Thursday, January 1, 2009
A compatible IRLP Interface Schematic
IRLP nodes generally must use official IRLP boards. Their reasoning is that headaches the IRLP volunteers would have to deal due to nodes using self-built cards that weren't behaving properly. It appears impossible to obtain an IRLP node number without an order form and payment. http://www.irlp.net/orderform.html The IRLP board is $105. They also suggest a $40 donation.
However maybe you are interested in messing with a Linux based repeater controller. Or are I need of a spare IRLP board for interim node setups and testing.
Kyle, K0KN has designed a schematic for people in these situations, to emulate the IRLP board. This is perfect for people in these situations, as seen here. Otherwise you might find some people willing to part with theirs on the IRLP mailing list.
The IRLP board has an on-board hardware MT8870 DTMF decoder. It feeds the decoded digits as a four bit word to the printer port on the PC. This helps to ensure you have dull duplex control at all times, no matter what the state of /dev/dsp.. The decoded digits hit the custom_decode file where you can script/define functions.
If you wish to use IRLP with a different open interface such as the VA3TO, WB2REM, G3VFP, G4CDY,...Rigblasters, MFJ, SignalLink, etc. (as many of these interfaces have schematics readily available.) The following two open projects have the code necessary to talk to interface IRLP to other hardware interfaces. The rtpdir bridge - to bridge EchoLink IRLP and Asterisk . And thelinkbox also supporting USB sound FOB interfaces.