On 29/05/2013 15:50, Andy Cutland wrote:
The U2 refused to update the
time so I thought something was wrong with my gps connections. I
measured the voltage at pin 7 which showed 0.79v with a similar
voltage showing on pin 8. Does this sound correct. I couldn't
detect anything on the pps output pin (not sure what settings i
need on the scope for this). I am going to take another look at
it tonight with fresh eyes and a clearer head !
Andy
Something is wrong re pin7 showing? 0.79v. you have applied your 3v
supply and here and you would expect to see that value, likewise
with pin 8 the 10k should pull it up to the supply voltage.
How have you derived your 3v supply.
Is there a short somewhere in connecting up. Hopefully the GPS
Module is not pulling down the supply.
When you get the voltages right why not connect the Data also, this
will update the clock to real time and is easily visible on a scope
and the result is visible on the U2 nicely.
The PPS out I could no see on my scope the only detection of its
presence was by setting the scope to trigger on its leading edge.
Bear in mind that the PPS needs a 3D lock and hence a good view of
the satellites, the results on the U2 always come later than the
real time update.
73 Eddie G3ZJO
