DPReview.com is closing April 10th - Find out more

Hot-shoe signal to external GPS

Started Apr 24, 2017 | Questions thread
OP DPR_gio New Member • Posts: 3
Re: Hot-shoe signal to external GPS

BobORama wrote:

Hi,

You can implement an edge triggered debouncing circuit. It will activate on the rising edge and the output will stay logic high until a certain time elapses. I am quickly cribbing from the Internet, and this diagram has more than you actually need:

See http://www.talkingelectronics.com/projects/100%20IC%20Circuits/1-100_IC-Ccts.html

The left most pair of NAND gates acts as a debouncing circuit / latch which will set pin 3 logic high for a predetermined amount of time when the leading edge of the input to pin 1 is detected.

The right hand pair of NAND gates forms an square wave generator for driving the speaker. Unless you need an audible alarm when the shutter goes off - you can skip that and the transistors

So no matter how short the duration of the input pulse, the output from Pin 3 will stay high for as long as indicated by the R-C circuit in between the two left most gates. So for, say, a 100ms pulse you would want 1 microfarad and a 10K resistor? Or a small potentiometer so you can adjust it later.

Thanks a lot Bob; I've doing some checks/tests and I think there might be a problem with the GPS configuration/set-up: I've posted on the Ublox forum hoping someone can shed some lights on this matter.

Thanks again for your suggestion.

Regards

Giovanni

Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow