I'm having trouble understanding the API to set up a l2cap (or RFCOMM) client/server running on OSX like I can with BlueZ on Linux.
On Linux, I simply open a socket, bind, listen & then accept for the server, & socket, bind, connect for the client (w/ the bind taking in the BT address of the device I want to use). Also, there's no pairing done.
I can't figure out how to configure my application to start listening for connections on a particular device (or if OSX only supports 1 BT adapater at a time, then how to listen for any incoming connections).
I also can't figure out how to configure my application to send to one BT device using a particular device (this is irrelevant if OSX only supports 1 at a time).
Also, does the OSX stack require pairing to have occured between 2 devices before it'll pass through l2cap?
Any language examples would be appreciated, although C/C++ would be preferred.
Thanks
In Mac OS X 10.5 there's an example (in /Developer/Examples/Bluetooth, titled RFCOMM_Open_SPP_Example) that shows connecting to and reading data from a bluetooth device (i've used it to read NMEA lines from a BT GPS receiver). See also: Leopard & Bluetooth RFCOMM channels
Unfortunately I can't find a copy of the example project anywhere.
It looks like the code samples have been replaced with: Developing Bluetooth Applications
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I am asked to connect my device to a server via a bluetooth connexion, such as an android tablet that gives an internet access via bluetooth.
The software on my device is entirely C, and the device runs a debian.
I know how to use regular network sockets, and how to use bluetooth sockets, which is practically the same.
but I have strictly no idea how I could use some sort of bluetooth gateway to access the internet, IE what if I want to write on a socket that's open with a distant server over the internet... through a bluetooth socket? As far as I'm concerned, the bluetooth sockets I open are strictly reserved to the machine I am in direct connexion with.
An application on the side of the android/ios device is apparently out of question.
Is this actually possible, and if yes, where should I look?
I am using the socket module in python to send commands to my raspberry pi to turn GPIO pins on and of.
I am switching to C, where I will use winsock.h and winsock2.h to create the server on my PC and sys/socket.h to create a client on the raspberry pi.
Is it possible to establish a connection between these two different libraries?
I only want to create a socket, bind, send and recv. No other operations.
I recommend you to check this documentation, there are some examples for a Windows Server / Client connection:
https://learn.microsoft.com/en-us/windows/win32/winsock/getting-started-with-winsock
For Linux you need to do some adaptations as you might know or you have already implemented, I did the same for 2 desktop applications to send data from a Linux PC (client) to a Windows PC (server). As mentioned in the comments it doesn't matter the devices while they are in the same network and follow the TCP/IP protocol.
I was able to do this even connected through a VPN. Unfortunatelly I can not share the code. But I developed this communication based on the documentation from the link above.
I hope it helps. Actually if you want to use Python in the raspberry Pi there is also a python built-in package that you could use: https://docs.python.org/3/library/socket.html
And you can use the code from the link above in Windows. It should be straighforward.
I want to use Bluetooth(4.0) on my board to transmit it's Name so any Mobile Application can see it's name and Mobile application initiates the pairing and connection with my Bluetooth.
I have seen some examples of Bluetooth(4.0) scanning nearby devices; For example:- It does scan for Bluetooth Mouser/Keyboard, but in this case Bluetooth(4.0) is in mode where it chooses the device it want to connect while I want it reverse so Any mobile application can see my Bluetooth and gets connect with it and does communication.
How can I put my Bluetooth(4.0) in such mode in Linux? Is there any C library using which I can put Bluetooth(4.0) is the mode where it goes in Bridge mode instead of scanning nearby devices?
You can set the name of your device like this:
hciconfig name "foo"
and check your name with:
hciconfig name
You also have to enable Low Energy advertising for your device to be found by others:
hciconfig leadv
You can configure your device to accept incoming connections like this (lm for link mode):
hciconfig lm MASTER,ACCEPT
This way the kernel will accept a connection, even if there are no listening sockets.
Considering you want to do actual communication, you would need to write a program, accepting the connection and sending/receiving data. Just putting your device in a mode where other devices can connect to it isn't really worth anything (because you can't communicate).
The basic principle is to open up an L2CAP socket, with the Channel ID of 4 (for Low Energy), then do standard bind/listen/accept. I suggest you look at the source code of Bluez and the examples.
I am trying to implement Bluetooth using "connect-blue-oem-spa-331" module using UART protocol and using MSP430 as base controller. I'm using Embedded C as a language of programming.
Everything just works fine until I reach to Serial Port Link Command "AT*ADCP". Every time I get response as ERROR. I have tried with both options by keeping ECHO ENABLED and ECHO DISABLED.
p_cmd = "AT*ADCP=XXXXXXXXXXXX,0,0,0\r";
this is my command. 'X' represents the Bluetooth confirm device address which I confirm when I execute DEVICE_INQUIRY command.
The module through which I am executing all these commands is always MASTER and will initiate pairing and communication process. As a safety I have kept it non-discoverable.
How can I implement the Serial Port Profile Link command without getting error when I confirm the bluetooth device using DEVICE_INQUIRY command.
I have been working with blue tooth for last 4 months. I had faced above issue in early days. And after running through documentation available for product I solved the issue. I thought to reply this question which I've asked.
I was using Connect Blue OEM-SPA-331i classic Bluetooth module in my project, and was using Serial Port Profile to implement Bluetooth commands.
When I inquire devices I get the list of Bluetooth Devices available and discoverable in the vicinity(mine was CLASS-I Device); and lists them as (48 bit MAC Address,Class of Device) i.e. ( 001234ab987f,786545) of the discovered Bluetooth Module.
When I'm trying to establish Serial Port Profile Link, it was required that I must write address of peer device to be connected over Serial Port Profile in Serial Port Adapter. The order of the commands should be
Inquire discoverable devices
Write the desired peer device address to Serial Port Adapter, remember it in power cycles.
Establish Profile Link.
This way I resolved my issue of link not getting established.
I'm trying to learn how to write C code that will read from the serial port in Linux. I've found what seems to be a good tutorial here.
I want to be able to test this code, so I think I need either a serial port, or a way to write to the serial port while the code from above is reading.
I'm running Ubuntu 10.04 as a virtual machine on my Mac using virtualbox. My idea was to set up a virtual serial connection and write from the host to the guest. Hopefully something as simple as cat "Hello World" > /tmp/fake_serial in a host terminal, and for that to be read by the program in the link above.
Is this possible? I've tried adding a serial port using virtual box and when I try to do the above command I get an error saying I can't write to a socket.
The second option I thought of was using something like minicom inside the guest OS, to connect to say /dev/ttyS1 and write messages for my code to read at the same time. Again, assuming that the baud rates and other settings are OK, would this be possible?
I don't have a lot of experience working with serial ports, so I'd appreciate any suggestions about the best way to do this. Thanks in advance.
So to get this working I just added another Ubuntu VM on VirtualBox, and connected the two together via a virtual serial port. My main, original VM, which I use for a lot of developing will be referred to as VM1. The new VM, with a small hardrive that will only be used for sending messages to VM1 will be called VM2. These are both Ubuntu 10.04 VMs.
In VirtualBox go to Settings for VM1, go to ports, and change the settings as follows:
Now go to VM2, and select settings, ports, then change as follows:
Now first you need to start VM1. When that's booted then boot VM2. Now you can open a terminal in VM1, and type screen /dev/ttyS0 38400 (you may need to run sudo apt-get install screen before this works). Then go to VM2, open a terminal, and type echo "Hello" > /dev/ttyS0.
You should see Hello appear in the terminal open in VM1. When you're done running screen press ctrl-a k to kill it, otherwise if you try to do other stuff with the serial port you may get an error message saying that the port is busy.
When I had to do some serial port testing from my real to virtual machine I ended up doing a "loop back" type testing. I took two USB-Serial converters and a RS232 F-F adaptor and connected my machine to itself. Then in VirtualBox under Settings->USB you can route one of the two USB-Serial converters to be "owned" by your VirtualBox.
Once you plug in the converters one will register with the Mac and one with the Ubuntu "computer" then you can do serial communication as normal between the two machines.
You may also be able to emulate a virtual serial port using a pty ("pseudo-teletype" device), but I'm not positive on that one since I believe the ability to do that was locked down in newer kernels.
I ran into a similar situation running a QNX guest using VirtualBox 5.0.10 on an Ubuntu 14.04 host.
My solution seems general enough to apply to the above-mentioned case.
I configured the guest VM in the same way that Kells1986 setup his VM1:
Under the "Serial Ports"/"Port1" tab:
check "Enable Serial Port"
set "Port Number" to "COM1"
set "IRQ" to "4"
set "I/O Port" to "0x3F8"
set "Port Mode" to "Host Pipe"
uncheck "Connect to existing pipe/socket"
set "Path/Address" to an accessible file-system path (e.g. "/home/safayet/vmSerialPipe")
According to the VirtualBox manual:
You can tell VirtualBox to connect the virtual serial port to a
software pipe on the host. ... On a Mac, Linux or Solaris host, a local domain socket is used ... On Linux there are various tools which can connect to a local domain socket or create one in server mode. The most flexible tool is socat and is available as part of many distributions.
A domain socket is an IPC mechanism on UNIX systems similar to a pipe.
I connected to the "pipe" end of the virtual serial port on the Ubuntu host using the socat command:
socat - UNIX-CONNECT:/home/safayet/vmSerialPipe