2017-09-15 EMF 2018 Collaboration Meeting

Where / when: Nottinghack, studio; 2017-09-15 (Fri), 19:15 ish

Attendees: Ian D, Matt L, Daniel S, Mouse.

Proceedings

Sensors

The obvious choices are optical: infra red or visible lasers.

• The signal can/should be modulated somehow to send a little bit of data
  • Could just be some way to ensure light comes from a gun rather than some other light source
  • Could also include some unique ID for a specific gun, so targets may know who shot them
• How do IR sensors respond to daylight? The targets will be in a marquee, but there may well be daylight flooding in, and they will be facing to the door / open section
• We could try to get hold of some sort of Quasar-like system, or find an open source Quasar-like project to work from. For sure this already a solved problem

Possible target effects

• Squirting water
• Air vortex
• Bubble machine
• Smoke machine
• Bell / clang
• Tin can alley
• Chicken house
• Nerf gun (how to reload?)
• Rumble / vibration
• Spinning things
• Play audio
• Projector / game, e.g. Tetris
• Jacob's ladder
• Smoke machine?

Networked vs. standalone targets

Networking targets with RS485/HC12/other technology, pros:

• Can have more sophisticated play
• Can have per-player scores
• Central brainbox can do things like tweeting etc, while keeping targets simple / cheap
• Would want string isolation of target logic and effects (i.e. motors and other loads should be self-powered and create minimal noise on serial bus)

Beginnings of as basic target board

• optical sensor
• low-cost micro controller
• place for relay
• RS485 connection

When hit, these basic target boards would do some standardised action, like trigger the relay for 1 second. The isolated side of the relay would be connected to whatever mechanism the maker of the target needs to create an effect.

Case-study effects

We talked through how some effects might be implemented to see if that would fit with the basic target board concept...

Spinning tea-pot

• basic target board connected to effect by relay
• effect would have microcontroller + motor driver + motor + the physical teapot
• relay would connect a pulled-up data pin to ground
• arduino controls motor to spin teapot
• triggering would be limited to one trigger per second or however long the target board takes to reset
• arduino code would have to be able to re-trigger half way though performing the effect, and handle this gracefully

Water shooter

Thinking through how to implement the classic hillbilly rifle shooter

• When hit, turns manikin towards shooters, squirts water at them, turns back
• Might want to know WHICH gun shot it - would need to get ID of gun from RS485, so can't just be connected to relay
• Could put it on the RS485 bus, listening for events from the right target and extracting gun ID from traffic

Tetris

• Projector / large screen with Tetris
• Four targets perform spin and move operations
• Would probably be implemented with an RPi
• GPIO inputs from four separate relays, or could monitor RS485 traffic

Sequences

• Special combos might trigger extra effects (e.g. setting off a sub-set of the targets simultaneously)
• Would require targets to be able to be triggered from central brainbox (i.e. over RS485)
• Maybe all targets should be triggered from RS485