Disclaimer: I’m an engineer, not a pro film maker. Be advised.
My goal... haunted house level effects for the front door, again! If you didn't see the "Scary Door" from 2013, go see it now!
I wanted to create the sense of stifling... to overwhelm the visitor with light and rumbling sound. I figured red light would give the most horror feel with the matched sounds.
I used a Raspberry Pi B+Raspberry Pi B+, not on purpose, but I am glad I did. The B+ has more IO, which I took advantage of. In fact, I used almost every single free IO on the board! I will admit, four of the pins I intended as additional outputs and effects, but never did use them. Technically, as many light as can be afforded could be used on those additional outputs with external relays.
Let's break it down...
Here were my requirements of the Scary Porch
- Slowly brighten a series of red lights
- Dim the porch light in opposite the red lights
- Start a slow creepy sound at the start of the approach
- When the visitor reaches the door, switch sounds to a more shocking track
- When the visitor leaves, cut the sound, dim the lights as they leave
- Have a big button for resetting the whole system at any point
Project by sections
- Lights
All the light I used are AC... So, if you build this yourself, be safe.
I bought an innocuous porch light from home depot... which still sells incandescent bulbs. I was shock, but happy I didn't have to amazon prime them to me. This is connected to a Sunrom 1298 AC dimmer circuit.
I did amazon prime some "sunlite" red flood lights. Six of them to be exact. the overwhelming effect of the light is really only present directly under the lights. These are connected to another Sunrom 1298 AC dimmer board. Don't worry, the dimmer board can handle 12A of 120VAC... so, no issue. But, touch the Sunrom boards and die...
Personally, I found that more scary than the entire project.
- Sensors for approach
Like in the Scary Door project last year, I used an Enforcer Retro-Reflective Sensor.. In fact, I used four. I figures like approximating a curve, I could approximate the visitors approach. Four sensor points I thought would be good enough.
- sound
The sound was probably the most difficult part. I had to mix two tracks that would accomplish ambient creepy and a total shock. So, I sampled a lot of different sources for this. I played everything on a stereo that I found in the garbage a long time ago. It seems to have worked out well.
- Relay output (Not used)
I actually put in four additional outputs for either more lights or effects, but I never used them. However, I was planning on creating a sense of people/things behind the visitor using cutouts in front of additional lights... perhaps for next year.
The difficulties
- Mounting the system and long camera cable
- Fire/Death
When working with AC and circuits that use AC, you never know what may happen.
Pics and system
Smack dab on a boardganizer, I placed the Pi B+ and the Sunrom dimmer circuits close to the edge. I had to drape the AC lines down the side. I took the GPIO on the Pi and spread the leads liberally around the breadboard. Most going to the 16 digital lines of the dimmer boards. See the four in the middle? They were meant for the four extra outputs I never used.
This is the full setup from a distance. The sensors would typically be placed out of sight on a porch. For me, I didn't have that luxury. See the black squares on the left side? Those are the reflectors for the sensors placed on the other side.
The effect on, and the effect off. Could be redder... if you ask me.
Block Diagram and Design
Code
This portion was fairly straight forward. Count up and down a 256bit number for the Sunrom dimmer circuits. Play sound with OMXPlayer call outs. And constantly look for the reset/EStop button push.
BOM
| Quantity | Price | Vendor | Part # | Description | |
| 1 | $40 | $40 | element14 | 68X0156 | Raspberry Pi model B+ |
| 1 | $16.40 | $16.40 | element14 | 88W3963 | BUD Boardganizer |
| 1 | $7.35 | $7.35 | element14 | 56T0249 | BREADBOARD, SOLDERLESS, 400 TIE POINTS |
| 1 | $49.95 | $49.95 | element14 | 44W3511 | BUDGET PACK, RASPBERRY PI (Mostly unused, only for parts) |
| 1 | $5.45 | $5.45 | element14 | 88W3962 | Bud Wire Kit |
| 2 | $7.95 | $15.90 | Sunrom | 1289 | Sunrom 1289 |
| 2 | $4.95 | $9.90 | HomeDepot | AC power strip | |
| 6 | $7.95 | $47.70 | HomeDepot | Worklight | |
| 6 | $11.69 | 70.14 | Amazon | BR38 RED OUTDOOR FLOODLIGHT BULB 100 WATTS | |
| TOTAL | $262.79 |
Other uses of the system
- Lighting and sound displays.
- Parties... play fun songs with colorful lights.
If I had more time and money
- I wanted to add a vibrating mat that vistors would stand on in front of the door. The idea is to give them a jolt they would feel through their shoes matched with the sound.
- The sounds can get annoying after a while... randomizing the tracks would be a good idea.
- More lights, of course.
- Better sound.
Happy Halloween 2014!!!
C
See more news at:
