Bluetooth Hub advice - bluetooth

I am considering automating the heating in my home via electronic radiator valves with Bluetooth. There will be 19 such valves. I therefore need several bluetooth devices (I am calling them hubs) which will interface to these 19 radiator valves, and allow me to communicate with them from a central PC. The PC will not be within Bluetooth distance of some of the radiators, so I need a device that can be connected to my ethernet LAN, and can then connect to each bluetooth radiator valve within reach and allow me to communicate with it from software on my central PC. I will need several of these devices. Questions:
Is what I'm suggesting technically possible?
Does a "bluetooth hub" like I'm suggesting exist? Please suggest any candidates that might do the job. Since I have to buy several of these I will be motivated by price to some extent. But also I don't want the hub to get in the way of communication between the radiators and the central host.
Any other helpful suggestions.
Thank you - Rowan

If you search the internet for the term "Bluetooth Gateway" you will probably find more solutions nearer to what you are looking for. A cost effective way of doing this would be using a Raspberry Pi Zero W (or WH). I am sure a ESP32 would be another good candidate.
I suspect your radiator values are Bluetooth Low Energy (BLE) so that is the way to build the gateway.
Looking into the future, this type of application might be done with Bluetooth Mesh

Related

Is there way to detect a certain phone from a few feet away

I am trying to build a system with a raspberry pi that allows clients access into a building depending on their membership status. Right now, it uses QR codes, but I want to know if it is possible to add a feature where it uses some technology like NFC or RFID or Bluetooth to detect their phone or RFID card from at least a foot away and confirm they have a membership.
Someone told me I could use RFID, but I am only aware of that being used in short-distance applications, like a card on a hotel door. I am not sure about Bluetooth either, because the phone would have to connect to the pi first, right? Maybe there is something I don't know about. So please offer any suggestions. Thanks
I think bluetooth does good work for tracking user. Since it's the best to handle large distances than NFC and RFID these two technologies are used for low range scenarios, check this link.
In addition, you can check distance(using Proximity and RSSI) and membership status as well. but you need to know how to handle bluetooth connectivity with raspberry pi check this link. as well create an app on that mobile phone to use Bluetooth (depending which OS you're using for Android, iOS).
Regards,

Is it possible to scan a bluetooth device to find it's capabilities

I am looking for a way to scan a device I own and discover "what it can do".
In other words, I'd like to know if a device is able to describe the way you have to communicate with it in order to build some application around it.
In my case it is a simple Christmas light that I'd like to play with but this could be used in different situations.
For classic bluetooth (BR/EDR):
When scanning for bluetooth devices (Inquiry), the bluetooth device will send an inquiry response (if it wants to be discovered) and maybe also an extended inquiry response (EIR). This EIR may already contain a list of services, the devices supports. This is a very fast way to get a picture of a remote device.
Moreover, the service discovery protocol (SDP) gives more information on a device. This takes some more steps. In SDP two devices can exchange their capabilites in kind of ping pong process.
For BLE:
After connecting a BLE device usually a service discovery takes place. The BLE peripheral (e.g. headset or a light) reports its capabilities to the central (e.g. smart phone). Some of these services have predefines functionalities. Additionally, it is free to the manufacturer to add custom services.

Is there a way to connect to iBeacon while my Bluetooth device is invisible?

I'm researching iBeacons. Can I connect to iBeacons while my Bluetooth is invisible (to be protected from hacks)?
I don't have beacons to test myself and can't find any clear explanation online.
iBeacons connect to mobile phones using Bluetooth, so it is essential to have that turned on. You also need to have installed an app with iBeacon support in order to receive communication from them.
If you'd wish to use a solution that does not utilize Bluetooth, you could try out IndoorAtlas. It's an indoor navigation technology based on Earth's geomagnetic fields. It's also completely hardware-free solution, just requires you to collect fingerprints in the area you are going to use for your project.
Three points:
iBeacon technology does not rely on a bluetooth connection to your phone. Beacons are one way transmitters. They do not listen to or otherwise receive any info from your device. Beacon technology following this model is inherently privacy friendly.
Mobile devices cannot detect Bluetooth beacons with the Bluetooth radio turned off. Sorry, it is just not possible.
Properly built beacon apps will not expose your mobile device's Bluetooth info because they are receive only. Of course, other apps on your phone might use bluetooth for other purposes, so your best bet is to audit apps using bluetooth and remove any that are not doing what you want.
I just bought some beacons and tested that, The answer is YES. it is possible to read beacons mac addresses while using the phone's Bluetooth connection as invisible. Using this you will get access to your beacon in any open place without getting hacked through Bluetooth.
Thanks all for your answers.

Redesigning Ti SensorTag

This is my first question in Stackoverflow :)
I'm trying to make few modifications to the Ti Sensortag but I have few questions please:
1- is it possible to make the sensortags communicate with each-other without a gateway?
(lets Say I put Sensor1 in bedroom 1 and sensor 2 in bedroom 2 can I make them exchange readings without the need for a gateway?)
2- can I install a micro USB over the interface connector to be able to use a portable battery pack? (photo of the interface connector)
thanks
You'll get better more in depth responses on the TI support forums as Ifor has said.
However, I can tell you the answer to #1... Regular bluetooth allows for things like piconets, but Low Energy does not. With LE you have a client/server (master/slave) connection between two devices only. It may be possible to modify the firmware on the sensortags to allow them to make connections to other sensortags, but then they'd have to give up whatever connection they currently had to do so. The master devices can connect to multiple slave devices, but the slave device can only be connected to one master.
As the sensortags are currently designed, I think they only work as a slave (server) device.
Press releases say that the new 4.1 spec allows for a single BLE device to act in both roles--central and peripheral eliminating the need for a gateway. A 4.1 update is, in theory, possible with 4.0 radio hardware like the SensorTag has. I personally haven't seen an example of this however and SensorTag processing resources may be a limiting factor to a dual role.
The Battery Pack connector breaks out VDD_EXT and GND and the SensorTag hardware schematic is available. Analysis by a hardware design engineer should be able to determine the suitability of a USB source powering option.
http://processors.wiki.ti.com/index.php/SensorTag_User_Guide

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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