Stupid me. Although particularly obvious, this had totally passed me by,
I'm so use to saving power where I can, it comes automatically to me now!!

I think this combined with a GPS reciever could be the solution to all my
problems!

As to why they need to be that synced, (thats a secret :P). I've
questioned the spec a few times, but I'm told it's necessary by the powers
that be.

Mat


> Maybe I missed something - this sounds too easy.
>
> Power at the transmitter is effectively unlimited, right? (o.k. 11 watts,
> but that's still lots) Why not just send a time signal out continuously,
> and let the receiver read it whenever it wakes up? The transmitted data
> stream could be a time packet followed by some form of sync pulse -
> something like $5A5A, then the reciever snychronizes with the next rising
> edge.
>
> I'm more interested in why the units need that level of sync.
>
> -Denny
>
>
>
>
>> I'm currently working on a design with a specific problem, which I'm
>> hoping someone will have come across before.
>>
>> Essentially I have several remote circuits, which must remain
>> unconnected.
>> They all need to be synchronised within 100 Micro Seconds.
>>
>> Essentially we are looking at deploying a beacon transmittor which will
>> send out a pulse at known intervals and have low power recievers on each
>> circuit which come out of hibernation at the required interval, to reset
>> the onboard clocks appropiatly.
>>
>> We are looking at achieving 100m range (indoors), however power at the
>> beacons is not a significant problem (we have 11Watts available, and
>> these
>> are not battery powered). Power at the recievers is crucial, each
>> circuit
>> is powered by battery and must be capable of running for a minimum
>> period
>> of a year. Physical battery size is not crucial but small is better :)
>>
>> Does anyone have any other suggestions how to achieve the required
>> synchronisation, or can anyone suggest any suitable radio IC's/circuits
>> which could be used as I am stuggling to find anything useful via google
>> (must be using the wrong keywords)
>>
>> Any suggestions or comments would be greatly appreciated.
>>
>> Mat
>>
>>
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