3 - Data Formats
eDynamo| Secure Card Reader Authenticator | Programmer’s Manual (COMMANDS)
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D998200115-17
)
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)
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
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
.
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
.
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
for card data, and section
