🚀 go-pugleaf

Garry wrote:

> In article <19950324.195215.02@rhanna.demon.co.uk>,
>           adrian@rhanna.demon.co.uk (Adrian Kennard) wrote:
> 
> > So, My Archi is tied to an atomic clock (by radio) - and it never shows a
> > time adjust of other than 0 seconds when connecting to demon.
> [Small snip]
> 
> How about some technical details ?
> 

Ok, how technical? (I have MSF specs if anyone wants...)

I have an I/O podule, so I wired one of its spare input lines (not part of
the user port) to a single bit input that is connected to a DIY radio clock.
The clock came from Maplin I think. I wrote a module that gets the time code
from this and sets the clock before starting !Alarm. I run this (background)
at part of the hard disc boot. When !Alarm pops up I know the time is set
(couple of minutes after power up). This morning it (of course) popped up
with the correct summer time without any intervention from me.

The radio signal is sent from Rugby at 60KHz CW using a simple long/short
pulse of carrier each second to convey the correct local UK time and date
once per minute.

You could equally run such a system that uses some other input - perhaps RI
on the serial port (does anything else use that ?!?).

Unfortunately the Maplin clock is a pain to construct and position. It also
doesnt like being too near a computer. However there seem to be new
developments in the field of radio clocks....

You may have seen large radio clock (with clock face, etc) for something
like 100.00GBP. Well now it seems that someone has made some custom chips to
do it all..

You know the usual quartz "kitchen clock" type thing you can get from BHS..
With a small black clock module on the back that takes a 1.5V battery - well
you can now buy for something like 20.00GBP a clock module that is exactly
the same size that is in fact a full radio clock and quartz clock module. It
comes with hands and fits to just about any clock face (hand length
permitting).

I plan to put one on my wall and interface it with my computer. Internally
this thing has a small ferrite rod and small PCB with three chip-on-board
(black blobs). There are also some very convenient test points that
interface from the radio unit to the control unit. These provide the radio
signal pulse and a control line to turn on the radio signal. It seems that
the unit enables the radio periodically (every hour) and re-locks the time,
hence saving battery (which is supposed to last 18 months). It would be
possible to run three wires to the Archi - use an output port to enable the
radio, read the signal and then disable the radio without upsetting the
actual clock which sits on your wall showing the right time.

Personally I think someone could set up in business making interfaces for
these that plug (piggy back style) in to computer serial ports and load the
time using a TSR (is that right? I dont use PC's).

If anyone is wondering how a 'handed' radio clock works ! you set the time
to the previous hour, insert the battery and press a button on the back to
move the second hand to 12. You then leave it a couple of minutes and it
sets itself. On clock changes it either moves quickly on an hour or stops
for an hour in the middle of the night (no I am not sad enough to have
stayed up last night to watch it!).

Any more info needed - just ask.

--
Adrian, at home... (my views and opinions, of course, E&OE)