Well the ASTRO pcb design has been sent to the manufacturer today. Its in some way is a leap of faith that the layout is correct and that it meets both physical and electrical requirements and that nothing has been overlooked. There is a big temptation to add every last function, but eventually, you have to let it go. Smaller connectors, a more efficient voltage converter and a smaller programming port have been added.
I decided for one thing, that the board would only be powered from the attached cable. This may seem odd because the camera is capable of powering the controller, however, on the ground, when things lock up (which they do frequently in the real world) it is good to be able to reset the system by pulling the power.
The camera can be run with or without its battery in place. I have it arranged that the remote handheld unit will power the board and operate the camera with a small internal battery. However, if the user connects an external power supply (9-15V @2A), the handheld unit will also power the camera without the camera battery. An option to remotely charge the camera battery instead, can be provided.
The initial plan is to utilise Ethernet cable with RJ45 connectors between the handheld remote and the camera. Two pairs for DC power and one pair for RS485. Audio and composite video is available via 10-pin USB if required and the remaining pair may help in this.
24 hours into production the PCB maker has posted a graphic illustration of the production stage – Exposing the PCB.
And now the Tin Stripped process is completed.
Solder mask – process cured 31/3/2017
The manufacturer posts these images as the board is being processed. This helps spot mistakes that might cause an issue at a later stage. So far all looks good, there are some issues concerning silk screen text placement and size. Two common vias have merged but is not a problem in this case. Resistor and capacitor outlines have not printed either.