Shell - Ambient Light Bricklet

This is the description of the Shell API bindings for the Ambient Light Bricklet. General information and technical specifications for the Ambient Light 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).

Simple

Download (example-simple.sh)

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

uid=XYZ # Change XYZ to the UID of your Ambient Light Bricklet

# Get current illuminance
tinkerforge call ambient-light-bricklet $uid get-illuminance

Callback

Download (example-callback.sh)

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

uid=XYZ # Change XYZ to the UID of your Ambient Light Bricklet

# Handle incoming illuminance callbacks
tinkerforge dispatch ambient-light-bricklet $uid illuminance &

# Set period for illuminance callback to 1s (1000ms)
# Note: The illuminance callback is only called every second
#       if the illuminance has changed since the last call!
tinkerforge call ambient-light-bricklet $uid set-illuminance-callback-period 1000

echo "Press key to exit"; read dummy

kill -- -$$ # Stop callback dispatch in background

Threshold

Download (example-threshold.sh)

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

uid=XYZ # Change XYZ to the UID of your Ambient Light Bricklet

# Get threshold callbacks with a debounce time of 10 seconds (10000ms)
tinkerforge call ambient-light-bricklet $uid set-debounce-period 10000

# Handle incoming illuminance reached callbacks
tinkerforge dispatch ambient-light-bricklet $uid illuminance-reached\
 --execute "echo Illuminance: {illuminance}/10 lx. Too bright, close the curtains!" &

# Configure threshold for illuminance "greater than 200 lx"
tinkerforge call ambient-light-bricklet $uid set-illuminance-callback-threshold threshold-option-greater 2000 0

echo "Press key to exit"; read dummy

kill -- -$$ # Stop callback dispatch in background

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 ambient-light-bricklet [<option>..] <uid> <function> [<argument>..]
Parameters:
  • <uid> -- string
  • <function> -- string

The call command is used to call a function of the Ambient Light 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 Ambient Light Bricklet and exits
tinkerforge dispatch ambient-light-bricklet [<option>..] <uid> <callback>
Parameters:
  • <uid> -- string
  • <callback> -- string

The dispatch command is used to dispatch a callback of the Ambient Light 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 Ambient Light Bricklet and exits
tinkerforge call ambient-light-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 ambient-light-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 ambient-light-bricklet <uid> get-illuminance
Output:
  • illuminance -- int

Returns the illuminance of the ambient light sensor. The value has a range of 0 to 9000 and is given in lux/10, i.e. a value of 4500 means that an illuminance of 450lux is measured.

If you want to get the illuminance periodically, it is recommended to use the illuminance callback and set the period with set-illuminance-callback-period.

Advanced Functions

tinkerforge call ambient-light-bricklet <uid> get-analog-value
Output:
  • value -- int

Returns the value as read by a 12-bit analog-to-digital converter. The value is between 0 and 4095.

Note

The value returned by get-illuminance is averaged over several samples to yield less noise, while get-analog-value gives back raw unfiltered analog values. The only reason to use get-analog-value is, if you need the full resolution of the analog-to-digital converter.

Also, the analog-to-digital converter covers three different ranges that are set dynamically depending on the light intensity. It is impossible to distinguish between these ranges with the analog value.

If you want the analog value periodically, it is recommended to use the analog-value callback and set the period with set-analog-value-callback-period.

tinkerforge call ambient-light-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

Callback Configuration Functions

tinkerforge call ambient-light-bricklet <uid> set-illuminance-callback-period <period>
Parameters:
  • <period> -- int
Output:

no output

Sets the period in ms with which the illuminance callback is triggered periodically. A value of 0 turns the callback off.

The illuminance callback is only triggered if the illuminance has changed since the last triggering.

The default value is 0.

tinkerforge call ambient-light-bricklet <uid> get-illuminance-callback-period
Output:
  • period -- int

Returns the period as set by set-illuminance-callback-period.

tinkerforge call ambient-light-bricklet <uid> set-analog-value-callback-period <period>
Parameters:
  • <period> -- int
Output:

no output

Sets the period in ms with which the analog-value callback is triggered periodically. A value of 0 turns the callback off.

The analog-value callback is only triggered if the analog value has changed since the last triggering.

The default value is 0.

tinkerforge call ambient-light-bricklet <uid> get-analog-value-callback-period
Output:
  • period -- int

Returns the period as set by set-analog-value-callback-period.

tinkerforge call ambient-light-bricklet <uid> set-illuminance-callback-threshold <option> <min> <max>
Parameters:
  • <option> -- char (has symbols)
  • <min> -- int
  • <max> -- int
Output:

no output

Sets the thresholds for the illuminance-reached callback.

The following options are possible:

Option Description
'x' Callback is turned off
'o' Callback is triggered when the illuminance is outside the min and max values
'i' Callback is triggered when the illuminance is inside the min and max values
'<' Callback is triggered when the illuminance is smaller than the min value (max is ignored)
'>' Callback is triggered when the illuminance is greater than the min value (max is ignored)

The default value is ('x', 0, 0).

The following symbols are available for this function:

  • threshold-option-off = x, for <option>
  • threshold-option-outside = o, for <option>
  • threshold-option-inside = i, for <option>
  • threshold-option-smaller = <, for <option>
  • threshold-option-greater = >, for <option>
tinkerforge call ambient-light-bricklet <uid> get-illuminance-callback-threshold
Output:
  • option -- char (has symbols)
  • min -- int
  • max -- int

Returns the threshold as set by set-illuminance-callback-threshold.

The following symbols are available for this function:

  • threshold-option-off = x, for option
  • threshold-option-outside = o, for option
  • threshold-option-inside = i, for option
  • threshold-option-smaller = <, for option
  • threshold-option-greater = >, for option
tinkerforge call ambient-light-bricklet <uid> set-analog-value-callback-threshold <option> <min> <max>
Parameters:
  • <option> -- char (has symbols)
  • <min> -- int
  • <max> -- int
Output:

no output

Sets the thresholds for the analog-value-reached callback.

The following options are possible:

Option Description
'x' Callback is turned off
'o' Callback is triggered when the analog value is outside the min and max values
'i' Callback is triggered when the analog value is inside the min and max values
'<' Callback is triggered when the analog value is smaller than the min value (max is ignored)
'>' Callback is triggered when the analog value is greater than the min value (max is ignored)

The default value is ('x', 0, 0).

The following symbols are available for this function:

  • threshold-option-off = x, for <option>
  • threshold-option-outside = o, for <option>
  • threshold-option-inside = i, for <option>
  • threshold-option-smaller = <, for <option>
  • threshold-option-greater = >, for <option>
tinkerforge call ambient-light-bricklet <uid> get-analog-value-callback-threshold
Output:
  • option -- char (has symbols)
  • min -- int
  • max -- int

Returns the threshold as set by set-analog-value-callback-threshold.

The following symbols are available for this function:

  • threshold-option-off = x, for option
  • threshold-option-outside = o, for option
  • threshold-option-inside = i, for option
  • threshold-option-smaller = <, for option
  • threshold-option-greater = >, for option
tinkerforge call ambient-light-bricklet <uid> set-debounce-period <debounce>
Parameters:
  • <debounce> -- int
Output:

no output

Sets the period in ms with which the threshold callbacks

are triggered, if the thresholds

keep being reached.

The default value is 100.

tinkerforge call ambient-light-bricklet <uid> get-debounce-period
Output:
  • debounce -- int

Returns the debounce period as set by set-debounce-period.

Callbacks

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

tinkerforge dispatch ambient-light-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 ambient-light-bricklet <uid> illuminance
Output:
  • illuminance -- int

This callback is triggered periodically with the period that is set by set-illuminance-callback-period. The parameter is the illuminance of the ambient light sensor.

The illuminance callback is only triggered if the illuminance has changed since the last triggering.

tinkerforge dispatch ambient-light-bricklet <uid> analog-value
Output:
  • value -- int

This callback is triggered periodically with the period that is set by set-analog-value-callback-period. The parameter is the analog value of the ambient light sensor.

The analog-value callback is only triggered if the analog value has changed since the last triggering.

tinkerforge dispatch ambient-light-bricklet <uid> illuminance-reached
Output:
  • illuminance -- int

This callback is triggered when the threshold as set by set-illuminance-callback-threshold is reached. The parameter is the illuminance of the ambient light sensor.

If the threshold keeps being reached, the callback is triggered periodically with the period as set by set-debounce-period.

tinkerforge dispatch ambient-light-bricklet <uid> analog-value-reached
Output:
  • value -- int

This callback is triggered when the threshold as set by set-analog-value-callback-threshold is reached. The parameter is the analog value of the ambient light sensor.

If the threshold keeps being reached, the callback is triggered periodically with the period as set by set-debounce-period.