I have a question regarding the max concurrent connections using bluetooth dongles. My system is based on 10 Raspberry Pi-es 2 and what I am trying to accomplish is to make a bluetooth low energy connection between them for some research project. My bluetooth dongles are: Cambridge Silicon Radio, Ltd Bluetooth Dongle (HCI mode). When I set up Raspberries for the bluetooth mode (Bluez, etc.) everything works fine and every raspberry can scan other raspberries (hcitool scan), but when I try ping other raspberries from one of them I only succeed to get response from 7 devices, where the rest of the devices report "Error: connect error: Too many links". I am wondering is this hardware related limitations or technology limitations, since I've read in a few articles that Bluetooth when making a piconet supports only 8 devices. Thanks in advance.
Related
I am using BLE v4.1 for my application where I am able to transfer 200 packets of length 20 bytes each from peripheral to central side.
I want to transfer data via BLE and play some music while the data is being transferred. The music file is available locally and will be played on earphones(can be wired or wireless BlueTooth earphones)
I am facing an issue of packet drops around 15-20% when I am playing audio through wireless earphones while data is being transferred via BLE and audio is played on phone Bluetooth earphones(tried on Android and iOS, both) simultaneously.
With wired earphones connected; there is no issue, I can transfer data via BLE and play audio smoothly without any issue but things are different with wireless Bluetooth earphones case. I tried it with different Android phones(Android 11, different manufacturers) and different BlueTooth earphones, the issue still exists.
What could be a cause for the same and how can I debug it?
Bluetooth and Bluetooth Low Energy has only one radio that can only do one thing at a time. The connection events are scheduled and cannot overlap. This means the throughput is shared among all connected devices. You will get a higher throughput per device with only one connection than with two connections.
You will have to experiment with connection interval and connection event length to find parameters that seems to work, and test with multiple Bluetooth controllers (phones), since all have different scheduling algorithms.
I just randomly found a Bluegiga BLED112 Bluetooth dongle and I tried to connect it to my Debian 10 laptop as a basic dongle for Bluetooth audio outs.
Unfortunately I wasn't able to solve all the issues I had, starting from the fact that the device is not fully listed once used lsusb and just a mere ID number - namely ID 2458:0001 - pops out and bluetooth or bluez helps weren't successful either.
This given, I tried to follow several of the guides you can find online, also by running available scripts, but again nothing worked.
So if it's possible, what should I do in order to run such a dongle for the basic use I mentioned above - i.e. just for connecting my stereo speakers to my computer?
Thanks
The BlueGiga BLED112 is not a regular Bluetooth USB dongle. It gives you a virtual com port that can be used to access an API that in turn acts as a BLE device.
It is ment to be used for development of IOT solutions.
Also it does not support Bluetooth Classic, it only supports Bluetooth Low Energy.
We are developing a product that communicate with iPhone use Apple External Accessory Protocol over iAP2 over Bluetooth low energe 4.0 but we find that we can not connect it through the BPA 100 bluetooth Analyzer wit ATS,so is the BPA 100 bluetooth a Analyzer support capture the Bluetooth low energe 4.0 datas? And this prodcut is it OK for MFi certification?
MFi license is not required for the BLE connection. Apple providing the way you can create own BLE device and define properties with BLE Device Identifier. This is a very easy process to make a connection with the BLE Device. You can multiple articles on the internet. How to make a connection with BLE Device with the help of the Core Bluetooth framework.
Yes, We have to buy an MFi license. I want to develop own accessory, Which we can connect with iOS device thru cable or Bluetooth over IAP2 protocol. IAP2 Make connection with iOS then to Application and we can share maximum supported data over Bluetooth or cable connection. But BLE we can exchange maximum limit data. BLE connection consumes less data energy and exchange limit data compare to IPA2.
As stated in the title, can both be ran simultaneously or is a second adapter required? For example, can one adapter run both BLE and BT classic at the same time - the BLE beacon broadcasts the MAC for opportunistic clients to connect to using RFCOMM.
If you are using a common CSR 4.0 Dongle or Ampac AP6212 (which purportedly uses the same Broadcom chip as the RPI3) then this is possible - they are "dual-stack".
Given this, the typical USB CSR chips have a hard limit of two connected RFCOMM clients and the Ampac, 8 or maybe more (tested for sure 8).
I have an android phone and I want it to communicate with 10 bluetooth modules, not simultaneously. I know that a master device can have 7 slaves for bluetooth connection. does it mean "pairing"?
The question is can I have my phone paired with 10 bluetooth devices? Then send them data seperately?
There is no set limit on the number of pairings possible for a device, except for any limitations made by the platform or bluetooth software stack (eg. limited storage).
does it mean "pairing"?
Bluetooth pairing and connecting are two separate operations.
When two Bluetooth devices pair, they will exchange Bluetooth addresses and encryption keys. If pairing is successful, it allows the devices to connect to each other at a later time.
When two bluetooth devices connect, the profiles are established (a2dp if a speaker, hfp if headset, etc), and they can communicate.
Sometimes there is confusion between pairing and connecting since most smartphones automatically connect after detecting a successful pairing.
Pairing is just done once, typically when you buy a Bluetooth product. Connection is done whenever you use the product.
The question is can I have my phone paired with 10 bluetooth devices?
Then send them data seperately?
As mentioned in the other answer, the maximum number of paired devices is platform dependent, it varies from product to product, but there is no set limit. The maximum number of connected devices (that you could send/receive data concurrently to) is 7 according to the Bluetooth specification.