there are several tutorials on interfacing Microcontrollers with PC / Android Devices using Bluetooth modules.
http://i.stack.imgur.com/TEvk0.png
However, seeing this image at https://learn.sparkfun.com/tutorials/bluetooth-basics this question aroused in mind.
Yes it's possible to connect two MCU via bluetooth. You've got plenty of bluetooth module (HC-05, RN42) from different manufacturers. They're essentially drop-in replacement for RS232 cables and they work via a UART.
Related
I never used a raspberry pi before and I have a project part of which includes receiving data from a BLE blood pressure device over Bluetooth to a raspberry pi 3. I can pair the device to my raspberry but I have no idea what to do next. I need to be able to receive the measurements in my raspberry please help and thank you in advance.
PS: the device I'm trying to use is very similar to this one:
https://ibb.co/71365k5
Thanks for your answers, I have tried "Gatt" and "Gatttool" but the problem is after pairing the device is meant to send the measurement to its application on an android phone, without it I cannot read the blood measurement characteristic or it just does not exist.
Linux uses BlueZ as a default bluetooth stack. It exposes DBus APIs for implementing software using Bluetooth.
If you don't want to use this API directly, which can sometimes feel a bit low level you have many libraries that wrap it, such as https://github.com/getsenic/gatt-python that also comes with examples.
All other solutions requires replacing the Bluetooth stack on Linux and hence your other existing Bluetooth pairings to the system will stop working.
I just randomly found a Bluegiga BLED112 Bluetooth dongle and I tried to connect it to my Debian 10 laptop as a basic dongle for Bluetooth audio outs.
Unfortunately I wasn't able to solve all the issues I had, starting from the fact that the device is not fully listed once used lsusb and just a mere ID number - namely ID 2458:0001 - pops out and bluetooth or bluez helps weren't successful either.
This given, I tried to follow several of the guides you can find online, also by running available scripts, but again nothing worked.
So if it's possible, what should I do in order to run such a dongle for the basic use I mentioned above - i.e. just for connecting my stereo speakers to my computer?
Thanks
The BlueGiga BLED112 is not a regular Bluetooth USB dongle. It gives you a virtual com port that can be used to access an API that in turn acts as a BLE device.
It is ment to be used for development of IOT solutions.
Also it does not support Bluetooth Classic, it only supports Bluetooth Low Energy.
i am new to Linux and Bluetooth. i know that the standard implementation of the bluetooth protocol stack is bluez. I know that alsa is not supporting bluez anymore and if you want to use audio over bluetooth, you need pulseaudio. so pulseaudio should support HSP/HFP since version 6 and bluez 5.x. Know i was wondering if i can connect a usb-dongle to my hardwareboard (raspberryPi) there is a serial connection to the board. is that right? so the Dongle has the BT-STack and you can use alsa audio over USB like an USB HEadset?
i hope someone can help me.
The answering this vast addressable question is not that easy. I have few hints which will help you to narrow down.
BlueZ is user layer stack to communicate or use the functionality of Linux Kernel Bluetooth subsystem and provides helpers to developers.
USB Dongle itself doesn't have any stack and I don't really understand your question in that sense. To brief, USB Bluetooth Dongle is just the hardware device with Bluetooth functionalities. To make it functional, you need Linux Kernel Bluetooth system support enabled and either you can directly make use of "socket" system calls to pair,connect etc., or use BlueZ to develop applications with API's
BlueZ itself doesn't provide API's for developers, instead it makes use of the DBus to provide methods, properties and signals with vast range functionalities. Check here
If you interested in Audio Playback using Bluetooth, then you should register your media player and audio sink with BlueZ with according media DBus Interfaces.
To add, I am currently developing a framework library to wrap the DBus functionality provided by BlueZ for friendly development of applications. Check this repo and it is currently in initial development phase.
I wonder whether it is possible to emulate a specific bluetooth device like a Remote Controller for a TV or another device with my PC. I'd be okay with installing an additional hardware device for my computer (e. g. a BlueTooth PCIe card).
I imagined something like "recording" all single commands of my original remote controller using my Bluetooth card and afterwards use these recorded commands to turn on my TV for example.
Is something like this possible (with additional hardware maybe)?
Of course this is possible. Bluetooth is just a protocol and you can impliment it in your custom software to emulate all kinds of devices. If you need to emulate simple devices like keyboard or mouse, there are many ready solutions like this.
But if you have non standard device, there won't be any ready solutions and you will have to implement it yourself. What can help you:
If you have some kind of controller for PC and you want to emulate device with unknown protocol, you can use WireShark or other sniffer to understand what's going on.
There is an emulator called BT-Sim, but it is so poorly documented that I can't even guess what it does.
You can can take as example different android software like described in answers to this question.
You can check different program samples for PC like this.
For hardware you need only simple Bluetooth dongle. However, if you want to spy on some BLE (Bluetooth Low Energy) devices, you can buy hardware sniffer like this.
(At least in Windows 10) Microsoft Store has an application called "Bluetooth LE Explorer" which is able to simulate different kind of Bluetooth GATT profiles as a peripheral.
Is there a way to use one computer to send keystrokes to another by usb ?
What i'm looking to do is to capture the usb signal used by a keyboard (with USBTrace for example) and use it with PC-1 to send it to PC-2.
So that PC-2 reconize it as a regular keyboard input.
Some leads to do this would be very appreciated.
What you essentially need is a USB port on PC-1 that will act as a USB device for PC-2.
That is not possible for the vast majority of PC systems because USB is an asymmetric bus, with a host/device (or master/slave, if you wish) architecture. USB controllers (and their ports) on most PCs can only work in host mode and cannot simulate a device.
That is the reason that you cannot network computers through USB without a special cable with specialised electronics.
The only exception is if you somehow have a PC that supports the USB On-The-Go standard that allows for a USB port to act in both host and device mode. USB-OTG devices do exist, but they are usually embedded devices (smartphones etc). I don't know if there is a way to add a USB-OTG port to a commodity PC.
EDIT:
If you do not need a keyboard before the OS on PC-2 boots, you might be able to use a pair of USB Bluetooth dongles - one on each PC. You'd have to use specialised software on PC-1, but it is definitely possible - I've already seen a possible implementation on Linux, and I am reasonably certain that there must be one for Windows. You will also need Bluetooth HID drivers on PC-2, if they are not already installed.
On a different note, have you considered a purely software/network solution such as TightVNC?
There is a solution:
https://github.com/Flowm/etherkey
This uses a network connection from your computer to the raspi which is connected to a teensy (usb developer board) to send the key strokes.
This solution is not an out-of-the-box product. The required skill is similar to programming some other devices like arduino. But it's a complete and working setup.
The cheapest options are commercial microcontrollers (eg arduino platform, pic, etc) or ready built usb keyboard controllers (eg i-pac, arcade controllers,etc)
SEARCH THIS PROGRAM:
TWedge: Keyboard Wedge Software (RS232, Serial, TCP, Bluetooth)
then, MAKE YOUR OWN CONNECTION CABLE WITH:
(usb <-> rs232) + (NULL MODEM) + (rs232 <-> usb)
Connect 2 computer, write your own program to send signal to your (usb <-> rs232) unit, then you can control another computer under the help of TWedge.
The above mentionned https://github.com/Flowm/etherkey is one way. The keyboard is emulated from an rPi, but the principle can be used from PC to PC (or Mac to Whatever). The core answer to your question is to use an OTG-capable chip, and then you control this chip via a USB-serial adapter.
https://euer.krebsco.de/a-software-kvm-switch.html
uses a very similar method, using an Arduino instead of the Teensy.
The generic answer is: you need an OTG capable, or slave capable device: Arduino, Teensy, Pi 0 (either from Rapberry or Orange brands, both work; only the ZERO models are OTG capable), or, an rPi-A with heavy customisation (since it does not include USB hub, it can theoretically be converted into a slave; never found any public tutorial to do it), or any smartphone (Samsung, Nokia, HTC, Oukitel ... most smartphones are OTG capable). If you go for a Pi or a phone, then, you want to dig around USB Gadget. Cheaper solutions (Arduino/Teensy) need custom firmware.