Troubleshooting Bluetooth Low Energy
If you are having issues connecting to your Bluetooth® Low Energy peripheral device from MATLAB® or are unable to read or write data, you can try some of the following troubleshooting tips.
Check Supported Platforms
The Bluetooth Low Energy interface is supported on these platforms:
macOS 10.13 High Sierra or later
Windows® 10, version 1709 or later
Before trying other troubleshooting steps, make sure your computer is running one of these platforms.
If MATLAB does not detect your built-in or external Bluetooth adapter when you call
blelist, try the following:
Make sure the adapter supports Bluetooth 4.0 and higher.
Restart Bluetooth services on your computer.
Update to the latest device drivers for your adapter.
Reboot your computer.
Check Device Status
If your device does not appear in the
blelist output, make sure
that you have done the following:
Power on your peripheral device.
Bring your peripheral device within range of your computer.
Disconnect your peripheral device from any other devices or applications first. The output from
blelistshows you only nearby devices that are currently advertising data. If your device is already connected in another application or in MATLAB, it might not appear in the output.
Try a larger value for the
blelist. This increases the amount of time MATLAB scans for nearby devices. For example,
blelist("Timeout",20)searches for nearby peripheral devices for 20 seconds. The default timeout value is three seconds. If your device transmits advertisement data less often than once every three seconds, MATLAB might not capture it.
If your peripheral device powers off or disconnects, the UUID might change when it
powers on again or reconnects. However, the name remains the same in the
blelist output. If you are trying to create a new
ble object for the same device, specify the new UUID instead of the
On Windows, if a peripheral device has already been paired but the firmware that
defines characteristics and descriptors is changed,
ble might fail to
connect the device to your computer. To fix this, disconnect and then reconnect your
device to Windows.
If you are unable to create a
characteristic object for your
Bluetooth Low Energy device on Windows 10, try pairing your device on Windows before using
ble to connect to it in MATLAB. You can pair to a device in Windows Settings > Devices > Add Bluetooth or other device.
Enable Bluetooth Permissions on macOS Big Sur
If you are using macOS Big Sur, you may need to configure additional settings. Try the following steps when you get this error message:
Bluetooth permission is not enabled for MATLAB. Allow MATLAB or Terminal to
use Bluetooth from the Security & Privacy settings.
Open Security & Privacy > Privacy > Bluetooth and click the + icon.
If you launch MATLAB from Applications, add MATLAB to the list of apps that are allowed Bluetooth access.
If you launch MATLAB from Terminal, add Terminal to the list of apps that are allowed Bluetooth access.
If you launch MATLAB from both Applications and Terminal, add both MATLAB and Terminal to the list of apps that are allowed Bluetooth access.
Troubleshoot Read and Write Operations
read(c) inside a
callback function for a characteristic with a high rate can throw an error or block
MATLAB for a long time. Instead, use
read(c,'oldest') in a
callback function. For an example, see Read Characteristic Data from a Bluetooth Low Energy Peripheral Device Using a Callback Function.
On macOS, some device characteristics require authentication to read or write for the
first time. After you create a
ble object, run
write. Follow the prompts that appear on your computer to pair your