Hauppauge DEC2540-T USB

DEC2540-T USB

A DVB-T USB 1.1 device manufactured by TechnoTrend and resold by Hauppauge.

It is supported under Linux.

Overview/Features

The DEC2540-T is a digital receiver set-top box that it is equipped with an USB port, allowing it to be used either as a PC peripheral or as a standalone STB (i.e. used without a PC). It is similar to the DEC2000-T but comes equipped with a Conax(?) decrypt card slot. Decryption is not supported under GNU/Linux. The device is only sold in the Netherlands.

The device's TV-Out can't be used for PC output.

The device can only deliver a partial/modified TS stream to userspace: due to the limited bus bandwidth provided by USB 1.1, of approximately 12Mbps, only selected PIDs can be transferred over USB to the host system. Consequently, some high bandwidth transponders won't work, and HDTV reception is not possible.

{Q. Does it use a Texas Instruments DSP that remultiplexes the stream into a TechnoTrend-proprietary USB packet 

format and sends it as Isochronous USB Stream over the bus ? (as in the case of the Hauppauge WinTV-NOVA-T USB) ??  Sounds like it does.}

One can watch digital TV with this device using xine, or alternatively record the incoming stream via cat'ting /dev/dvb. It will not work with VDR as a primary device because it does not have a hardware MPEG-2 decoder.

{huh? isn't this more a case of a VDR limitation, as it appears that device does indeed feature an onboard decoder ?} 

However, it can be used in VDR as a soft-device, streaming or xine or as secondary device.

• Playback and channel changing (via the playlist) is possible with gxine.
  • Set up the channels with scan (e.g. scan -o zap /usr/share/doc/dvb-utils/examples/scan/<country>-<region> > ~/.xine/channels.conf)
• You can record programs with

tzap "Channel id" -r & cat /dev/dvb/adapter0/dvr0 > "Programme.mpeg" &

Components Used

DEC-specific

• frontend ... NXP TDA10045 demodulator ?
• has an onboard hardware video+audio decoder ... AV711x MPEG-2 Decoder ?
• usb interface (Texas Instruments ?)

Identification

USB device id: 0b48:1009

Making it work

Firmware

If you have the kernel sources installed, or have installed the dvb-apps, use the following command:

get_dvb_firmware dec2540t

Copy the dvb-ttusb-dec-2540t.fw file downloaded by the above step into the /lib/firmware directory.

Drivers

The device's internal components are hidden behind the USB interface.

The following drivers are needed for this device:

 - ttusbdecfe.ko
 - ttusb_dec.ko

Also See

• Hauppauge DEC2000-T USB, a similar model
• the ttusb-dec.txt file found in the kernel sources (i.e /usr/src/linux'/Documentation/dvb/) for some misc. info

External Links

• Hauppauge product page
• A users report