TriggerBox

Programmable MIMO synchronization device: software, and hardware design

Input

• Active Triggers (source): Read TTL signal rising edge (5V) from the TriggerBox system. Intend to coordinate with a conducting manual push-trigger.
• Passive Triggers (sink): Read TTL signal rising edge (5V) from other systems, current rated to 20mA. e.g., the trigger signal from a motion controller or high-speed cameras.

Output

• Flash: A driving pules to standard LED diode
• Beep: Drives a buzzer with specfic tone.
• Trigger Signal: Give a TTL signal to other systems, 5V 20mA or amplified with LM386 amplifier.
• Gate: keeps high when the system gets armed, low when disarmed.

Logic

V2.6: General purpose version

• The system reads a trigger input signal, either manual or motion pules,
• The system gets armed,
• flashing and buzzing with a programmed pattern,
• trigger output sent out simultaneously, gate keeps high.
• Another Trigger input will disarm the system with a flash, buzz, and trigger output.

V3.01: New features added to work with PIV/Laser system

• Take inputs from the safety curtain and PTUX to control the gate of the DM laser
• Armed by push trigger
• Open the laser gate only if the system is armed and LaVision is ready(PTU output HIGH)
• The system disarmed by pushing the manual trigger again or objects fall through the safety curtain

Software

• TriggerBox Arduino code to drive the box
• TriggerFinder: {rising falling] = TriggerFinder( High, Low, State)
  • Matlab function for postprocessing the trigger signal
  • Digitize: Set any value lower than Low to 0 and any value higher than High to 5
  • Derivation and find a peak to find all rising and falling edge
• Beepfinder:
  • find the beep tone collected by microphone in postprocessing
  • short time Fourier transformation (STFT) to present a time history of spectrum
  • Cross-correlation to find a beep pattern on the STFT
• InlineTrigger
  • Generate a brust of pluses on the receiving of one TTL pluse.

Hardware

The listed hardware has been testified to be completable. Other alternatives may also be found since they are just common components

• Arduino (nano, Uno for legacy versions)
• Shield board: see PCB design
• 3-24V buzzer, for example, which is loud enough :)
• Led diode, which is really bright...
• LM386 Amplifiers
• LED driver

PCB Design

• The shield board is customized for the interface with hardware.
• The design can be found in the PCB design .zip file.
• we choose JLC as our manufacturer.