Automated tests

Automated tests allow you to configure and run set of tests foor your Bluetooth Smart device using an Android 4.3+ phone. Feel free to submit comments, bugs or feature ideas.

Resources

1. test.bat - the Windows script that may be used to run the test on the Android device.
2. sample_test_hrm.xml - one of the sample tests. It covers almost all features of the automated tests, except those added in nRF Connect 4.3 or later. It can be run on the HRS_DFU sample application from the SDK. You may modify it to match your application.
3. sample_test_scanning.xml - the second sample test. Covers new scanning feature in automated tests added in nRF Connect v. 4.3.

How to begin

The automated tests should work with any Bluetooth Smart device that communicates over the GATT protocol. A test XML can be created to test that the services, characteristics and descriptors have the correct values and behaviour. A Device Firmware Update (DFU) also may be performed.

To make an easy start the sample_test_hrm.xml file contains a test that can be used with the HRS_DFU sample from the SDK. The instruction below describes steps that should be performed to successfully run this test.

Note: Starting from the SDK 8.0, the DFU bootloader, in case the buttonless update is NOT being used, advertises with a device address increased by 1. Therefore, the test may fail in the first run if you have just the Soft Device and Bootloader flashed on the device. After flashing the HRS application onto it, it will start to advertise with a different address and a timeout will be thrown during connection attempt. But the test should work for the second time as the bootloader uses the same address if buttonless update is in use.

1. nRF Connect (nRF Master Control Panel v2.1 or newer) will create the above files in your phone's file system in /Nordic Semiconductor folder. Note: Newly created files may not be visible on the PC when connected with USB. This is beacuse Android must perform a scan of media files. Get the files from GitHub or trigger the media scanner manually: restart the phone/tablet or install and launch the Rescan SD application (or similar) from Google Play.

2. Copy the above mentioned files to your PC. You will use the test.bat to start the testing service. The sample may be used as a demo or a starting point.

3. Prepare the nRF51 DK for the test flash with the Soft Device and the DFU bootloader. Note: This change is not required for newer versions of the DFU bootloader.

4. Flash the Soft Device s110 version 8.0 or newer (for example using nRF Go Studio).

5. Flash the DFU Bootloader from SDK 9.0 or newer (both SD and Bootloader are available on http://developer.nordicsemi.com website). - If you want to use the buttonless update in DFU bootloader from SDK 7.1, modify the dfu_transport_ble.c file in your bootloader source (you may have to unlock the file in Explorer first as it's READ ONLY by default). - Increase the APP_DIRECTED_ADV_TIMEOUT value to 50 (it's 5 by default) in line 62: #define APP_DIRECTED_ADV_TIMEOUT 50 - Compile the modified Bootloader and flash the new HEX. - This change is required for Android to reconnect to the bootloader after switching the device to bootloader mode. By default, the bootloader advertises for 6 seconds (5 * 1.28s) which is shorter than the disconnection timeout on Android. Android, after sending the jump command, waits for the disconnection event for about 22 seconds, depending on the device model. Value 50 (1 minute) should be more than enough.

6. Connect your Android device to the PC, enable USB debugging on it and install required drivers and ADB (Android Debug Bridge) on the PC. Add the ABD to the PATH global variable or copy it (and dlls) to the same folder.

7. Try the ADB by writing adb devices command in the command line. A list of connected Android devices should be shown.

8. Find out the address of your device. You may use the nRF Connect to do that. Your device should advertise as a DFU Targ. Make sure you are not connected with the bootloader.

9. Optional: Install the nRF Logger application to get more information about the test progress and syntax errors.

10. Start the sample test with the following command. Use your device address, f.e. AA:BB:CC:DD:EE:FF instead of address*. The -d option is required only when more than one Android device is connected and configured for USB debugging.

    test.bat [-d your_android_device_id] -E EXTRA_ADDRESS address* sample_test_hrm.xml

11. A Test in progress... notification will be shown. If you had the nRF Logger installed click the notification to display the test progress.

12. When test is completed the sample_test_hrm_result.txt file will be created in the script location. The result of the sample HRM test is here.

To test the HRM sample test on nRF52 device you have to modify the XML script and either remove the run-test with the id dfu, or modify the FIRMWARE_PATH constant to /Nordic Semiconductor/Board/pca10040/ble_app_hrm_dfu_s132_v2_0_0_sdk_11_0.zip and make sure the Soft Device 2.0.0 and HRM_DFU app is flashed.

Scanning sample test - the second test does not require providing the device address. The test service will perform a BLE scan and find a device that advertises with HRM service UUID, connect and do some basic operations just to prove it works.

Documentation

The test suite is defined in XML in the test-suite node. The basic test suite structure is shown below:

<test-suite>
  <!-- Definitions (0+) -->
  <set name="KEY" value="VALUE" /> 
  ...
  <!-- Target(s) (0+) -->
  <target id="TARGET_ID" name="TARGET_NAME" [address="AA:DD:DR:RE:ES:SS"] />
  ...
  <!-- Test definition(s) (1+) -->
  <test id="TEST_ID" description="DESCRIPTION" [target="TARGET_ID"]>
    ...
  </test>
  ...
  
  <!-- Run test command(s) (1+) -->
  <run-test ref="TEST_ID" description="DESCRIPTION">
    <!-- Optional constants redefinition (0+) -->
    <set name="KEY" value="OTHER_VALUE" />
  </run-test>
  ...
</test-suite>

Targets

A test suite may test one or more devices. A default target may be set for the test and/or specified for each operation (see below). The operation's target, if specified, overwrites the test target. Since version 4.3 defining a target is not required (as scan operation does not require it). If set, the address may not be specified, as the new scan-for command may bind the target with an advertising device based on defined filters.

Operation expected result

Each operation in the test may end with SUCCESS, WARNING or FAIL. If the operation fails the test is aborted and the device is being disconnected. Warning does not abort the test but the cause of the warning is logged. In addition, the expected result for each operation may be specified using expected attribute. Using this attribute a test can check some conditions that should not happen. This attribute may have one of the following values:

• SUCCESS - success is required to go on (default),
• SUCCESS_WARNING_ON_FAIL - a warning will be logged in the result file but the test will continue,
• FAIL - a fail is required to proceed,
• FAIL_WARNING_ON_SUCCESS - a fail is expected but in case of a success a warning will be logged to the result file.

If expected attribute is set to FAIL the tag may also specify the expected error code using expectedErrorCode attribute. For example, if writing to a characteritistic should fail because of its CCCD not being enabled the read tag may contain expected="FAIL" expectedErrorCode="253" (GATT CCCD CFG ERROR, 0xFD). This attribute has been added in nRF Connect v.4.11.

Timeouts

Each operation, except dfu, may have the timeout specified. The default timeout for each is set to 5000ms and may be changed using the timeout="NUMBER" attribute. The number is in milliseconds.

Operations

The following operations are currently supported:

Scan

<scan [description="DESCRIPTION"] [rssi="RSSI_VALUE"] [name="NAME"] [data="ADV_PACKET_FILTER"] [target="TARGET_ID"] [timeout="NUMBER"] />

The scan command will perform a BLE scan for exactly the time given by a timeout attribute (default 5000 ms) and will list all received advertising packets matching filters in a format: TIME ADDRESS RSSI(decimal) DATA(hex) (one line per packet), for example:

12:34:56.123 11:22:33:44:55:66 -45 0B094E6F726469635F48524D0319410302010607030D180F180A18

Attributes address, rssi, data and/or target MAY be specified to filter packets by address or advertising data:

• address - scan will log packets from a device with given Bluetooth address.
• rssi - scan will log packets with RSSI value greater or equal to specified is received. RSSI values vary from around -100 dBm (far) to approx -40 dBm (very close).
• name - scan will log packets from a device with given Complete or Shortened Local Name.
• data - scan log packets matching given data in received advertising packet. Matching is done using Pattern#find(String) method after converting the adv. packet to an uppercase HEX string representation. This means, that if a device advertises with "020104" a data="10" will be found. The data attribute SHOULD contain only HEX characters, otherwise it will for 100% not match any HEX data.
• target - scan will log packets from a device with the same address as the target is found. The target must be bound before.

Scan-For

<scan-for [description="DESCRIPTION"] [rssi="RSSI_VALUE"] [name="NAME"] [data="ADV_PACKET_FILTER"] [target="TARGET_ID"] [bind-target="TARGET_ID"] [timeout="NUMBER"] />

The scan-for command will perform a BLE scan and finish when a device matching given filter parameters (address, rssi and/or advertising data) is found, or the timeout specified by the timeout attribute occur.

Attributes address, rssi, data and/or target MAY be specified to filter packets by address or advertising data:

• address - scan will continue until a device with given Bluetooth address.
• rssi - scan will continue until a packet with RSSI value greater or equal to specified is received. RSSI values vary from around -100 dBm (far) to approx -40 dBm (very close).
• name - scan will log packets from a device with given Complete or Shortened Local Name.
• data - scan will continue until given data will be found in received advertising packet. Matching is done using Pattern#find(String) method after converting the adv. packet to an uppercase HEX string representation. This means, that if a device advertises with "020104" a data="10" will be found. The data attribute SHOULD contain only HEX characters, otherwise it will for 100% not match any HEX data.
• target - scan will continue until a device with the same address as the target is found. The target must be bound before.

Attribute bind-target MAY be used to bind the first matching device with given target identifier. A target may be bound multiple times (but only when it's not connected), so you may reuse the test using multiple run-test commands with different filters.

Connect

<connect [description="DESCRIPTION"] [timeout="NUMBER"] [target="TARGET_ID"] />

This operation must be defined if a test should connect to the device. The only operations that do not need the connection are bond and dfu. If you forget to add the connect tag an error will occur and the test will ask you whether you forgot to connect.

The connect operation is followed by a 1 second break to give Android some time before the next operation. This second may be used f.e. for re-establishing a bond and/or starting the service discovery.

Service Discovery

<discover-services [description="DESCRIPTION"] [timeout="NUMBER"] [target="TARGET_ID"] />

To be able to assert, read or write characteristics a discover-services operation must be specified. This will cause the service discovery on the device. However, if services are already known and cached, the cached list will be returned. Please, use the refresh operation to clear the cache.

Refresh

<refresh [description="DESCRIPTION"] [timeout="NUMBER"] [target="TARGET_ID"] />

This operation clears the device services cache. It's using the hidden Android method BluetoothGatt#refresh() which may be removed from the API in the future. It may be useful when multiple different BLE applications are being flashed on the same Bluetooth Smart device (e.g. DK).

This method must be called after the device has been connected at least once in the test using the connect operation. Otherwise an error message will be shown. This is because it is being invoked on a BluetoothGatt object which is created using connectGatt(..) method.

The refresh operation is followed by a 1 second break to give Android some time before the next operation. The break may be used to start the Android-internal service discovery.

Disconnect

<disconnect [description="DESCRIPTION"] [timeout="NUMBER"] [target="TARGET_ID"] />

Each device used in the test is automatically disconnected when the test ends (no matter the result). However, when a diconnection is part of the test this operation may be used.

Assert services and characteristics

<assert-service [description="DESCRIPTION"] [target="TARGET_ID"] uuid="SERVICE_UUID" [instance-id="INSTANCE_ID"] [target="TARGET_ID"] [expected="SUCCESS"] >
  <!-- Assert the characteristic in this service -->
  <assert-characteristoc [description="DESCRIPTION"] [target="TARGET_ID"] uuid="CHAR_UUID" [instance-id="INSTANCE_ID"] [expected="SUCCESS"]>
    <!-- Assert characteristic properties -->
    <property name="NOTIFY" [requirement="MANDATORY"] />
    <!-- It may also have some other properties (this section may be skipped as this is does not do any checking -->
    <property name="READ" requirement="OPTIONAL" />
    <!-- But for sure it must not have those properties -->
    <property name="WRITE" requirement="EXCLUDED" />
    <property name="WRITE_WITHOUT_RESPONSE" requirement="EXCLUDED" />
    <!-- 
			Property name is case-sensitive and must be one of the following: 
				- BROADCAST
				- READ
				- WRITE
				- WRITE_WITHOUT_RESPONSE
				- NOTIFY
				- INDICATE
				- SIGNED_WRITE
				- EXTENDED_PROPERTIES

			Requirement name is also case-sensitive and must be one of the following:
				- MANDATORY (default)
				- OPTIONAL
				- EXCLUDED
    -->
    <property name="SIGNED_WRITE" requirement="EXCLUDED" />
    <!-- This characteristic should have the CCCD descriptor. Attribute 'instance-id' is optional -->
    <assert-descriptor [description="Checking ${DESC_NAME} descriptor"] uuid="${CCCD_UUID}" [expected="SUCCESS"] />
    <!-- We may also check if the characteristic has Client Characteristic Configuration with assert-cccd command -->
    <assert-cccd [description="Another way of checking only the CCCD"] [expected="SUCCESS"]>
      <!-- And even check the value of any descriptor, including the CCCD -->
      <assert-value [description="Check if notifications are disabled by default"] value="BYTES"|value-string="TEXT" [expected="SUCCESS"] />
    </assert-cccd>
    <!-- 
			The following descriptor should not be in this characteristic.

			An 'expected' attribute may be set to all operations (except 'property' and 'sleep') to specify the expected result.
			Expected result may be one of the following:
				- SUCCESS                 - success is required to go on (default)
				- SUCCESS_WARNING_ON_FAIL - a warning will be logged in the result file but the test will continue
				- FAIL                    - a fail is required to proceed
				- FAIL_WARNING_ON_SUCCESS - a fail is expected but in case of a success a warning will be logged to the result file.
	-->
    <assert-descriptor [description="This descriptor should not be found"] uuid="00002906-0000-1000-8000-00805f9b34fb" [expected="FAIL"] />
  </assert-characteristic>
</assert-service>

The assert-service operation and its child nodes may be used to validate the proper configuration of the device. For all assert operations an expected attribute may be specified (see above).

Remember that before you read the characteristic its value is null (null is equal to 00+, as on the example above or to an empty string). The only exceptions are the CCCD descriptors for bonded devices. When notifications or indications were enabled in the previuos connection the value of the descriptor is saved in the application's database and will not change. However, there is no guarantee that that is the real value of the descriptor on the target device unless the read-descriptor operation will be executed.

The value may be given in bytes using the value attribute, or as a string using value-string.

Bond

<bond [description="DESCRIPTION"] [timeout="NUMBER"] [target="TARGET_ID"] [expected="SUCCESS"] />

Bonds to the device. This operation may be called even when the device is not connected.

Unbond

<unbond [description="DESCRIPTION"] [timeout="NUMBER"] [target="TARGET_ID"] [expected="SUCCESS"] />

Removes the bond information from the phone/tablet. This operation may be called even when the device is not connected and will cause disconnection when invoked on connected device.

Read characteristic

<read [description="DESCRIPTION"] service-uuid="SERVICE_UUID" [service-instance-id="SII"] characteristic-uuid="CHAR_UUID" [characteristic-instance-id="CIU"] [timeout="NUMBER"] [target="TARGET_ID"] [expected="SUCCESS"]>
  <!-- Assert characteristic value -->
  <assert-value [description="DESCRIPTION"] value="BYTES"|value-string="TEXT" [expected="SUCCESS"] />
</read>

The read operation reads the value of the characteristic. A value assertion may be defined as a child node.

The instance-id attributes are optional and set to 0 by default.

Read descriptor

<read-descriptor [description="DESCRIPTION"] uuid="DESCRIPTOR_UUID" service-uuid="SERVICE_UUID" [service-instance-id="SII"] characteristic-uuid="CHAR_UUID" [characteristic-instance-id="CII"] [timeout="NUMBER"] [target="TARGET_ID"] [expected="SUCCESS"]>
  <!-- Assert characteristic value -->
  <assert-value [description="DESCRIPTION"] value="BYTES"|value-string="TEXT" [expected="SUCCESS"] />
</read-descriptor>

Reads the value of the descriptor with given UUID and asserts its value.

The instance-id attributes are optional and set to 0 by default.

Write characteristic

<!-- 
  The type value is case-sensitive and may have one of the following values:
  - WRITE_REQUEST (default) - Write With Response
  - WRITE_COMMAND - Write Without Response
-->
<write [description="DESCRIPTION"] service-uuid="SERVICE_UUID" [service-instance-id="SII"] characteristic-uuid="CHAR_UUID" [characteristic-instance-id="CII"] [type="TYPE"] value="BYTES"|value-string="TEXT" [timeout="NUMBER"] [target="TARGET_ID"] [expected="SUCCESS"] />

Writes the given value to the characteristic.

The instance-id attributes are optional and set to 0 by default.

Write descriptor

<write-descriptor [description="DESCRIPTION"] uuid="DESCRIPTOR_UUID" service-uuid="SERVICE_UUID" [service-instance-id="SII"] characteristic-uuid="CHAR_UUID" [characteristic-instance-id="CII"] value="BYTES"|value-string="TEXT" [timeout="NUMBER"] [target="TARGET_ID"] [expected="SUCCESS"] />

Writes the given value to the descriptor.

The instance-id attributes are optional and set to 0 by default.

Reliable Write

Reliable Write is described in Bluetooth Core Specification v5.0, Vol 3, Part G, chapter 4.9.5. In order to start the sub-procedure (supported from Android 4.3 and nRF Connect 4.21.0), use:

<begin-reliable-write [description="DESCRIPTION"] />

All following write requests will use Prepare Write, instead of Write procedure. The target device will reply received data back to the Android for verification. If received data is different than the one sent, an assert error will be reported. Multiple characteristics may be written multiple times during a single Reliable Write operation. Other operations may also be performed while ongoing reliable write. However, at least one Write operation must be performed before executing or aborting the Reliable Write sub-procedure.

When all data are sent and verified, use:

<execute-reliable-write [description="DESCRIPTION"] [timeout="NUMBER"] [target="TARGET_ID"] [expected="SUCCESS"] />

or

<abort-reliable-write [description="DESCRIPTION"] [timeout="NUMBER"] [target="TARGET_ID"] [expected="SUCCESS"] />

to revert to a state from before the sub-procedure was started.

Notifications / indications

<assert-notification [description="DESCRIPTION"] service-uuid="SERVICE_UUID" [service-instance-id="SII"] characteristic-uuid="CHAR_UUID" [characteristic-instance-id="CII"] [timeout="NUMBER"] [target="TARGET_ID"] [expected="SUCCESS"]>
  <!--
    Before the notification will be received you may want to send or read a characteristic or descriptor.
    By doing it here you ensure that the notification listener will be initiated before sending the value, as the reply may be too fast.
    If the 'write' operation was executed before calling the 'assert-notification', the notification could have been
    received before this operation was started and thous the test could fail.

    The following operations may be called here: write, write-descriptor, read, read-descriptor.
    Example:
  -->
  <!--<write description="Write notification trigger" service-uuid="some UUID" characteristic-uuid="some other UUID" value="012345" />-->

  <!-- Assert characteristic value -->
  <assert-value [description="DESCRIPTION"] value="BYTES"|value-string="TEXT" [expected="SUCCESS"] />
</assert-notification>

Waits NUMBER of milliseconds for a notification from a characteristic with given parameters. A value assertion may be used to check its value.

The instance-id attributes are optional and set to 0 by default.

To ensure the notification is sent after another command is executed put this command inside the notification tag. The following operations are supported (since nRF MCP 4.1): write, write-descriptor, read, read-descriptor.

Read RSSI while connected

<read-rssi [description="DESCRIPTION"] [timeout="NUMBER"] [target="TARGET_ID"] [expected="SUCCESS"]>
  <!-- Assert RSSI value range -->
  <assert-value [description="DESCRIPTION"] value="NUMBER (e.g. -50)|LESS THNN (e.g. -50-)|GREATER THAN (e.g. -50+)" [expected="SUCCESS"] />
</read-rssi>

Reads the RSSI value of the given (or default) target. The RSSI value may be validated using the assert-value tag. In order to check whether the device signal is strong use value="-50+" attribute. The test will pass if the RSSI is higher (the signal is stronger) than -50 dBm. Be aware that the RSSI value may vary from test to test. Using a expected="SUCCESS_WARNING_ON_FAIL" is recommended.

The device must be connected. To read RSSI from not connected devices use scan operation.

Request MTU change

<request-mtu [description="DESCRIPTION"] value="MTU" [timeout="NUMBER"] [target="TARGET_ID"] [expected="SUCCESS"]/>

Sends a MTU change request to the peripheral. MTU value must be between 23 and 517 inclusive.

Note: Supported only on Android 5 and never devices.

Request Connection Priority change

<!-- 
  Property type is case-sensitive and must be one of the following: 
  - LOW_POWER (Conn interval: 100-125ms, slave latency: 2, supervision timeout multiplier: 20)
  - BALANCED (default) (Conn interval: 30-55ms, slave latency: 0, supervision timeout multiplier: 20)
  - HIGH (Conn interval: 11.25-15ms on Android 6+ or 7.5-10ms before, slave latency: 0, supervision timeout multiplier: 20)
-->
<request-connection-priority [description="DESCRIPTION"] type="TYPE" [timeout="NUMBER"] [target="TARGET_ID"] [expected="SUCCESS"]/>

Requests the change of connection priority. Only the 3 given values are supported by Android API.

Until Android 8 this is not an asynchronuous method ending always with a success, unless a serious problem occurred. It does not mean that the requested parameters have been set. From Android 8 there is a callback onConnectionUpdated, but it may be called with different parameters than requested. The operation will be assumed failed only if the status is different to GATT_SUCCESS.

Note: Supported only on Android 5 and never devices.

Read PHY

<read-phy [description="DESCRIPTION"] [timeout="NUMBER"] [target="TARGET_ID"] [expected="SUCCESS"] >
  <!--
    Assert PHY.
    Transmitter and Received PHY attributes accept the following values and logical OR operator ('|'):
    - LE_1M - legacy LE 1M PHY, 
    - LE_2M - double speed, Bluetooth 5 feature
    - LE_CODED - long range, Bluetooth 5 feature

    At least one of 'tx' or 'rx' must be set.
    For example, a valid assert may look like this: <assert-value tx="LE_2M | LE_CODED" rx="LE_1M" />
  -->
  <assert-value [description="DESCRIPTION"] [tx="TRANSMITTER_PHY"] [rx="RECEIVER_PHY"] [expected="SUCCESS"] />
</read-phy>

Reads the current PHY used for the transmitter and receiver. A value assertion may be used to check received PHYs.

Note: Reading PHY is supported only on Android 8 and newer devices.

Set Preferred PHY

<!-- 
  Transmitter and Receiver PHY attributes accept the fofflowing values and logical OR operator ('|'):
    - LE_1M - legacy LE 1M PHY (default), 
    - LE_2M - double speed, Bluetooth 5 feature,
    - LE_CODED - long range, Bluetooth 5 feature.

    The options for the Transmitter LE Coded PHY are:
    - NO_PREFERRED - No preferred coding when transmitting on the LE Coded PHY (default),
    - S2 - Prefer the S=2 coding to be used when transmitting on the LE Coded PHY,
    - S8 - Prefer the S=8 coding to be used when transmitting on the LE Coded PHY. 

    Example: <set-preferred-phy tx="LE_2M | LE_CODED" rx="LE_1M" />
 -->
<set-preferred-phy [description="DESCRIPTION"]  [tx="TRANSMITTER_PHY"] [rx="RECEIVER_PHY"] [option="OPTIONS"] [timeout="NUMBER"] [target="TARGET_ID"] [expected="SUCCESS"] />

Sets the preferred PHY that is to be used for the transmitter and receiver for the connection. Please note that this is just a recommendation, whether the PHY change will happen depends on other applications preferences, local and remote controller capabilities. Controller can override these settings.

LE 1M and no preferred coding option will be used by default, when not specified.

Note: Setting PHY is supported only on Android 8 and newer devices that support LE 2M or LE Coded.

Sleep

<sleep [description="DESCRIPTION"] [timeout="NUMBER"] />

Waits a NUMBER value of milliseconds without doing anything. Always results with SUCCESS.

Sleep If

<sleep-if [description="DESCRIPTION"] service-uuid="SERVICE_UUID" [service-instance-id="SII"] characteristic-uuid="CHAR_UUID" [characteristic-instance-id="CII"] value="BYTES"|value-string="TEXT" [timeout="NUMBER"] [target="TARGET_ID"] [expected="SUCCESS"]/>

Waits if value of the given characteristic is equal to the given one. Timeout may be set to force stop waiting. The default timeout equals 0 (no timeout). A value containing only 0s is equal to no value. If the characteristic value was different than the one given when operation started the operation ends immediately. Notifications should be enabled for the given characteristic (otherwise the value can't change).

Sleep Until

<sleep-until [description="DESCRIPTION"] service-uuid="SERVICE_UUID" [service-instance-id="SII"] characteristic-uuid="CHAR_UUID" [characteristic-instance-id="CII"] value="BYTES"|value-string="TEXT" [timeout="NUMBER"] [target="TARGET_ID"] [expected="SUCCESS"]/>

Waits until value of the given characteristic is equal to the given one. Timeout may be set to force stop waiting. The default timeout equals 0 (no timeout). A value containing only 0s is equal to no value. If the characteristic value was equal to the given one when operation started the operation ends immediately. Notifications should be enabled for the given characteristic (otherwise the value can't change).

DFU - Device Firmware Update

<!-- 
  You may upload an application, bootloader, soft device or multiple files. Use 'type="X"' attribute where X may be one of the following:
  * 1 - for SoftDevice
  * 2 - for Bootloader
  * 4 - for Application
  * 0 - for auto (all from ZIP or an application) (default)
-->
<dfu [description="DFU operation"] file="${FIRMWARE_PATH}" [initFile="${FIRMWARE_INIT_PATH}"] [type="TYPE_NUMBER"] [target="TARGET_ID"] [expected="SUCCESS"] />

The dfu operation sends the firmware Over-the-Air to the target using DFU. In case of a DFU Bootloader from SDK 7.0+ the init file is required. Check the [How to create Init file for DFU](../init packet handling/README.md) for details.

The script may send the Soft Device, Bootloader or the application, or any combinations of those packed in a ZIP file. The new Distribution packets are recommended since nRF Connect version 3.0 (known as nRF Master Control Panel at that time), however you may also use the ZIP file that contains the following content in order to be parsed correctly: