Interface Specifications

Object

This document describes the interface provided by the Shutter Lover measurement tool.

Interface version

This document describes the following version of the interface:

1.0.0

Interface description

Physical interface

• The Shutter Lover is interfaced to a personal computer through a USB cable.
• The Shutter Lover is seen by the host computer as a virtual COM (serial) port.

Data format description

• The Shutter Lover outputs measurement data in json format.
• Each json data is streamed in a single line. Each line is ended with #CR/#LF characters
• The remote application shall ignore data that is not in json format

Data Example

For readability purpose, the json message is written multiline. The actual message is single line

{ 
  "eventType": "MultiSensorMeasure",  
  "unit": "microsecond",  
  "firmware_version\": "1.0.0", 
  "bottomLeftOpen": 0, 
  "bottomLeftClose": 989,
  "centerOpen": 7654,
  "centerClose": 8678,
  "topRightOpen": 12345,
  "topRightClose": 13456,
  "bottomLeftOpenOffset": 6,
  "bottomLeftCloseOffset": -5,
  "topRightOpenOffset": -7,
  "topRightCloseOffset": 2
}

Data content description

Field	Type	Description
eventType	string	Must be "MultiSensorMeasure" in order to be taken into account
unit	string	Allways "microsecond"
firmware_version	string	Must be "1.0.0". This document describes the data generated by this version of the firmware
bottomLeftOpen	Integer	Timestamp of begin of Light Detection on the Bottom Left sensor. The first even that occurs has a timestamp set to 0. The later events are the time difference compared to this first event. Expressed as a number of microseconds. A negative value mean no value (bad positionning of the sensor or shutter misbehaviour).
bottomLeftClose	Integer	Timestamp of end of Light Detection on the Bottom Left sensor.
centerOpen	Integer	Timestamp of begin of Light Detection on the central sensor.
centerClose	Integer	Timestamp of end of Light Detection on the central sensor.
topRightOpen	Integer	Timestamp of begin of Light Detection on the Top Right sensor.
topRightClose	Integer	Timestamp of end of Light Detection on the Top Right sensor.
bottomLeftOpenOffset	Integer	Offset to be added on the bottomLeftOpen value
bottomLeftCloseOffset	Integer	Offset to be added on the bottomLeftClose value
topRightOpenOffset	Integer	Offset to be added on the topRightOpen value
topRightCloseOffset	Integer	Offset to be added on the topRightClose value