Shell - Motion Detector Bricklet

This is the description of the Shell API bindings for the Motion Detector Bricklet. General information and technical specifications for the Motion Detector Bricklet are summarized in its hardware description.

An installation guide for the Shell API bindings is part of their general description.

Examples

The example code below is Public Domain (CC0 1.0).

Callback

Download (example-callback.sh)

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#!/bin/sh
# connects to localhost:4223 by default, use --host and --port to change it

# change to your UID
uid=XYZ

# handle incoming detected motion and  end of detection cycle callbacks
# note: this chaining of two dispatches assumes that a detected callback is
#       always followed by a detection cycle ended callback
tinkerforge dispatch motion-detector-bricklet $uid motion-detected\
 --execute "echo Motion Detected;
            tinkerforge dispatch --duration exit-after-first motion-detector-bricklet $uid detection-cycle-ended\
             --execute 'echo Detection Cycle Ended \(next detection possible in \~3 seconds\)'"

API

Possible exit codes for all tinkerforge commands are:

  • 1: interrupted (ctrl+c)
  • 2: syntax error
  • 21: Python 2.5 or newer is required
  • 22: Python argparse module is missing
  • 23: socket error
  • 24: other exception
  • 25: invalid placeholder in format string
  • 26: authentication error
  • 201: timeout occurred
  • 209: invalid argument value
  • 210: function is not supported
  • 211: unknown error

Command Structure

The common options of the call and dispatch commands are documented here. The specific command structure is shown below.

tinkerforge call motion-detector-bricklet [<option>..] <uid> <function> [<argument>..]
Parameters:
  • <uid> -- string
  • <function> -- string

The call command is used to call a function of the Motion Detector Bricklet. It can take several options:

  • --help shows help for the specific call command and exits
  • --list-functions shows a list of known functions of the Motion Detector Bricklet and exits
tinkerforge dispatch motion-detector-bricklet [<option>..] <uid> <callback>
Parameters:
  • <uid> -- string
  • <callback> -- string

The dispatch command is used to dispatch a callback of the Motion Detector Bricklet. It can take several options:

  • --help shows help for the specific dispatch command and exits
  • --list-callbacks shows a list of known callbacks of the Motion Detector Bricklet and exits
tinkerforge call motion-detector-bricklet <uid> <function> [<option>..] [<argument>..]
Parameters:
  • <uid> -- string
  • <function> -- string

The <function> to be called can take different options depending of its kind. All functions can take the following options:

  • --help shows help for the specific function and exits

Getter functions can take the following options:

  • --execute <command> shell command line to execute for each incoming response (see section about output formatting for details)

Setter functions can take the following options:

  • --expect-response requests response and waits for it

The --expect-response option for setter functions allows to detect timeouts and other error conditions calls of setters as well. The device will then send a response for this purpose. If this option is not given for a setter function then no response is send and errors are silently ignored, because they cannot be detected.

tinkerforge dispatch motion-detector-bricklet <uid> <callback> [<option>..]
Parameters:
  • <uid> -- string
  • <callback> -- string

The <callback> to be dispatched can take several options:

  • --help shows help for the specific callback and exits
  • --execute <command> shell command line to execute for each incoming response (see section about output formatting for details)

Basic Functions

tinkerforge call motion-detector-bricklet <uid> get-motion-detected
Output:
  • motion -- int (has symbols)

Returns 1 if a motion was detected. How long this returns 1 after a motion was detected can be adjusted with one of the small potentiometers on the Motion Detector Bricklet, see here.

There is also a blue LED on the Bricklet that is on as long as the Bricklet is in the "motion detected" state.

The following symbols are available for this function:

  • not-detected = 0, for motion
  • detected = 1, for motion

Advanced Functions

tinkerforge call motion-detector-bricklet <uid> get-identity
Output:
  • uid -- string
  • connected-uid -- string
  • position -- char
  • hardware-version -- int,int,int
  • firmware-version -- int,int,int
  • device-identifier -- int (has symbols)

Returns the UID, the UID where the Bricklet is connected to, the position, the hardware and firmware version as well as the device identifier.

The position can be 'a', 'b', 'c' or 'd'.

The device identifier numbers can be found here

Callbacks

Callbacks can be used to receive time critical or recurring data from the device:

tinkerforge dispatch motion-detector-bricklet <uid> example

The available callbacks are described below.

Note

Using callbacks for recurring events is always preferred compared to using getters. It will use less USB bandwidth and the latency will be a lot better, since there is no round trip time.

tinkerforge dispatch motion-detector-bricklet <uid> motion-detected
Output:no output

This callback is called after a motion was detected.

tinkerforge dispatch motion-detector-bricklet <uid> detection-cycle-ended
Output:no output

This callback is called when the detection cycle ended. When this callback is called, a new motion can be detected again after approximately 2 seconds.

Creative Commons Licence The content of this page is licensed under Creative Commons Attribution 3.0 Unported License.