New Launch Controller
If you've been following along, I've finally received the final PCBs from production and I've populated them with components to implement the lockout function for the launch controller.
You may be asking yourself, "What is this lockout function all about?" Well, if you review the earlier posts in this forum topic, you'll see that the launch controller will have many more switches than the present/existing launch controllers. This controller can control up to 24 pads from a single unit. The design places six switches into four banks. This allows a way to coordinate bank with the existing 6-pad launch racks. Also, this controller is equipped with a single launch button. To launch a rocket or multiple rockets (ie. drag race), the switch for those pads is enabled and then, the launch button is pressed. This is fine for launching; however, selecting multiple switches when performing continuity testing would be both problematic and confusing. Therefore, when the controller is in continuity test mode, there is a lockout to insure that only one pad is selected for continuity testing at a time.
The following is a video of a "mockup" to demonstrate the lockout logic. There are four sets (banks) of six switches (pads) created with some micro push-button switches. I tried to segregate the banks using colors — Red, Blue, Green and Yellow. — for the banks. The micro switches are also color coded; however, that was only for my sanity when I was breadboarding and the connecting ribbon cables follow the same color coding. I also elected to use colored LEDs for the same reason.
BTW, if you compute the permutations of 24 switches, you'll find that it's greater than 6×10²³!
Can't wait to try the real thing.
Shouldn't be that hard (he says confidently). Since only one bank can be active at any time, just do the permutations for one bank of six and repeat for the other three banks.
Quote from Ckirlew on February 17, 2026, 8:29 amShouldn't be that hard (he says confidently). Since only one bank can be active at any time, just do the permutations for one bank of six and repeat for the other three banks.
Nope. All the banks can be and are active.
I'd originally setup lockouts for the individual banks but at one of our launches there was a drag race. The rockets were dispersed on the launch racks and on the launch rails. That's when I decided it would not be a good idea to limit launches to banks of six and I redesigned the lockout logic boards as a result. IF you should want to, it will be possible to launch a drag race using all 24 circuits simultaneously.
Anyway, the total permutations of 6 is 6! or 720. 720 • 6 is 2,880. That is not the equivalent of 6!•4 = 24!
OK, I either mis-remembered or mis-read. It makes sense to be able to launch from multiple racks. Really looking forward to pushing some buttons (on the controller).
Now the big question. In a couple of years we will have our 20th anniversary as a club. Can we launch 20 rockets in a drag race?