Re: [Paparazzi-devel] lisa has a different GPS interface?

[Marvin Wang]

hi Christophe
the module i bought is 5H with an active antenna(18*18mm) and a 3.3v regulator

2012/6/25 Christophe De Wagter <address@hidden>:
> could you tell us a little more about which GPS module you exacly bought? We
> have seen some boards with wrong antenna impedance (board thickness not
> matching the gerbers)
>
> -Christophe
>
>
>
>
> On Mon, Jun 25, 2012 at 4:59 PM, Tilman Baumann <address@hidden> wrote:
>>
>> On 25/06/12 15:52, Marvin Wang wrote:
>>>
>>> hi Chris,
>>>
>>> i had tried that use ublox center in windows and it get lock within 1
>>> minute,(first time), but when it goes on my lisa/m2.0, it is another
>>> story. the GPS is very hard to get locked,  up to 10~20 minutes to get
>>> locked on my balcony.  in the field it takes more than 2 minutes. i
>>> dont know what causes this.
>>
>>
>> How is it if you power the Lisa board from USB?
>>
>> I might have observed the same pattern. I have not looked much into it,
>> but I had massive problems recently getting a stable fix. And the only
>> change was that I used a UBEC to power the +5V line on Lisa.
>> I might need to clean that up a bit. I don't expect that UBEC to be any
>> good (no name 3A 5V thing) but since everything it ought to power actually
>> runs on 3.3V I thought it might not matter so much.
>> I thought the LDO will smooth that out. But perhaps they don't...
>>
>> Can't prove those issues yet. Just want to mention since our experience
>> seems similar.
>> Any tips what I should try to clean the power rail?
>>
>> +5V is looped through a ferrite ring a few times.
>> Modem runs directl on 3.3V rail of Lisa. (could also hook it up on 5V. I
>> soldered VCC behind the voltage regulator on the XBee breakout because this
>> serial port was only 3.3V by default. But it's switchable)
>> uBlox MAX-6Q runs on 5V with it's own voltage regulator for 3.3V
>>
>>
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>
>
>
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