Is it possible to program a BT beacon to advertise a sequence of different Eddystone-URL/UID's in sequence? I imagine I could from something like a Raspberry Pi3 with a BT adapter, but I was wondering about something like an actual beacon.
Yes, this is possible. This technique is called "interleaving", and it is possible to do with both software beacons and hardware beacons.
Eddystone actually relies on this technique in order to match its multiple frames. When a receiver sees an Eddystone-TLM frame coming from the same device as Eddystone-URL or Eddystone-UID, it knows that the telemetry is for that beacon frame.
Using the same technique, it is possible to send out multiple URL or UID frames from the same device using different identifiers for each frame. Some commercial manufacturers such as Radius Networks support doing this in some of their products.
I dont think so. Im pretty sure you would need to have some smart device nearby that is running a program that is periodically changing the UIDs. The micro-controllers that power these beacons are pretty bare bones and are really optimized for transmitting bluetooth signals.
Here's how to do it.
EddyStone supports four types of payloads/frame-formats i.e, UID, URL, TLM, and EID.
Eddystone UID/EID are the frame-formats to use for this purpose.
As far as using the 'NordicSemiconductor NRF line' of beacons just make sure that these are fully Eddystone compliant i.e, support the EID frame-format.
Freely available Google Beacon Cloud platform is great for trying this out (called 'registering and provisioning your beacon').
It can be implemented w/o building or requiring any custom app at the client end.
On the client-side.
Use 'Google Nearby Notifications' & 'Google Nearby Messages'
On the server/cloud-side.
Google Proximity API for 'registering and provisioning your beacon'
Use 'Google Nearby Messages' API
Good luck with your project .
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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,
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.
I have a couple of questions concerning BLE beacons:
1) Are beacons based on nRF51822 chip the best solution? Or are there any other chips better than nRF51822? I want to take up BLE beacon development and struggling to find the right hardware for these needs. As a novice developer I want the beacon to be as cheap as possible in order not to waste money in case of a failure.
2) Is it possible to buy pure Eddystone beacon (not iBeacon)? The reason for choosing Eddystone is that Eddystone is capable of broadcasting URLs that are essential for me.
The second question stems from my failed attempts to find a pure Eddystone beacon on Chinese electronics sites like alibaba.com or aliexpress.com where the only firmware available is iBeacon. But iBeacon is not an option because it can't broadcast URL the way Eddystone does.
Apart from the above questions It would be great if someone wrote a quick guide for taking up BLE development with Eddystone and covered basic topics like: chip to use, beacon model, best website to buy beacons at, etc.
Thanks in advance,
Pavel
1) I've worked with Estimote beacons and Chinese beacons from Amazon and in my opinion, they do not differ in terms of accuracy too much. Especially for prototyping, I'd buy cheaper ones to test if your use case can be satisfied with BLE beacons. If it is too inaccurate with Chinese beacons, chances are that it won't work with more expensive ones either.
2) Why do you need the URL broadcast? If the app is going to use the url, it would have to be connected to the internet. Therefore, you can just query the beacon's IDs to a web service to get back an URL and use that. Personally, I think this is a better approach as you can configure the web service from anywhere to change the url for beacons where as if you want to change the URL of the Eddystone, you have to go to the beacon to configure it.
The nRF51822 is a common implementation, is flexible, well understood and can be very inexpensive. Be aware though that development costs, add on circuitry for power and/or peripherals, and packaging can easily eclipse the Bluetooth chip when you get to production cost savings.
If you want to buy an off the shelf beacon, most models supporting Eddystone also support iBeacon, simply because supporting both adds no additional hardware cost. Newer Radius Networks and Estimote beacons all support both. And, yes, cheaper generic Chinese suppliers often have bulk manufactured inventory from before Eddystone existed at only support iBeacon.
I'm building an application where a mobile phone with an accelerometer is used to control an app on a computer in a similar way you would use a mouse. So I need to send the movement from the phone to the computer over some wireless protocol. I am thinking about using Bluetooth but I am not sure what transfer delay to expect. Another possibility is using 802.11g. What do you think? What delay could I expect given that I don’t hit the bandwidth limit?
I worked with a group at Motorola who linked up an external accelerometer pack to a mobile phone using Bluetooth. This work supported a mobile games development class at USC's GamePipe Laboratory, and the speed was sufficient to control the mobile games developed by the students. You'll need to make sure your handset's Bluetooth stack has the correct profile enabled to allow data communication.
Another advantage of Bluetooth over 802.11g is that the frequency hopping Bluetooth uses will make it less vulnerable to interference by all the other 802.11 devices in the vicinity, which sit on one frequency.
I wouldn't expect the amount of data sent by an accelerometer would give Bluetooth any problems.
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.