as described in section 2.1.3 How to Receive Data On the USB Connection (HID Only). The host
software can retrieve the incoming data by examining the various usages in the report(s). For details
about which usages to examine and how to interpret the data, see section 6 Magnetic Stripe Card Data
Sent from Device to Host for card data, and section 7 Notification Messages Sent from Device to Host
(Extended Notifications Only).
eDynamo| Secure Card Reader Authenticator | Programmer's Manual (COMMANDS)
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