[tech] Door Circuitry

Bob Adamson bob at ucc.gu.uwa.edu.au
Mon Aug 30 13:24:33 WST 2010


Well...this could have saved several hours of head scratching...

Door relay is alive again. Fixing the short in the lock and replacing the 
fuse in the modem fixed it, though it took a bit longer to sort out the 
power issues. Turns out the solenoid and modem are pretty power hungry, 
and don't want to work with a wall wart.

For future reference, you send ATH1F over serial to trigger the relay.

Bob

On Sun, 29 Aug 2010, James Andrewartha wrote:

> On Sun, 29 Aug 2010, David Adam wrote:
>
>> On Sun, 29 Aug 2010, David Adam wrote:
>>
>>> On Sun, 29 Aug 2010, Bob Adamson wrote:
>>>> Sad news - our door relay has kicked the bucket. Somehow the electronic lock
>>>> got a short in it, killing the modem (!) that drives the relay. Of course,
>>>> being UCC, this modem was a complete box of hackery. Adrian and myself are
>>>> working on a simple circuit to replace it, but haven't had any luck yet.
>>>>
>>>> If anyone knows anything about how the old setup worked (particularly the
>>>> success/failure sensing in the binary) please give me a yell.
>>>
>>>> From http://www.ucc.gu.uwa.edu.au/services/door.ucc
>>>   The door lock is switched using the On-Hook relay of a modem. This
>>>   provides a cheap, reliable serial interface to the door lock.
>>>
>>> You need to send ATD (or possibly ATH) down the serial line to make the
>>> modem pick up the phone line. The thought occurs that you probably didn't
>>> know that this afternoon which may have been why you couldn't get it to work
>>> :-)
>>
>> Actually it's A0. I think.
>
> strings /usr/sbin/opendoor suggests 'ATH1F' and 'ATH0F'.
>
> -- 
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> # UCC Wheel Member     http://trs80.ucc.asn.au/ #|  what squirrels do best     |
> [ "There's nobody getting rich writing          ]|  -- Collect and hide your   |
> [  software that I know of" -- Bill Gates, 1980 ]\  nuts." -- Acid Reflux #231 /
>


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