I soldered a 4-pin header to the GPS module so two days ago I decided to plug the module directly in to the solderless breadboard as it would simplify connecting to it. It was ok at first but then it seemed the light that blinks when there is a GPS lock wasn't blinking as it should. It was blinking, then it seemed to stutter, blink some more, then finally stopped. I thought perhaps the unit had died in some way as it had been reliable until then. I checked the data coming from the unit and it was sending data but had no valid GPS data. I went on to other things for a while and forgot about it.

Yesterday morning I remembered I had left it running. I found the light was blinking as it should and it was giving out valid GPS data. Phew! The unit wasn't bad after all. Later in the day I noticed it had stopped blinking again. Today I took the unit off the breadboard and moved it back to where I had originally had it and its working again. Satellite reception must be marginal on my workbench. It would be nice if I could use the antenna from my GPS disciplined oscillator. It has a long cable so I can hang it near a window but it uses a different (larger) connector so I can't use it with the GPS receiver module used in this project.

During the time I was having problems with the reception of the GPS satellites I completed the first version of the PCB layout for the interface board. It confirms I can wire everything up in the small space I have available but the PCB
isn't usable. The connectors for the camera and shutter release aren't where they should be for ease of use. I've been thinking of how to position the connectors, switches, and LED for a while so I have determined where they need to go for the device to be usable and not to interfere in any way with the regular operation of the camera. I haven't quite decided whether the LED should be visible on top or on the side with the switches.

In order to do a PCB layout that might be usable for a working prototype I need to do some 3D modelling to finalize parts placement and determine clearances. I've seen some GPS receiver devices which interfere with the proper operation of the built-in flash unit when they are mounted on the hot shoe. I want to avoid that with my design. First step is to model the top of the camera with the built-in flash unit in the raised position. I've already made model for the GPS receiver module and antenna. I need to create a few more models for the parts on the interface board and I will be able to determine the final position for some of the parts. Once I have that information I will redo the PCB layout.