Here is a description to get a very cheap usb-serial interface based on a cellphone USB data cable which uses the Silicon Labs CP210x single-chip USB to UART bridge.
- Get a GSM-USB cable at eBay, marktplaats or whatever.
These cables often uses the Silicon Labs CP210x single-chip USB to UART bridge. - Look for the pinouts at http://pinouts.ru/ to identify the rs-232 TXD, RXD and GND signals.
For instance pinouts of the commonly available siemens datacable can be found here - This cable's usualy comes with a Windows driver, so after installing this driver Windows users can start using this serial port.
- For Mac OS X users it is slightly complicated, since most often no driver is provided with the cable. A few additional steps are needed.
- Look in the System Profiler (Aplications/Utilities) under Hardware/USB which type of interface is used for the cable:
usb data cable:
Version: 1.00 Bus Power (mA): 500 Speed: Up to 12 Mb/sec Manufacturer: Silicon Labs Product ID: 0x10c5 Serial Number: 0001 Vendor ID: 0x10ab - Here we see that this is indeed a Silicon Labs interface.
- Download the Virtual COM Port (VCP) driver from the Silicon Labs website (http://www.silabs.com/) The CP210x USB to UART Bridge Virtual COM Port (VCP) drivers are required for device operation as a Virtual COM Port to facilitate host communication with CP210x products.
- Install the driver by double clicking the SLAB_USBtoUART Installer
- Unfortunately the standard product and vendor ID in the driver are wrong. So you have to put the Product and vendor ID obtained from the System Profiler, as explained above into:
/System/Library/Extensions/SLAB_USBtoUART.kext/Contents/Info.plist - Open a terminal session
- type:
sudo kextload /System/Library/Extensions/SLAB_USBtoUART.kext - type:
touch /System/Library/Extensions - type:
ls -al /dev/tty.SLAB* - You should see the comport:
crw-rw-rw- 1 root wheel 9, 8 Oct 18 08:32 /dev/tty.SLAB_USBtoUART - Now you are ready to use your new serial port.
