I've now effectively finished this build and successfully had it running at our event this past weekend:
![Image]()
Here's a demo video of it running:
iframe
It ran for over 8 straight hours from a 10,000mAh USB powerbank. By the end of the day it had only dropped to about 75% (I still recharged it overnight but it wasn't necessary). With all lights on it draws about 330mA (0.33A), so it could have lasted 30hrs if needed.
The lower indicator lamp grids didn't look great, the LED beams were probably too close to the acrylic lenses. So last week I printed these little diffuser blocks to sit over them (using transparent PETG), they definitely spread the light more evenly:
![Image]()
The enclosure is made from foamcore covered with faux leather (self-adhesive carseat repair "leather"), so it weighs next to nothing:
![Image]()
It has embedded magnets to hold it in place.
The base is hinged so it can fold up, so the whole thing essentially flatpacks:
![Image]()
The entire shelf of equipment in the first photo (oscilloscope, Spectral Analyzer, and this new Signal Generator prop) fits into a single plastic tub for transport. Very important when you have a long walk to the carpark or across the venue floor during setup!
As for the animations, the three lower indicator lamp grids I based on what we could see in GB2. I stepped through the scene frame by frame and tried to record each position. Each grid could have one or two lamps illuminated, so my code replicates this (without replicating the exact position or timing). I think I'm close enough, but I may revisit this in the future.
For the six upper LED segment displays, GB2 is a little too blurry so I loosely based these on what we could see in that Firefly episode. Some of the displays just show random 4 digit numbers. One shows a random 3 digit number. Another shows a kind of clock display counting from 12:00 to 12:59. Another shows the numbers 60 through 99 rapidly counting upwards and looping. And the final display shows 40 years of Ghostbusters, from 1984 through to 2024![:lol:]( "Laughing")
Again I may revisit this but for now it's fine.
The buttons and switches don't do anything yet, except for the two large toggle switches which cut power to the TM1637 LED displays. I found that they draw a lot of current when powered on, so I need to disconnect them when uploading code to the ESP32 (or I get upload errors). Eventually I'll improve this but I needed a quick fix before the event and this was the easiest workaround.
On Sunday I did unfortunately fry the HT16K33 LED multiplexer board I was using for the lower displays, I tried to have all the LEDs lit up at once (for an unrelated test I was doing) and it obviously didn't like that. So we went without them for the rest of the day.
Luckily I made everything swappable (using PCB header pins) so it'll be a quick fix, literally just unplug the dead board and plug in a fresh one (after I probably add some extra resistors...).
The John Zabrucky (Modern Props) exhibit in Ohio is now over so I never managed to see any new reference photos for the original props, but they'll probably end up on display when their new Sci-Fi museum eventually opens to the public.
Finally, I recently came across a second Ghostbusters connection to the props.
Here they are with Melissa McCarthy in "Bridesmaids" (2011):
![Image]()
![Image]()
(1:35 in the Trailer)
Well, what do you know? Maybe there are three of the original props after all?
Here's a demo video of it running:
iframe
It ran for over 8 straight hours from a 10,000mAh USB powerbank. By the end of the day it had only dropped to about 75% (I still recharged it overnight but it wasn't necessary). With all lights on it draws about 330mA (0.33A), so it could have lasted 30hrs if needed.
The lower indicator lamp grids didn't look great, the LED beams were probably too close to the acrylic lenses. So last week I printed these little diffuser blocks to sit over them (using transparent PETG), they definitely spread the light more evenly:
The enclosure is made from foamcore covered with faux leather (self-adhesive carseat repair "leather"), so it weighs next to nothing:
It has embedded magnets to hold it in place.
The base is hinged so it can fold up, so the whole thing essentially flatpacks:
The entire shelf of equipment in the first photo (oscilloscope, Spectral Analyzer, and this new Signal Generator prop) fits into a single plastic tub for transport. Very important when you have a long walk to the carpark or across the venue floor during setup!
As for the animations, the three lower indicator lamp grids I based on what we could see in GB2. I stepped through the scene frame by frame and tried to record each position. Each grid could have one or two lamps illuminated, so my code replicates this (without replicating the exact position or timing). I think I'm close enough, but I may revisit this in the future.
For the six upper LED segment displays, GB2 is a little too blurry so I loosely based these on what we could see in that Firefly episode. Some of the displays just show random 4 digit numbers. One shows a random 3 digit number. Another shows a kind of clock display counting from 12:00 to 12:59. Another shows the numbers 60 through 99 rapidly counting upwards and looping. And the final display shows 40 years of Ghostbusters, from 1984 through to 2024
Again I may revisit this but for now it's fine.
The buttons and switches don't do anything yet, except for the two large toggle switches which cut power to the TM1637 LED displays. I found that they draw a lot of current when powered on, so I need to disconnect them when uploading code to the ESP32 (or I get upload errors). Eventually I'll improve this but I needed a quick fix before the event and this was the easiest workaround.
On Sunday I did unfortunately fry the HT16K33 LED multiplexer board I was using for the lower displays, I tried to have all the LEDs lit up at once (for an unrelated test I was doing) and it obviously didn't like that. So we went without them for the rest of the day.
Luckily I made everything swappable (using PCB header pins) so it'll be a quick fix, literally just unplug the dead board and plug in a fresh one (after I probably add some extra resistors...).
The John Zabrucky (Modern Props) exhibit in Ohio is now over so I never managed to see any new reference photos for the original props, but they'll probably end up on display when their new Sci-Fi museum eventually opens to the public.
Finally, I recently came across a second Ghostbusters connection to the props.
Here they are with Melissa McCarthy in "Bridesmaids" (2011):
(1:35 in the Trailer)
Well, what do you know? Maybe there are three of the original props after all?
Statistics: Posted by prodestrian — July 9th, 2025, 3:30 am