Hi. I'm using a TS7250.
I've built a display using large 7-segment display, hanging off a 64-bit shift
register. My
program sends data to the display using one DIO for data and another for clock.
This works fine until the cable to the display is more than about a meter in
length, then it
gets clocking errors. It doesn't matter how much delay I put in between
setting the data
bit and then the clock bit, there are glitches.
What's the best way of extending the distance to about 10 or 20 metres? I can
think of
loads of ways of doing it, but I'm interested to see if anybody can suggest a
cheap and
simple way.
The display uses 5V TTL - 74LS series.
Options I am considering:
* Some sort of driver at the 7250 end - but this will require power.
* Capacitors across the DIO lines?
* Using 2 DIO pins opposite in phase to make a differential driver - but will
this still be
prone to glitches?
* Twisted pair - but I'll still get crosstalk between clock and data?
* Serial port - with a UART at the far end - most complex solution.
Thoughts, anyone?
Martin
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