[comp.sys.atari.8bit] X-10 controller

lazear@GATEWAY.MITRE.ORG (07/31/87)

I need help with interfacing my 800 to an X-10 controller.

I have bought the X-10 computer interface (from DAK for $20) that, like
the older BSR, controls lamps and appliances by sending signals over
household wiring.  Once I got the cabling straight (add Pin 1 ground),
I could receive characters from the interface, but they were not the
correct ones (altho the quantity was right).

The controller has the feature that when you press a button to turn on/off
a lamp, the controller sends a message to the computer (to advise the
computer what just happened manually).  I am trying to read that message
through my 850 interface (R1:).  The message is supposed to start with
6 bytes of all-one-bits (i.e., 255), then 6 other bytes.  What I read
is a progression of 1,2,4,8,16,32,64,128 and a few more bytes that *could*
be correct.  

Has anyone else connected the X-10 controller and had any luck communicating?
I bought the IBM version cuz it had a generic RS232 interface.  I have looked
at the BASIC code that came with it and it seems straightforward and usable
as a model for my code (also in BASIC).

I have set the 850 to Concurrent-I/O, 600 baud (what the X-10 says it needs),
no parity, no "light translation", 8-bits, 1 stop bit.  I have tried varying
the speed from 300 to 4800, resulting in a changed pattern (and byte count),
but no recognizable data.  

The power of 2 progression in the leading bytes vs. the 1-bits I am expecting
seems an odd coincidence and I am trying to figure out why that occurred.  It
seems to me that if I can resolve why that happens, I can fix the rest.
If you're still reading, I'd appreciate any help.

	Walt Lazear
PS - I have another problem trying to use GET to obtain a character, when
ALL values (0-255) are legal input.  I've seen the old trick of putting 255
into the input register and waiting till it changes.  Any ideas?