I am not much experienced in bluetooth programming yet, but for my bachelor thesis I was asked to implement an interface for an blood presure monitor. In general this device is able to connect to other devices in order to share the data via bluetooth. It is also common licenced.
Now the Problem:
I have written an java program using bluecove to search for bluetooth devices. It works, but I can't find the device I want to. This blood presure monitor also has an button for activating pairing, which does not help either. Every time the device is getting new data (I measure my blood presure) it says on screen "transmitting data" so it trys to connect to an bluetooth device it knows.
Is there any special way I need to address it in order to get paired with it? So I would need to create an server waiting for this device to connect to, or is the general task impossible to handle?
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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.
I'm not sure how to correctly phrase this question, as I'm just starting to learn Bluetooth and its ways, but... imagine holding in an iPhone or Android phone in your hand in a large building with many rooms. You pair your device with a Bluetooth master device via an antenna in that room. Then once you move from room to room, your device communicates with other antennas throughout the building, but the device treats it as one pairing.
Is this at all possible? Was Bluetooth developed with this in mind at all?
Would this still work if the antennas were wireless? My idea is for devices to communicate with nodes via Bluetooth, and nodes interact with central base via wi-fi/local router.
Also, third random question: how does using BLE affect any of this?
Please tell me if I'm crazy! Thanks!
Bluetooth 4.0 BLE allows for a slave to connect to one master. 4.1 BLE allows for more than one connection, but I don't know if anything implements that yet.
Either way, there's no sort of "roaming" method pairing devices like with wifi access points with the same SSID. BLE however doesn't require pairing like regular Bluetooth, so you could just connect to a new access point each time you lose a connection.
You can also communicate via advertising packets from the "antenna" in each room. This would facilitate information being passed from those rooms to the phone, but not the other way around. This is basically how you communicate with BLE when you don't pair/connect devices and is how iBeacons work.
If you're writing the software yourself, and installing it in the building and on the phone, then I think it should be totally possible. Bluetooth devices can detect the distance and direction of other bluetooth devices. So if both devices are running software that is designed to, and grants permission to do so, it should be no-big-deal to programmatically auto-reconnect to the new nearest antenna whenever one becomes significantly closer than the one that your phone is currently connected to. As for software that already does this that you wouldn't have to develop from scratch yourself, no idea.
I am experimenting with Bluetooth Low-Energy (BLE) for the purpose of connecting a hardware device to an Android application. My goal is to send a recognizable piece of data to an Android phone.
I am using the keyfob from Texas Instrument's CC2541 Mini-development kit, and am programming it using the IAR Workbench (which I am learning on the fly). My issue is that I cannot figure out what code should be used to send data from the keyfob to the phone.
I understand that this is somewhat vague, but because of the non-disclosure policies of my company I cannot share the code that I am working with. Does anyone have any references to code for the IAR Workbench that will allow the CC2541 to send a piece of data? Right now, I prefer to use GATT if that helps.
Thanks, and please ask me more questions if I need to clarify anything.
Assuming you're working from a pre-existing service profile, there is a function for every service called ServiceName_SetParameter(). Calling that function will change the characteristic value. When the characteristic is read by the phone, it will receive this value. If the characteristic supports notifications, and your phone has registered for notifications on that characteristic, the new value will be transmitted whenever SetParameter is called.
You can implement any proprietary protcol to connect to and interact with your beacon device. It can assume other roles than just the beacon task. It can also listen to and respond to connection attempts thus expanding into a lot more than a regular beacon.
If you study the cc2541 close you realize it is a pretty advanced IO controller that offers a lot of IO signal possibilities. That way you could use the cc2541 as the heart of an IO control application where you measure and control equipment. Mobile apps can then easily connect to your beacon/IO Controller device and interact with the machinery it is hooked up to. As you see, it´s a remarkably versatile system on chip and a cool circuit to learn to program.
I am working on a project where I need to attach a sensor to the computer like laser sensor or an infrared sensor, to use in a foul line detection. Basically the idea is, if someone steps on the foul line, the laser or infrared will be blocked by person's foot, and the laser/infrared won't be received by the receiver, causing the sensor to send a signal to the computer.
The problem is, I don't know where to start something like this. How would I go about attaching a sensor to a normal computer (like a normal PC that we use)? If someone could direct me into a direction or has any inputs, that would be really appreciated. Thanks a lot!
You may want to look at Arduino (http://www.arduino.cc/). It is an open-source microcontroller that can be used along with a computer and is designed to be hooked up to various types of sensors. It also has an extremely helpful, active support community.
There are several approaches to the task of bringing the sensor signal into a PC (to take advantage of PC's computing power, good user interface, connectivity to the web).
Look for integrated sensors that have an interface for attaching to a PC (RS-232, USB, Ethernet). For example, you may find something useful by googling photodetector USB.
There are I/O (input/output) devices for PC. They have analog and digital inputs and outputs. Look up LabJack, National Instruments USB-6008 and dozen other types of commercial USB I/O boxes.
Connect sensors to a microcontroller (uC), then connect uC to the PC through a USB or RS-232 or Bluetooth (the list goes on). This involves more hardware. You'll need to write firmware for the microcontroller too.
Obviously, which approach to choose depends on your skills (or willingness to acquire new ones), timing, budget, team structure (if it's a team effort).
You could use a photo-transistor and a Yocto-Knob. The Yocto-knob is an USB device able to quickly detect resistivity changes, you just have to connect the photo-transistor to it. Here is an application which looks pretty similar to yours: they use a light barrier to detect and photograph a fast object:
http://www.yoctopuce.com/EN/article/how-to-drive-a-camera-shutter-automatically
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.