Im running Qt on ubuntu. I want to write a simple program that recieves a line from android device(this device already has a program to connect and send info) over Bluetooth. How do i start a bluetooth server in QT? I tried to find examples, but all of them act like a client that looks for connection. My program should wait for connection and once it gets a connection, it waits for incoming messages and reads them.
The Bluetooth API provides connectivity between Bluetooth enabled devices.
You can find Bluetooth examples in Qt website here, also see some Bluetooth examples in Qt Creator examples.
Bluetooth chat example and Bluetooth file transfer example is works for you.
The Bluetooth chat example may be used with various Bluetooth terminal applications. For example you could compile the Qt BT chat example on your computer and connect to it from your cell phone running a Bluetooth Terminal application.
In order to do that all that is needed is to change the UUID values as described here and here. That is, in the chatserver.cpp file of the example one needs to change:
static const QLatin1String serviceUuid("e8e10f95-1a70-4b27-9ccf-02010264e9c8");
Becomes:
static const QLatin1String serviceUuid("00001101-0000-1000-8000-00805F9B34FB");
You may also want to do the same thing in the chat.cpp if you are planning on using the client mode as well (in this case make sure to change the reversed UUID also, as described in this bug).
Related
I have been trying to set the limit of pairing the Bluetooth device HC-05(interface by Arduino controller) with my smartphone.
I have tried making this solution work with AT command
AT+INQM=<Param>,<Param2>,<Param3>
Example: AT+INQM=1,9,48\r\n
But instead of converting AT commands using serial.h with embedded C, I am looking for any dedicated library which helps to work this kind solution in using Arduino.
Basically, with the help of Bluetooth device connect to Arduino Nano, I want to send the altimeter sensor data to my smartphone.
During the connection, HC-05 should be responding any one device at a time, if another smartphone tries to pair then the error will be shown.
Please share your advice on this.
Yes there are some libraries in arduino but these are only meant for connection and pairing and low energy connections. We don't have any dedicated library from where we can control the mode of operation of HC05 or any bluetooth module. like bypassing or accessing GAP and GATT services of bluetooth. However there is a way to flash HC-05. But we can only use it for updating the firmware of this device. This github repo is dedicated for this purpose . Hope it helps you
I bought one of these:
https://www.aliexpress.com/item/Smart-finder-Key-finder-Wireless-Bluetooth-Tracker-Anti-lost-alarm-Smart-Tag-Child-Bag-Pet-GPS/32806261079.html
As far as I can tell it is a BLE (Bluetooth Low Energy) location tag.
I downloaded the app for it onto my iphone, and the app instantly recognised it and connected to it. The iPhone app seems to know how far away the tag is - it has a little map of the local area and says how many feet away. I was able to set the device name via the app, but I'm not sure if that set it locally or on the tag itself. The iPhone app also has a "find" button - when you press it, the tag beeps.
So I want to know how I can program this thing myself. I want to be able to identify it when it is nearby, connect to it and make it beep. I've searched for quite a while but not come up with much.
I'm assuming (wrongly/rightly?) that there is some general standard or approach for talking to these BLE location devices and carrying out the basic functions with them - but what is that standard - where is the documentation?
Does anyone have any idea how to program these BLE location tag devices?
BLE devices typically communicate using GATT, either using standard GATT services, or custom ones. The command to make it beep is probably implemented using a custom GATT service.
For finding out the distance to the beacon, typically the RSSI is used. This is a measure of the received power. It needs to be compared to the output power at the emitter. Usually beacons will put their output power in advertisement data, so it can be used without connecting to them. Here since the app is also able to send commands to the beacon, chances are it keeps a connection to it and has a custom GATT protocol to retrieve the output power.
Here is what I would suggest:
Read up on BLE, especially advertising and GATT. For instance read this for advertising and this for GATT. The full BLE spec is available here but should be used for reference and not introduction
Sniff the communication between your device and your phone. You can see this other answer of mine to get started
Replicate the communication protocol in you own app. For that you'll need to use your target platform's BLE libraries. For instance for iOS it is CoreBluetooth
I need to create a Qt GUI that enables the user to select an option from a comboBox and on pressing a 'send' button, send some data to a STM32f072-Disco board via Serial Communication ( over a COM Port - COM11). I looked at the Qt blockig master, blocking slva eexamples but don't understand them very clearly. Any suggestions on how I can proceed ?
I've managed to make a Qt application with some help from sources on github.. The application is able to send & read data from the stm32 board. The stm32 dev board is configured as a CDC device.
The library provided # https://brosnanyuen.blogspot.in/2016/06/stm32-usb-cdc-vcp.html is useful for CDC communication as the stm32 middleware is slightly complex to use.
The git repor # https://github.com/WalkingFrog/Qt-SerialPort-Programming-Demo is a good start for beginners looking for a start.
I can share my code on any requets.
Not sure if to posted this on SO.
I'm looking at pretty simple BLE Device. It has a two LEDS (to simplify) that can be switched on or off.
While browsing the GATT profiles, i can't find which profile i should use. Most of them send something back (like a temerature) to the client (upon request).
I need the opposite: switch something on/off of the BLE decive (server). In my case, the client (a iPhone) would send a command to switch on/off LED-1 or LED -2.
What service profile i should use?
Thanks.
I'm using the nRF8001 development kit & nRF Studio for making the services.h
If the LED's are just to be turned on/off there probably isn't any specific profile that they belong to. You probably need to know the handle and write directly to the attribute some value that maps to on or off. Maybe you can figure it out by listing all attribute characteristics. (unfortunately I don't know how to do that specifically on the iPhone)
I noticed that you are using the nRF8001 development kit. So, first thing you need to check is whether the LEDs are connected to IO port of the micro-controller on the kit or directly connected to IO port on BLE chip.
If it connected to micro-controller on the kit then you need to program the kit to handle the received bluetooth data to control led. (It would have a high chance it is in this situation)
If it connected to BLE chip, it means you need to program the ble chip first.
Usually, useful GATT profiles are user specified. It means you need to define the profile yourself. And, I believe some part of the kit or the studio would allow you to do modifications to the profile.
There is only one default GATT profile you should use -- GAP which is to define the defaults like name of the ble device. The others usually are user self-defined profiles.
I want to implement bluetooth communication on my final bachelor project, but I'm having a lot of doubts.
One of the requisites of this project is to have a Java application that can talk to the micro via Bluetooth. After a lot of research, I've found one that I think it's very good with a SPP profile, but I still have a lot of questions about it:
All the bluetooth on a PC implements the SPP profile stack?
If you need to develop a Java application that runs on every PC that implements the SPP stack, how would you do it?
We started by trying to use BlueCove and JavaBluetooth.org API, the first one runs great but I don't know if it's just on my PC and the second one sends an error (Stack not initialized). Which one would you use, and why?
We decided to buy this bluetooth module, from Sparkfun, any comments for those of you who already use it?
Thanks
I used a similar product for my senior design project from Sparkfun (RN-41): http://www.sparkfun.com/products/10559
It worked right out of the box as a simple UART. This allowed my team and I to develop a simple C# application that used the .NET SerialPort class (System.IO.Ports) to communicate between an MSP430 and the PC application we were developing. If streaming data is all you care about, these Bluetooth modules work great. Java implements a similar SerialPort class for RS-232 communications. Don't forget that Bluetooth was developed to replace a serial cable.
I hope this answer helps! Good luck.
I personnally achieved to use the Sparkfun's bluesmirf devices to communicate with my own Java application (an Eclipse plug-in). I tested it successfully under Windows, MacOS & Linux based systems.
I used the RXTX Java library to connect to the corresponding serial port once the Bluetooth devices were paired. Under Linux I even achieved to configure rfcomm to automatically pair the Bluetooth devices on demand.
From my experiment I encountered some stability issues... Sometimes it simply fails to connect to the given port even if it exists or refuse to reconnect on it. Sometimes it hangs the whole system...
I never found any good solution to fix those issues that seems to be completely system dependent. I would be interested if any one achieved to use it properly...