TriggerBox

Programmable MIMO synchronization device, software and hardward design

Input

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

Output

• Flash: A diriving pules to standrad LED diode
• Beep: Drives a buzzer with specfic tone.
• Trigger Signal: Give a TTL siganl to other system, 5V 20mA or amplified with LM386 ampifier.
• Gate: keeps high when system get armed, low when disarmed.

Hardwares

Listed hardware has been testified to be complitable. Other alternaitves may also be found since they are just common comppnents

• Arduino (nano, Uno for lagency versions)
• Sheild board: The shield board is customized for the interface with hardwares. The design can be found in another folder, we choose JLC as our manufacture.
• 3-24V buzzer, for example, which is loud enough :)
• Led diode, which is really bright...
• LM386 Amplifiers
• LED driver

Logic

V2.6: Gereral purpose version

• The system read a trigger input signal, either manul or motion pules,
• The system get armed,
• flahing and buzzing with programmed pattern,
• trigger out put sent out simultaneously, gate keeps high.
• Another Trigger input will disarm the system, with a flash, buzz and trigger output.

New to V3.01

• Take inputs from safety curtain and PTUX to control the gate of 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 safty curtain

Software

• TriggerBox arduino code to drive the box
• TriggerFinder: {rising falling] = TriggerFinder( High, Low, State)
  • Matlab function for postprocessing the trigger siganl
  • Digitize: Set any value lower than Low to 0 and anyvalue higher than High to 5
  • Derivation and find peak to find all rising and falling edge
• Beepfinder:
  • short time fourier transfromation (STFT) to present a time history of spectrum
  • Cross corelation to find a beep pattern on the STFT