Hi Hector,
I have built both kits you mentioned and they both worked ok.
The Goldpic is more sophisticated in some aspects since it used a PIC, LCD, etc, but is also more basic in others since it only takes one sample and there are no means of trying different things such as change delay, etc.
I was able to come very close to Hill's posted target depth chart with my finished PI. It worked fine, but I found this PI to be quite restrictive if a person wants to do much experimenting, which was something I personally wanted to do. Due to the design, modifiying it was going to be a real challenge.
The HH is a more versatile learning tool in that basically all key PI controls can be adjusted. One can adjust the pulse length, the pulse frequency, the delay and the sample width, to name a few. This allows a person to see just what happens when such controls are adjusted.
So, I guess it is more of a matter of just what you want to do as to which PI you should consider. If you are just looking to build a PI for the fun of it and want one that works, then either project is fine.
If you are looking to learn more about how PI's work and what happens when things are adjusted, then the HH would probably be a better choice.
I hope this helps.
Reg
