Re: LZ: RT-Link: Has anybody gotten it to work?


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Re: LZ: RT-Link: Has anybody gotten it to work?



At 09:39 AM 10/15/96 -0600, C Kuethe wrote:
>On Tue, 15 Oct 1996, Mel Tsai wrote:
>> 
>> Actually, HP designed it that way on purpose.  That way you can't send
>> answers to a math test across the room!
>> 
I know a few engineers who use to cheat on tests (not just math), in just
this way.  They will transmit across the room.


>> Like you said, sending data will be prone to a host of errors.  I
>> doubt you'll be able to use the regular TI-85 link program to send
>> data (unless it's a very short distance).  Some sort of custom zshell
>> send/receive program will have to be written.
>
Yes, that is what's needed.  I'm working on an IR link,  but I need help
with the programming.


We need two peices of software to make this work, 1) A link program for the
pc that uses standard RS-232 tx/rx lines;  2)A link program on the calc that
uses one line as both tx/rx, or uses both lines as one tx and the other rx.   


The problem that the calc runs into, when we try to connect any asynchronous
device (RT-,Ir-, or modem), is that the calc uses the second line of the
link port as some sort of clock line.  Therefore,  the calc acts like a
synchonous device.


I've already begun working on the hardware side.  I am looking into two
different Ir transceiver devices, one is programable, the other is not.  The
first could be programmed as a TV remote or to act as any Ir type device.
This device, however, requires cofiguration code to be transfered to the
chip before it will operate.  The other chip is an all in-one device; the
tx/rx Ir LEDs are built in.  It communicates in the Ir-DATA standard mode (1
in, 1 out).  Both devices are half duplex.  Depending the LEDs selected, the
range could stretch out to 35-50 ft.  Both devices are small enough to be
mounted inside the calc case and run off the calcs batteries.


Would anyone one like to help with this project?


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