I am currently having some issues with connecting to my peripheral. The bluetooth module in our peripheral does not seem to be advertising a name initially. I've have found that once I connect to the peripheral for the first time it will update the name and my scanner is then able to see the correct name.
I have no understanding why this is the case. I have also tried it using the Swift app we are developing, as well as a range of Bluetooth scanners on iOS and Android so I do not believe that this is an OS or programming error on the scanner side.
Is there a specific parameter that should be set on the peripheral. As I am just the app developer I do not have very much understanding about how the module is handing the process.
Any help would be much appreciated.
Just to confirm the scanner does not see a name for the peripheral until it has connected once. After this it will start displaying the name. Once the peripherals name is changed the old name is still being displayed until I have connected to it once again.
To display the name of device you need to see in advertisementData Dictionary which contains several keys depending on your device, in callback of didDiscoverPeripheral from CentralManager.
- (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary<NSString *, id> *)advertisementData RSSI:(NSNumber *)RSSI
You can look for key CBAdvertisementDataLocalNameKey.
If you do not see the name, you can make changes in your firmware to include a name in GATT characteristic .
You can use LightBlue app to verify once. This is a good app on app-store to test your BLE device.
Related
I'm trying to establish a connection between my PC running Ubuntu and my iPhone via Bluetooth automatically when it becomes available, after being manually paired beforehand. I've seen this to be possible with certain peripherals, mainly audio. For example, my phone will automatically connect to a Bluetooth speaker when it is turned on and Bluetooth is active on my phone; another example is my phone automatically connects to my car's radio system via Bluetooth when I turn the car on.
I'm not able to connect my phone to my PC without first initiating the connection from the smartphone's Bluetooth menu. I'm thinking that I could possibly write an application for the PC to attempt to connect to the device every few minutes or something, but it seems that the phone needs to be the device to initiate the connection.
The only information that I need for what I'm trying to do ultimately is that the devices can pair successfully. Essentially I'm trying to build a sort of proximity trigger between my phone and my PC without using Wi-Fi and GPS - I can't use these for some specific reasons.
Is there any way to make this happen?
Yes this should be doable as long as you use the Background Processing feature for iOS apps. In the example I'll give below, we'll have the PC be the peripheral and the phone be the central, but you can really have it working either way. You will need to do the following:-
First initial connection needs to be performed in the foreground (this is due to iOS's background limitations).
On the iOS side, you need an application that acts as a central that scans and connects to the remove device (check this example as a starting point).
Upon connection, you need to bond with the PC. Bonding is important as it will prevent you from having to do the pairing again in the future. However, pairing/bonding is managed by the iPhone's OS so you cannot write it in your application, so the workaround is to have an encrypted characteristic on the PC side that will force the iPhone to bond (this is covered later).
On the PC side, you need to have a BlueZ script that acts as a peripheral that is always advertising. You can do this using bluetoothctl (check the examples here and here).
Before you start advertising, you need to have a GATT server on the PC side (to do this, check this example).
When registering characteristics, ensure that one of them has the encrypt-read property (you can find a full list of the properties here).
Now when you attempt to read this characteristic from the iOS side, the two devices should bond (make sure that your PC is bondable which you can do this via these commands).
Once the devices are paired, your iOS app needs to be working in the background constantly scanning and attempting to connect to the same peripheral (have a look at this and this example).
You can find more useful information at the links below:-
Getting started with Bluetooth Low Energy
The Ultimate Guide to CoreBluetooth Development
How to manage Bluetooth devices on Linux using bluetoothctl
I use esp-idf v3.0 and esp32 chip.
My esp32 is a gatt server and I communicate with a specific android app which is the gatt client.
In our system, there is a need for me to save some info for previous remote devices which were disconnected for future connection. For this reason I need some ID of the remote device, and for that I used the android bd address, but after experiments and some info from google, I understood that the bd address from android is unstable since it doesn't show the actual physical address.
Thus, I want to use the name of the android device as an ID (of course we will make sure to set our android machines to have a unique name).
But I can't find in the docs any option for reading the remote device name.
I would like to know if there is any function or example code for reading the connected devices name.
The common solution is to pair the devices. When you do that, you get the IRK (identity resolving key) which can be used to see if a given Bluetooth device address is derived using that particular IRK.
I need to get the friendly device name from a ble sensor. I want to find the device and tell the user they are connected to "My Home Sensor" for example. I can find the device, but I don't know how to find that data.
In regular bluetooth, I believe I can use BLUETOOTH_DEVICE_INFO or winsock.
Is there a bluetooth low energy equivalent to bluetooth's BLUETOOTH_DEVICE_INFO?
If possible, could you please provide an example for how to get the information (i.e. device name)?
I'm using Windows 8.1, c++ and visual studio 2013. I've been referencing windows dev docs, but I haven't found anything useful yet.
Thanks!
Assuming that you are able to get connected with the GATT Server, when you parse the GAP profile of the device, you will find an attribute for Device Name under Generic Access Profile (GAP).
This is a list of all the standard GATT Services and their UUIDs. UUID for GAP is 0x1800.
You can look for the list of all the standard Characteristics and their UUIDs. For the Device Name Characteristic, it is 0x2A00.
This explains that the Device Name characteristic is a part of the GAP.
I have small question about HM-10 ble module and master role.
I tried 2 scenarios.
Android app as master and hm-10 as slave:
From android app I can connect to hm-10 and its characteristic .
Everything works OK.
I have problem with second scenario: HM-10 as master and my ble device (LEGO SBRICK) as slave.
What I've done:
AT+ROLE1 - Set up to Central
Mode AT+IMME1 - Start from RESET
AT+SHOW1 - Show discovered devices
AT+DISC? - Discover Devices
AT+CON connect
Now my question is:
SBRICK is listening for ble command on service X and characteristic Y.
How can I send data from my HM-10 to specific characteristic of my SBRICK device ?
I can not find AT command for that.
I hope I didn't miss something from ble specification.
Any help please...
I am afraid there isn't an AT command to set a specific characteristic value.
The HM10 is a serial-port emulation device - It has a BLE characteristic, which displays all serial data (except AT commands). You will likely be able to find the service and characteristics details in the documentation (although I had a quick look and couldn't see anything).
So, data written to the serial port should appear as the value of that characteristic. Data written to that characteristic should be delivered out of the TX serial port pin on the HM10 module.
If you want to interrogate the device to find out it's serial and characteristic values, try using a debugging app - I use Light Blue on iOS, which will show all services and characteristics present on a device and show their properties and details.
pfodApp now supports BLE devices including HM-10. The free pfodDesigner lets you create custom custom Android menus and then generate the Arduino code for your particular hardware.
pfodApp supports data logging and plotting also.
We have bought BLED112 to interface our target via BT.
An android app interacting with target via BT & USB (HID).
We have used some Bluetooth communication to write a program and send data to dongle.
Now can somebody here having any experince in converting that BT data to a HID signal.
Have anybody tried that?
Is there any BGScript code which we need to write to achieve that?
Please let me know if the thought is completely wrong.
Referring to a comment above which states,
We are writing an Android App which can send data to BLED112 over BLE interface or GATT. My question is how can I convert that data (basically a command) to an HID (key event), correct me if my understanding is wrong?
If I understand the use-case correctly, I think, in the initial stages of the development, you will need to use the BLE-GUI utility that BlueGiga provides.
With that utility you can see the communication between the BLED112 Dongle and the BLE112 Module. BLED112 shall be simulating what the android app would do?
First, you will need to know the GATT structure stored in BLED112 to write to or read from the BLED112.
Secondly, the way BLE112 works is an event-based implementation. Going through the API reference document for BLE112 shall help you understand the events generation conditions and codes that are generated modified when a characteristic value is updated by the android application, or read by android application. You get events for connection, disconnection, read from, write to, notification enabled for, indication enabled for, etc.
On the BLE112 side, depending upon what service and what characteristics in that service is going to be used for data transfer between Client (Android App) and Server (BLE112), you need to write suitable implementation in event callback handlers.
There is a standard service called Human Interface Device which has a reserved UUID: 0x1812.
Once you configure your BLE112 as a HID over GATT device, your android app shall see a service with UUID: 0x1812. Parse the service descriptor and get the characteristics bundled up into the service. You can read from or write to that service depending upon access parameters set in gatt.xml
As an example, say, if it is a Keyboard, you can send the scancode for (make and break) of the key depending upon what key is pressed. How to get a scancode is out of the scope of this question anyway, and sadly I had worked on PS2 keyboards, so I don't really know how to get the scancode from a USB keyboard.
So, you have the scancode for the key pressed, and you know the characteristics to write that into. Write it, the application should enable the Notifications for that characteristics, so that it is notified whenever the key is pressed and value is written into the characteristics. To let application enable notifications or indications for the characteristics, study the developer guide that talks about how to write a gatt.xml for Bluegiga-based BLE devices. I'll give you a hint: in xml, in the characteristics configuration you have to write notify="true".
About parsing of the service and characteristics in Android, Unfortunately I am not an android developer, but an embedded developer, I know how the BLE112 module part is to be implemented, while I have no insight of how android parses the data. But, there are plenty of question and discussions about it online, which you might understand better than me since you have an android background.