9 Nov
2014
9 Nov
'14
2:03 p.m.
On 11/07/2014 11:42 PM, tony duell wrote:
With no UART, I guess it bit-bangs the serial protocol
(I am surprised there's no
CDP1854 on the board). Pity. If there was a UART you could stick a 'scope on the
baud clock input and find out what bit rate to use.
Well, going by the doc which Francis posted, it expects a carriage-return
character to be sent by the controlling device at power-up, and it
automagically adjusts the baud rate. I'm a little skeptical about that
(because hard configuration of line parameters is typical with serial
hardware), but I don't know enough about RS232 comms to say how
plausible/reliable it is.
What the docs don't state is the other expected line parameters - data
bits, parity, stop bits, so I'm completely in the dark there.
Anyway, so far it doesn't work (and of course I'm not surprised), but I've
not done any diagnosis yet beyond simply reseating chips and checking the
PSU rail. The board does support a parallel input mode via keypad too, so
maybe I'll try that just to rule out the RS232 side of things.
cheers
Jules