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Ultimate 2 DDS lamp flashing

"hellozerohellozerokl7"
 

Morning Chaps - Ive an oddity and need to spend more time on it but I built the unit and it works fine with the GPS off. I cant get the NMEA and GPS to function at the moment (but that may be resolved as new code chips arrived from Jpan overnight) but one thing I noticed was that with the power off to the unit (+5) the red led on the DDS would flash either during the Jupiter GPS NMEA code sequence (more like pulse rapidly during the string) and secondly when I did have the 1pps connected the LED would again flash at the pulse came in - again powe r isnt on. I cant see any errors on the board or contacts between the pps input pin - wonder if its me... Cheers Laurence KL7L Wasilla AK
Hans Summers
 


Hi Laurence

Does everything work fine when the unit is properly powered up?

I noticed the same effect too. I don't think it is anything much to worry about. Modern LED's emit a small amount of light even at very low currents. Probably there is some kind of leakage through the AVR chip from the 1pps line or the Serial data line, and it finds its way to the 5V line somehow and allows some small current to flow. Something like that. I don't lose any sleep, worrying about it... as long as everything works as it should when power is applied etc.?

73 Hans G0UPL


On Tue, Jul 30, 2013 at 8:55 PM, hellozerohellozerokl7 <hellozerohellozerokl7@...> wrote:
?

Morning Chaps - Ive an oddity and need to spend more time on it but I built the unit and it works fine with the GPS off. I cant get the NMEA and GPS to function at the moment (but that may be resolved as new code chips arrived from Jpan overnight) but one thing I noticed was that with the power off to the unit (+5) the red led on the DDS would flash either during the Jupiter GPS NMEA code sequence (more like pulse rapidly during the string) and secondly when I did have the 1pps connected the LED would again flash at the pulse came in - again powe r isnt on. I cant see any errors on the board or contacts between the pps input pin - wonder if its me... Cheers Laurence KL7L Wasilla AK
"hellozerohellozerokl7"
 

Thanks Hans - I couldnt see anything wrong but for a while I thought I had a X connections somewhere - but when the serial and 1 pps lines into the AVR are single points I came to the same conclusion.

Ive not got the NMEA or 1 pps working as of yet but about to plug in the lastest rev.

Has anyone been successful with the Z3801A GPS with the Ultimate 2 or had to do a level conversion jobby? I see a circuit to translation from differential to TTL and may have to do that?

Regards from Alaska and thanks for all the hard work.

Laurence

--- In QRPLabs@..., Hans Summers <hans.summers@...> wrote:

Hi Laurence

Does everything work fine when the unit is properly powered up?

I noticed the same effect too. I don't think it is anything much to worry
about. Modern LED's emit a small amount of light even at very low currents.
Probably there is some kind of leakage through the AVR chip from the 1pps
line or the Serial data line, and it finds its way to the 5V line somehow
and allows some small current to flow. Something like that. I don't lose
any sleep, worrying about it... as long as everything works as it should
when power is applied etc.

73 Hans G0UPL


On Tue, Jul 30, 2013 at 8:55 PM, hellozerohellozerokl7 <
hellozerohellozerokl7@...> wrote:

**


Morning Chaps - Ive an oddity and need to spend more time on it but I
built the unit and it works fine with the GPS off. I cant get the NMEA and
GPS to function at the moment (but that may be resolved as new code chips
arrived from Jpan overnight) but one thing I noticed was that with the
power off to the unit (+5) the red led on the DDS would flash either during
the Jupiter GPS NMEA code sequence (more like pulse rapidly during the
string) and secondly when I did have the 1pps connected the LED would again
flash at the pulse came in - again powe r isnt on. I cant see any errors on
the board or contacts between the pps input pin - wonder if its me...
Cheers Laurence KL7L Wasilla AK

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