FTDI on OS X (Snow Leopard)


New member

I'm having trouble getting the FTDI USB interface to work under Snow Leopard. I downloaded the FTDI drivers from their website, and modified Info.plist with the PID and VID for CFA910. When the device is connected, I get a new /dev/tty* entry -- as I should.

However, connecting to it via 'screen' or even Cool Term I can't send or receive anything. I've verified that the app is using 115200 8N1.

I've done some research online and it seems that other people have had issues with getting FTDI VCP drivers to work under Snow Leopard with other devices. Is there a header for the UART connected to /dev/ttyS0 to connect my own RS232 to Serial and effectively take the FTDI chip out of the equation? Alternatively how do I enable /dev/ttyS1 (which is already connected to RS-232 DB9)? There is no setserial in the Angstrom distro.

Looking for additional LCD resources? Check out our LCD blog for the latest developments in LCD technology.

CF Support

Using a different console

Additionally, if you have enabled one of the other serial ports and you wish to use it as the main console. you can append the console parameter to the bootargs.

You can see the full set of console options in the kernel parameter documentation in Documentation/kernel-parameters.txt

CF Support



We have a fix for the FTDI console port. The FTDI EEPROM need to be programmed differently for it to work properly on other OSes than Linux.

We have a Linux utility that can fix it if you would like to do it yourself. If not we can fix it here if you would like.

Thank you.


New member
Fix availability...

Is the Linux utility available for general consumption? I can work happily using a Linux VM, but i'd prefer to do my work via OSX.

CF Support


We have a fix for the FTDI USB Serial Port working incorrectly on OS X and Windows. The EEPROM in the FTDI chip needs to be reprogrammed with a Linux application to fix it. Attached is a tar.gz with the application.

Ensure you have followed the instructions for setting up the FTDI driver under Linux. See:

Extract the usb_test program from the attached tar.gz.

Plug the debug board's console port into the Linux host computer.

On the Linux host computer run usb_test like so to program the FTDI chip:
sudo ./usb_test 10032 1037CFA10032xxxxxx /dev/ttyUSBxx
Replace 1037CFA10032xxxxxx with the serial number from the back of the debug board. Replace /dev/ttyUSBxx with the device created when the console port is plugged into the host.

The output for that should look like this:
rje@rje-pc:~$ sudo ./usb_test 10032 1037CFA10032000058 /dev/ttyUSB15
Linux USB program and test
Copyright (c) 2003-2010 Crystalfontz America, Inc.

4 = argc
m_type == 6
initialized ftdi part
-3 = returned
2 = eeprom.product_id
programmed module connected
found unprogrammed module
1037CFA10032000058 = serial_string
6 = returned from eeprom build
Disconnect board.
Waiting for module to be disconnected...
If you have questions or comments please post them.