## Building
### Verify your phone is compatible
All Android O (8.1, API level 27) and later devices are
compatible with Matter. Follow the steps below to check if
your phone has the necessary modules.
#### Set up Android Debug Bridge
> [!NOTE]
> **Note:** Android Debug Bridge is not supported for the Google Nest Hub or Google Nest Hub Max, both of which run the Fuchsia OS.
Android Debug Bridge (`adb`) should be set up prior to troubleshooting.
To set it up:
1. [Install "adb" on your
computer](https://developer.android.com/studio/releases/platform-tools).
2. [Turn on Developer Options and USB
Debugging](https://developer.android.com/studio/debug/dev-options#enable) on your Android phone.
#### Verify your Google Play Services (GPS) Matter modules
To check if you have the Google Play services Matter
modules, do the following:
1. [Set up Android Debug Bridge](https://developers.home.google.com/matter/troubleshooting.md.txt#android_debug_bridge_setup).
2. Use a USB cable to connect your Android phone to your computer.
3. Run this command in a terminal to verify that the necessary Matter modules are installed:
adb shell dumpsys activity provider com.google.android.gms.chimera.container.GmsModuleProvider | grep "com.google.android.gms.home"
If you see output similar to the below, you have the Matter modules installed:
```
com.google.android.gms.home [v222110900]
```
Note that the version number above may be different from your device.
4. Run this command in a terminal to verify that the necessary Thread modules are installed:
adb shell dumpsys activity provider com.google.android.gms.chimera.container.GmsModuleProvider | grep "com.google.android.gms.threadnetwork"
If you see output similar to that in the following example, you have the Thread modules installed:
```
com.google.android.gms.threadnetwork [v222106301]
```
Note that the version number on your device may be different.
If the modules are not listed, it means that either:
1. You have an outdated Android version. Make sure it's Android O (8.1) or above.
2. The Matter modules have not been downloaded yet. Wait at least 24 hours for them to download. Ensure your device is powered on and charging during this time, so the download isn't delayed. If you haven't received the modules within 24 hours, you can try a factory data reset of the device to force the modules to download.
### Verify the VID/PID of your device
If you want to start developing your integration with Google, you must create a
project and an integration on the Google Home Console.
> [!NOTE]
> **Note:** For *production* devices, the Google Home ecosystem supports commissioning and control of certified Connectivity Standards Alliance (Alliance) devices regardless of whether they have a project in the Google Home Console.
The VID/PID value your device is beaconing should match the VID/PID
entered into your Google Home Developer Console project.
- **VIDs `0xFFF1` --- `0xFFF4` are reserved for testing.** They may be used for basic commissioning and control tests, but they can't be used during the following phases of development:
- [Test](https://developers.home.google.com/matter/test.md.txt)
- [Field Trial](https://developers.home.google.com/matter/field-trial.md.txt)
- [OTA](https://developers.home.google.com/matter/ota.md.txt)
Using a Bluetooth engineering app such as
[nRF Connect for Mobile](https://play.google.com/store/apps/details?id=no.nordicsemi.android.mcp),
you can see the VID/PID of the beaconing device in the **Service Data** field.
In this screenshot from the Android version of nRF Connect,
you'll see the VID/PID is listed as `5A23FFFE` starting at the fourth byte of
the **Service Data** field. This indicates a VID of `5A23` and a PID of `FFFE` ---
both in **little endian format**.
**The BLE app displays the values in little endian,** but the VID/PID values
you enter into your Developer Console project are in big endian.
Validate that the right values and format have been entered into your Actions
Console project based on what the Bluetooth sniffer is showing.
For the values in the example screenshot, the VID and PID in the
Developer Console would be `235A` and `FEFF`, respectively.
> [!NOTE]
> **Note:** The VID of `235A` should no longer be used in your project and is used here for illustrative purposes. Make sure you're using a VID as per the Matter Specification, or one of the test VIDs as noted on the [Create a Matter integration](https://developers.home.google.com/matter/integration/create.md.txt#vendor_id) page.
### Verify your device was built using a compatible Matter SDK branch
Google Matter hubs are compatible with
Matter 1.0 and have been tested with builds that used
commits from the stable branch `v1.0-branch`. Check the [Public release
notes](https://developers.home.google.com/matter/release-notes) for the specific commits recommended for use with
each new hub release.
## Pairing
### Verify the credentials for your device
When you use your own *Alliance-assigned VID* , ensure that you
have the *correct credentials on the device*:
- Certification Declaration (CD).
- Device Attestation Certificate (DAC) and its certificate chain.
For more information, see [Create Matter device test
certificates](https://developers.home.google.com/matter/build/certificates).
### Verify your Matter-compatible Hub
Your Matter hub must be one of the [hubs supported by
Google](https://developers.home.google.com/matter/supported-devices#hubs). It must also be on a
[*build* compatible with Matter](https://developers.home.google.com/matter/release-notes.md.txt).
[Some hubs are also
**Thread Border Router (TBR)s**](https://developers.home.google.com/matter/supported-devices#hubs)
and thus enable you to develop and test [Thread](https://developers.home.google.com/thread.md.txt) devices. Other hubs
only support Wi-Fi and Ethernet Matter devices, unless you
have another border router in your network to enable Thread
connectivity.
Your hub build may be verified by: **Sliding finger down from top edge \>
Configuration Wheel \> Device Information \> Technical information \>
Chromecast firmware version**
### Commissioning fails with a "Could not contact Google" error message
Make sure you have created an integration with the correct VID/PID combination
in the Developer Console. See [Create a Matter
integration](https://developers.home.google.com/matter/integration/create) for more information.
### Commissioning fails with a "Can't reach device" error message
If you keep getting a "Can't reach device" error message when commissioning a
Thread device, and have exhausted all the available debug
options, you may want to clear the stored preferred Thread
credentials on your Android phone for a clean setup via **Settings \> Apps \>
App Apps' \> Google Play services \> Storage \& cache \> Manage space \>
CLEAR ALL DATA**.
## Testing
### Commissioned device does not appear in the Test Suite
If you've paired a device with a test Vendor ID (VID) and Product ID (PID), but
it does not appear when you attempt to [test the device with the Test
Suite](https://developers.home.google.com/matter/test) in Developer Console, this is likely caused by
using the same test VID and PID combo across multiple integrations.
To troubleshoot, remove all test devices from Developer Console and pair
the device you wish to test again.
To validate that you've paired the correct one, you can set the Manufacturer and
Model information (`CHIP_DEVICE_CONFIG_DEVICE_*` values) for the device to
unique values in your test firmware.
See [Device information](https://developers.home.google.com/matter/integration/pair.md.txt#device_information) for more
information.
## If things still go wrong
If after following all the troubleshooting steps here your issue still isn't
solved, no problem!
In the troubleshooting steps you have gathered important data about your device,
console project, and environment. With that data in hand check the
[Support page](https://developers.home.google.com/matter/support.md.txt), for how to best share your issue with the
community and the Google Home support team.