This example requires one of the following SoftDevices: S112, S132, S140

Important: Before you run this example, make sure to program the SoftDevice.

The ANCS Client Application is an example that implements an Apple Notification Center Service client. This client receives iOS notifications and is therefore a Notification Consumer. It can be connected with a Notification Provider, typically an iPhone or some other Apple device, which functions as ANCS server. The application uses the GATT Service Client to look for an ANCS server whenever there is a change in the services on the peer device.

For detailed information about the Apple Notification Center Service, see Apple's iOS Developer Library.

When the application is connected to a Notification Provider, it receives and prints incoming notifications on the UART. Pressing Button 1 requests the attributes of the last received notification. For example, if the notification indicates a new email, notification attributes contain the app identifier, the title of the email, the actual message, the sent date, and so on. Pressing Button 2 requests the attributes of the app that sent the notification (currently, the app attributes contain only the name of the app). If any attributes are received, they are printed to the UART.

Notifications can have positive and negative actions associated with them, depending on the app that is sending the notification. For example, a notification for an incoming call is usually associated with the positive action to answer the call and the negative action to reject it. After receiving a notification, the available actions are indicated by flags on UART. Push Button 3 to perform the positive action as response to the notification, or Button 4 to perform the negative action.

Note: This application is not power optimized!; The application will stop advertising after 3 minutes and 30 seconds and go to system-off mode. Push Button 1 to restart advertising.

Setup

You can find the source code and the project file of the example in the following folder: <InstallFolder>\examples\ble_peripheral\ble_app_ancs_c

Button assignments - in addition to those defined in BSP BLE Button Assignments:

During connection:
Button 1: Request iOS notification attributes (content) on UART.
Button 2: Request iOS app attributes on UART.
Button 3: Perform a positive action as response to the last received notification.
Button 4: Perform a negative action as response to the last received notification.

Testing with an iOS device

Perform the following steps to test the ANCS Client Application with an iOS device (for example, an iPhone):

Start a terminal emulator like PuTTY and connect to the used COM port with the following UART settings:
- Baud rate: 115.200
- 8 data bits
- 1 stop bit
- No parity
- HW flow control: None
Compile and program the application. Observe that the BSP_INDICATE_ADVERTISING state is indicated.
Select the device in the iOS settings -> Bluetooth menu and connect.
Observe that the BSP_INDICATE_CONNECTED state is indicated.
Observe that notifications that are displayed in the iOS notification tab also show up on the UART from the example application.
Press Button 1 to retrieve the notification attributes and observe that you receive, among other information, the app identifier for the last received notification. For example, if you got a notification from the Calendar app and request the app identifier, it is "com.apple.mobilecal".
Press Button 2 to retrieve the app attributes and observe that you receive the display name for the app identifier from the previous step. For example, requesting the app attributes for "com.apple.mobilecal" yields "Calendar".
If the notification has a flag for a positive or negative action, perform the notification action with Button 3 or Button 4, respectively.

Testing with nRF Connect

You can also test the application by emulating an iOS device with nRF Connect. To do so, perform the following steps (see the respective sections for detailed information):

Establish a connection

Start a terminal emulator like PuTTY and connect to the used COM port with the following UART settings:
- Baud rate: 115.200
- 8 data bits
- 1 stop bit
- No parity
- HW flow control: None
Compile and program the application. Observe that the BSP_INDICATE_ADVERTISING state is indicated.
In nRf Connect, create the Apple Notification Center Service (ANCS) server by completing the following steps:
- In Server Setup, click the settings button and select "Load setup".
- In the resulting window, navigate to the <InstallFolder>\examples\ble_peripheral\ble_app_ancs_c folder. Load the file ANCS_central.ncs.
- Click "Apply to device" and navigate back to Connection Map.
Bond to the device from nRF Connect (the device is advertising as 'ANCS'). To bond, click the settings button for the server in nRF Connect, select "Security parameters", check "Perform Bonding", and click "Apply". Then connect to the device.
Observe that the BSP_INDICATE_CONNECTED state is indicated.
After bonding, verify in the Server setup that the Client Characteristic Configuration descriptors (CCCD) for ANCS Notification Source (0x120D) and ANCS Data Source (0xC6E9) are set to '01 00'.

Send an iOS notification to the application

The following table shows the format of a notification that you can send to the example application:

Field	Example value	Interpretation
Event ID	0	Notification added
Flags	18	Positive/negative action
Category	06	Email
Category count	02
Notification UID	01 02 03 04	67305985 (0x4030201)

In nRF Connect, set the value of ANCS Notification Source (characteristic 0x120D) to '00 18 06 02 01 02 03 04' and click Update.

Verify that the UART data is received as follows:

    Notification
    Event:       Added
    Category ID: Email
    Category Cnt:2
    UID:         67305985
    Flags:
     Positive Action
     Negative Action

Perform a notification action

The received notification has two flags: Positive Action and Negative Action. This means that you can perform these two actions on the notification.

The following table shows the format of the message that the application must send back to perform a notification action:

Field	Example value	Interpretation
Command ID	2	Perform notification action
Notification UID	01 02 03 04	67305985 (0x4030201)
Action	00 01	Positive Negative

Press Button 3 to perform a positive action and verify that the ANCS Control Point (0xD8F3) is updated to '02 01 02 03 04 00'.
You can also press Button 4 and observe that the server receives a negative action (02 01 02 03 04 01).

Retrieve notification attributes

The following table shows the relevant part of a request to retrieve notification attributes:

Field	Example value	Interpretation
Command ID	0	Get notification attributes
Notification UID	01 02 03 04	67305985 (0x4030201)
Attribute ID	00	App identifier
Attribute ID	01	Title
Length	20 00	0x0020
Attribute ID	03	Message
Length	20 00	0x0020

Note that the example application will request all existing attribute types, not only a subset.

The following table shows the format of a response that contains some of the requested notification attributes:

Field	Example value	Interpretation
Command ID	0	Get notification attributes
Notification UID	01 02 03 04	67305985 (0x4030201)
Attribute ID	01	Title
Length	03 00	0x0003
Data	6E 52 46	"nRF"
Attribute ID	03	Message
Length	02 00	0x0002
Data	35 32	"52"
Attribute ID	00	App identifier
Length	03 00	0x0003
Data	63 6F 6D	"com"

Press Button 1 to request notification attributes for the iOS notification that was received.
In nRF Connect, verify that the ANCS Control Point (0xD8F3) is updated to '00 01 02 03 04 00 01 20 00 02 20 00 03 20 00 04 05 06 07'.
Respond to the request by sending two notification attributes: the title and the message. To do this, first set the Data Source (characteristic 0xC6E9) in the Server to '00 01 02 03 04 01 03 00 6E 52 46 03 02 00 35 32'.
The application will print the received data on UART. Verify that the UART output is as follows:
```
   Title: nRF
   Message: 52
```
Update the Data Source again with the app identifier '00 03 00 63 6F 6D'.
Verify that the notification is received and the UART output is as follows:
```
   App Identifier: com
```

Retrieve app attributes

With the app identifier, you can request attributes of the app that sent the notification.

The following table shows the format of a request to retrieve app attributes:

Field	Example value	Interpretation
Command ID	1	Get app attributes
App identifier	6D 6F 63 00	"com" + '\0'
Attribute ID	0	Display name

The following table shows the format of a response that contains the requested app attributes:

Field	Example value	Interpretation
Command ID	1	Get app attributes
App identifier	63 6F 6D 00	"com" + '\0'
Attribute ID	0	Display name
Length	04 00	0x0004
Data	4D 61 69 6C	"Mail"

Press Button 2 to request app attributes for the app with the app identifier "com" (the last received app identifier).
In nRF Connect, verify that the ANCS Control Point (0xD8F3) is updated to '01 63 6F 6D 00 00'.
Respond to the request by sending the app attribute. To do this, set the Data Source (characteristic 0xC6E9) in the Server to '01 63 6F 6D 00 00 04 00 4D 61 69 6C'.
The application will print the received data on UART. Verify that the UART output is as follows:
```
    Display Name: Mail
```

Disconnect

Disconnect the device in nRF Connect and observe that the BSP_INDICATE_ADVERTISING_WHITELIST state is indicated.
Wait until the application goes to system-off (BSP_INDICATE_IDLE).
Press (and hold) Button 1 and reconnect to nRF Connect. Observe that the BSP_INDICATE_CONNECTED state is indicated.
Disconnect from nRF Connect.