Commands for Tx Power, Rx Power and RSSI - bluetooth

I have a looked far and wide, on the Bluez.org and Android developer forum, http://developer.android.com/resources/community-groups.html however have been unable to find the solution to what I am looking for.
Could someone please assist me to find out what are the commands to modify the Values of TX Power, and get the valued of Received Power (RX Power) and RSSI.
Much Appreciate it.
Daud

There are no standard or Public APIs to set the transmit power, typically the interface is given by the Bluetooth chip vendor via custom driver APIs to be able to set the maximum transmit power of a device.
For the RSSI you can get this value from device discovery - In android ACTION_FOUND intent has android.bluetooth.device.extra.RSSI which can contain RSSI for the remote device.

Related

Is there a way to advertise multiple beacons with BlueZ

I need to advertise 2 different sets of data, 31 bytes each. It doesn't look possible when I look at the core specification v4.0.
What I understand when looking a bit further, beacons can be advertised in 3 different channels : 37, 38, 39. LE Set Advertising Parameters Command makes it possible to choose a specific channel as well as all at once.
Is it possible to advertise different data in different channels ?
If it is not possible, the only solution I remain with is changing the advertisement data periodically using LE Set Advertising Data Command.
I would be glad to see a bit insight on performance, stability and power consumption.
Yes, your device can act as several BLE beacons as long as you periodically change the advertising payload. Your suggestion of using LE Set Advertising Data Command is my recommended approach and you don't need to change the advertising channel for this purpose.
In other words, what you can do on your device is set up a timer, and then as soon as the timer expires, you can switch to a different set of BLE data that is being advertised, which will create the affect of your device acting as multiple beacons.
Please see the following links which may be helpful to your question as well:-
Can BLE devices act as beacons
advertise custom service uuid with bluez 5.4x
Linux BlueZ custom Manufacturing Scan Response Data
Bluez BLE peripheral advertise custom characteristic with ADV data
I hope this helps.

Scan and identify bluetooth device

I've tried to post this question on Amateur Radio, but it was closed as off topic. I'm not sure this is the right place to post it as it's not purely software, but still.
Being a quasi-newbie in this game, I'm trying to identify a device which communicates on 2.4Ghz, a Bluetooth mouse talking to his dongle.
My goal is to identify the MAC address of the device and then reverse the protocol.
Knowing that my only documentation about it is his chipset and the associated datasheet :
Which are the basics step to follow to achieve this ?
What hardware and software tool should I use ?
Would dumping the dongle's firmware be a possible approach ? If yes why ?
So far I've tried three methods:
With a Ubertooth dogle and his Kismet plugin, I can see a lot of traffic, but I can't identify the correct device (the vendor is almost unknown). Also, I don't know why but Kismet doesn't let me do channel hopping, so I can only scan the channel 37 (most likely the device doesn't use this channel ?).
With a HackRF, but same problem, in all the noise I can't identify the device.
With a nRF52840 and a sniffing firmware, I can see a lot of traffic but can't identify the right dongle.

How do you get the actual name of a bluetooth low energy device?

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.

Reading Stick'n'Find BLE beacons

I am using a generic BLE plugin for PhoneGap when developing a BLE enabled application. It gives me beacons identification and RSSI, but reading more advanced attributes like battery status or TX power require specific communication with a beacon, which is manufacture dependant as far as I know. Does anybody of you know, how to read for example the battery status from Stick'n'Find BLE beacons. So far I have been able to discover, that it's necessary to connect to the beacon and after it a characteristic has to be read. But here, I am lost.
Marek
You must use a manufacturer SDK to do this. One user reported:
I reached out to the manufacture and they have an SDK (and sample app), you have to sign up for a free account to get access: https://bluvision.com/developer/beeks-beacons-sdk/ http://bluvision.com/developer/wp-content/uploads/sites/2/2014/09/Android-SDK.zip
See here: https://stackoverflow.com/a/26424648/1461050

Bluetooth UUID discovery

Does anyone know how a bluetooth device could pick up the discoverable devices' device IDs in range?
I am ideally looking for the simplest solution that involves the smallest implimentation of the bluetooth protocols.
A starting point would be good, I just wish to create a device that can store all the device ids of nearby bluetooth devices with minimal power consumption, preferably just using radio frequencies and not SDP and whatever else.
If you can't help me with this, please can you help me find good reading material for low level bluetooth (step by step) communication. The reading online is so high level that I cant work out what is actually sent, when.
Laalto nailed the answer from the Bluetooth spec/stack POV, but your question implies your looking for a stand-alone Bluetooth device - not just a laptop app scanning surrounding devices.
I can only speak for the BT chips that the company I work for manufactures (Cambridge Silicon Radio - CSR) but our chips can do that pretty much out of the box. Our chips have an on-board Virtual Machine sandbox that allows access to the firmware functions and Bluetooth stack of the chip. You can easily write a C code app to run in the virtual machine sandbox, on chip, that periodically scans for discoverable devices around, grab their ids and then download them when connected via USB or Serial, or maybe over BT when a device connects to the listener directly.
www.csr.com and www.csrsupport.com for chips, dev-kits, design references, etc.. etc...
You probably want a module with the extra HW (UARTs, USB etc...) as well as just the chip but you could implement this with something the size of a BlueTooth USB or probably smaller.
It would really help to know more about what your trying to achieve, why you want something that just scans the surrounding bluetooth devices and how big the device needs to be.
Sorry if this sounds like advertising. For balance: Broadcom make BT chips too!
The Bluetooth specs from http://www.bluetooth.org are a good starting place for low-level information. You need an account to access the specs, but you can create one for free.
Basically what you need to do is to go into Inquiry mode periodically and grab the response packets as they arrive. The more time you spend in Inquiry mode, the more likely you will discover devices in range: discoverable devices enter the Inquiry Scan mode only relatively rarely; it takes some time (10.24s at least with older Bluetooth versions) to scan all the possible frequencies in the Inquiry/Inquiry Scan frequency hopping schemes. And even then you can have suboptimal radio conditions.
For implementation I suggest you at least start with existing Bluetooth libraries such as BlueZ and do not attempt to create your own from scratch.

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