I am currently looking for a low cost, I mean cheap, GPS solution for my Arduino Leonardo. What I need is a simple solution which offers me a high precision 1 pulse per second output of the GPS to my Arduino.
I borrowed 2 Adafruit GPS loggers. Unfortunately one seems to be broken, but the other works fine. But I don't need the sd card and the shield. I also couldn't find the accuracy of the 1pps (about 40 eur).
The other thing I found is the xbee gps. It's cheaper and the data sheet states to have 30 ns acuracy of the 1pps. So it looks nice. (about 25 eur).
But what could you advice for me? It should be cheap and simple, so basically I don't need a shield as long as I can attach it by myself to the pins of my Arduino :).
There are GPS modules available on ebay now with prices ranging down to about US$ 17 . You then need a minimum of four pieces of wire to connect to power, ground and serial pins of arduino.
The difficult part is usually how to solder the wires onto the module.
The accuracy of the 1 pps signal is going to be far more accurate than any possible need that you could have. Instead of worrying yourself about whether one brand of chip is more "accurate" than the other brand by a few nanoseconds, you need to consider the implications for application of the GPS not being able to get a signal.
ahhh, I think it's nice. I don't have to solder anything, and the 1pps accuracy is stated with 10ns which is very nice. It could be a little bit cheaper :D, but I couldn't find other breakouts in that prize range.
michinyon:
There are GPS modules available on ebay now with prices ranging down to about US$ 17 . You then need a minimum of four pieces of wire to connect to power, ground and serial pins of arduino.
The difficult part is usually how to solder the wires onto the module.
what modules do you recommend! I also found some in that range like EM406a and others, but at least for this one I couldn't find specification of the 1pps accuracy. and doing easy soldering is okay, but it should be explained somewhere.
michinyon:
The accuracy of the 1 pps signal is going to be far more accurate than any possible need that you could have. Instead of worrying yourself about whether one brand of chip is more "accurate" than the other brand by a few nanoseconds, you need to consider the implications for application of the GPS not being able to get a signal.
I need them for synchronization of two different boards, where one triggers the broadcast of a RF signal that will be received on the other side. On the reception side the 1pps triggers a counter that counts as long until the signal is received. So I want to minimize the sources of delay and that's why the 1pps should be as accurate as possible.
the absence of signale is another thing, but not my main concern :). I have time to wait until the signal is back again.
GPS module with external antenna connection may give flexibility on placement of the electronics, with antenna able to be placed at a better signal reception location. GPS modules that sells for $40 ~ $60 on hobbyist sites are standard ones that require position fix to generate accurate 1PPS signal, which requires 3 or 4 satellite signals. More expensive timing mode receiver has self-survey mode or static mode function, such that after receiver location is determined, accurate 1PPS signal could be maintained down to receiving 1 satellite signal.
