Communications library
From WikIRI
back to the list of repositories
Contents[hide] |
Description
This set of drivers for standard communication devices. This library offers a generic communication device which can be used to create drivers for new communication devices easily: it is only necessary to implement the low level, operating system dependent functions, all the other features are already implemented.
The main features of all communication devices are:
- Data is automatically received and stored into a data FIFO by an internal thread.
- An event is generated whenever there is new data into this FIFO. Read operations are non-blocking.
- An event is generated when an unexpected error happen.
- Only a few functions have to be implemented to generate a new driver.
The communication devices currently supported by this library include:
- serial port: This drivers provides a simple and easy to use yet complete interface to a standard computer serial port. This driver allows the user to open any available serial port, configure it as needed and send and receive data to and from it. Some USB devices can also use this driver (those that appear as a virtual COM port).
- ftdi driver: This driver is intended to be used to interface with devices with any of the following FTDI chips:
- FT2232H
- FT4232H
- FT232R
- FT245R
- FT2232
- FT232B
- FT245B
- FT8U232AM
- FT8U245AM
This driver can also be used with USB devices that appear as virtual serial ports in the host computer. In this case it is also possible to use the serial port driver
- sockets: This driver provide an implementation of server and client TCP sockets in Linux. UDP connections are not yet supported. The server side can handle as many connections as needed, providing notifications for the following event for each of the connections:
- new connection
- disconnection
- reception of new data
Both the client and server can be used with other implementations of the POSIX sockets.
Dependencies
- cmake a cross-platform build system.
- doxygen and graphviz to generate the documentation.
- libusb-dev for libftd2xx. This package can be installed using synaptic in Ubuntu distributions. The software has been tested with version 0.1.12-8 of the library.
- libftd2xx for communication with FTDI chips. Note: Follow the instructions provided in the FAQ section of this page to install this library. The software has been tested with version 0.4.16 of the library.
- Utilities_library Basic tools used by the driver.
Repository
Browse source code at
https://haydn.upc.es/labrobotica/pub/applications/communications
To download this repository execute the following command (developers only):
svn checkout https://haydn.upc.es/labrobotica/applications/communications
An anonymous access is also available:
svn checkout https://haydn.upc.es/labrobotica/pub/applications/communications
FAQ
Q: How to install the libftd2xx.so library?
A: The Instructions provided by the manufacturer are a good point to start, but they are incomplete. For completeness, all the necessary steps are listed below:
- Download and extract the .tar.gz file into a temporal folder (for example ~/temp/)
- Copy the shared library file (libftd2xx.so.0.4.16) into the /usr/local/lib folder. This action requires root privileges:
> sudo cp libftd2xx.so.0.4.16 /usr/local/lib
- It is necessary to create two soft links to this library in order to work properly. From the /usr/local/lib folder and as root, execute the following commands:
> cd /usr/local/lib > sudo ln -s libftd2xx.so.0.4.16 libftd2xx.so.0 > sudo ln -s libftd2xx.so.0 libftd2xx.so
- It is also necessary to create a soft link to this library into the /usr/lib folder. Again, as root, from the /usr/lib folder, execute the following command:
> cd /usr/lib > sudo ln -s /usr/local/lib/libftd2xx.so.0.4.16 libftd2xx.so
- Next, copy all the header files from the temporal folder where the library has been extracted into the /usr/local/include folder. The files that need to be copied are ftd2xx.h and WinTypes.h. This action also requires root privileges:
> cd ~/temp > cp *.h /usr/local/include
- In kernels previous to the 2.6.31 it is necessary to modify the fstab file to complete the installation. For the instructions for newer kernels, see the next answer in this section. As root, edit the fstab file in the /etc folder and add the following line at the end:
none /proc/bus/usb usbfs defaults,devmode=0666 0 0
- Finally, remount all the devices in the ftsab file executing the following command as root:
> sudo mount -a
If this last command returns an error, follow the instructions in the following answer.
Q: How to use the FTDI driver without root privileges in kernels 2.6.31 and newer?
A: Ubuntu distributions with kernels starting from 2.6.31 no longer use mount the usb devices on /proc/bus/usb, and also, some distributions no longer support the usbfs file system. If so, the following error will appear when following the manufacturer's instructions:
mount: mount point /proc/bus/usb does not exist
In this case, follow the following steps:
- Follow the manufacturer's instructions up to the point of modifying the /etc/fstab file.
- Instead of modifying the /etc/fstab file, it is necessary to include a new rule in the udev server. To do that, as root, create a new file in the /etc/udev/rules folder:
cd /etc/udev/rules.d
sudo vim 99-ftdi.rules
(both the priority and the name can be changed)
- Copy the following line into the previous file:
SUBSYSTEM=="usb|usb_device", ATTRS{idVendor}=="0403", ATTRS{idProduct}=="6001", GROUP="dialout"
- Re-start the udev service to take into account the changes:
sudo /etc/init.d/udev restart
- Other FTDI devices have different product id, so it will be necessary to include a rule for each of them. The standard product id's are: 6001, 6010 and 6006.
Q: I would like to use IRI style in documentation:
A: Follow the intstructions in [[../../../../index.php/Iri_doc_folder|wikiri.upc.es/index.php/Iri_doc_folder]]
