Can we feed the opentracker signal into the G1 mic jack and use it as a trigger?<br><br><div class="gmail_quote">On Fri, Mar 19, 2010 at 10:43 AM, Greg Stramback <span dir="ltr"><<a href="mailto:grog@piratelabs.com">grog@piratelabs.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">Good point Nils. It's kind of a shame we don't have the weight allowance that would allow for a centralized GPS based timing platform that could synchronize the clocks. Eh, weight alone wouldn't be the problem anyways. The expense is nothing to sneeze at. <div>
<br></div><div>Besides, we're only using one device's data as a reference to compare the other with. A reference packet every 4 mins will fit in nicely with the regular 30sec interval packet. </div><div><br></div>
<div>-g-<br><br><div class="gmail_quote"><div class="im">On Fri, Mar 19, 2010 at 8:51 AM, <span dir="ltr"><<a href="mailto:nils@shkoo.com" target="_blank">nils@shkoo.com</a>></span> wrote:<br></div><div><div></div>
<div class="h5"><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
I think it'll be tough to avoid them interfering with each other except if<br>
we have some kind of synchronization mechanism.<br>
<br>
I think that if we try to configure the clocks to be at the same rate,<br>
we'll get pretty close but not exact. Then when they start interfering<br>
with each other it will take longer for them to stop.<br>
<br>
I think the best thing to do would be to set the intervals as follows:<br>
<br>
opentracker: 31 seconds<br>
<br>
g1: 127 seconds<br>
<br>
Guestimating the transmit time as 1 second, that way they will only line<br>
up on the same second once every 3937 seconds, so most of the beacons<br>
should be fine even if the timing isn't exact.<br>
<br>
If we tried to line them up on 30 seconds and it ended up with the<br>
following intervals:<br>
<br>
opentracker: 30 seconds<br>
g1: 30.1 seconds<br>
<br>
Then when they line up, they would transmit on the same second for 10<br>
beacons in a row, so we could lose a whole 5 minutes of transmitted data.<br>
<br>
Ideally, the thing to do would be to make them able to listen to telle<br>
when the other is transmitting. I'm pretty sure the opentracker can do<br>
collision avoidance of some sort, but the android code not so much right<br>
now.<br>
<br>
-nils<br>
<div><div></div><div><br>
On Thu, 18 Mar 2010, Albert Alexander wrote:<br>
<br>
> Sounds right to me, but I'll defer to Nils. I know they do not transmit<br>
> simultaneously.<br>
><br>
> On Thu, Mar 18, 2010 at 8:44 PM, Christie Dudley <<a href="mailto:longobord@gmail.com" target="_blank">longobord@gmail.com</a>>wrote:<br>
><br>
>> I think the idea we had was that they were each sending at the same<br>
>> interval. If they maintain even reasonably good clocks and aren't aligned,<br>
>> they shouldn't ever overlap. I think their duty cycle is low enough that<br>
>> this wouldn't be a problem.<br>
>><br>
>> (I'm assuming that you mean amateur radio, not an actual walkie-talkie,<br>
>> here?)<br>
>><br>
>> Christie<br>
>> _______<br>
>> "We also briefly discussed having officers replaced by very small shell<br>
>> scripts." -- Noisebridge meeting notes 2008-06-17<br>
>><br>
>> The outer bounds is only the beginning.<br>
>> <a href="http://www.flickr.com/photos/genriel/sets/72157623376093724/" target="_blank">http://www.flickr.com/photos/genriel/sets/72157623376093724/</a><br>
>><br>
>><br>
>> On Thu, Mar 18, 2010 at 6:24 PM, Albert Alexander <<br>
>> <a href="mailto:albert.alexander@gmail.com" target="_blank">albert.alexander@gmail.com</a>> wrote:<br>
>><br>
>>> Nope, they transmit at separate times. We could use a fet to switch<br>
>>> sources but that's more parts and wires.<br>
>>><br>
>>><br>
>>> On Thu, Mar 18, 2010 at 6:10 PM, Greg Stramback <<a href="mailto:grog@piratelabs.com" target="_blank">grog@piratelabs.com</a>>wrote:<br>
>>><br>
>>>> I'm making the assumption that we're expecting a certain percentage of<br>
>>>> garbled / unreadable packets due to two audio sources being combined?<br>
>>>><br>
>>>> -g-<br>
>>>><br>
>>>> On Thu, Mar 18, 2010 at 5:56 PM, Albert Alexander <<br>
>>>> <a href="mailto:albert.alexander@gmail.com" target="_blank">albert.alexander@gmail.com</a>> wrote:<br>
>>>><br>
>>>>> The walkie-talkie is getting audio from two sources. I suggested using a<br>
>>>>> splitter to combine the sources, but this will load down the output<br>
>>>>> transistors unless we add two resistors in series before the splitter. 10k<br>
>>>>> is fine. This will attenuate the current of each signal. We could use a<br>
>>>>> summing amp if we want to avoid the attenuation, or we could just turn up<br>
>>>>> the volume.<br>
>>>>><br>
>>>>> Will test G1 audio out AC coupling tonight after 5moF<br>
>>>>><br>
>>>>> _______________________________________________<br>
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>>>>><br>
>>>><br>
>>><br>
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>><br>
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