Shell - Line Bricklet¶

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 Line Bricklet

# Get current reflectivity
tinkerforge call line-bricklet $uid get-reflectivity

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 Line Bricklet

# Handle incoming reflectivity callbacks
tinkerforge dispatch line-bricklet $uid reflectivity &

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

# Get threshold callbacks with a debounce time of 1 second (1000ms)
tinkerforge call line-bricklet $uid set-debounce-period 1000

# Handle incoming reflectivity reached callbacks
tinkerforge dispatch line-bricklet $uid reflectivity-reached &

# Configure threshold for reflectivity "greater than 2000"
tinkerforge call line-bricklet $uid set-reflectivity-callback-threshold threshold-option-greater 2000 0

echo "Press key to exit"; read dummy

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

Command Structure¶

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

tinkerforge call line-bricklet [<option>..] <uid> <function> [<argument>..]¶

Parameters:	<uid> – Type: String <function> – Type: String

The call command is used to call a function of the Line 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 Line Bricklet and exits

tinkerforge dispatch line-bricklet [<option>..] <uid> <callback>¶

Parameters:	<uid> – Type: String <callback> – Type: String

The dispatch command is used to dispatch a callback of the Line 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 Line Bricklet and exits

tinkerforge call line-bricklet <uid> <function> [<option>..] [<argument>..]¶

Parameters:	<uid> – Type: String <function> – Type: 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 sent and errors are silently ignored, because they cannot be detected.

tinkerforge dispatch line-bricklet <uid> <callback> [<option>..]¶

Parameters:	<uid> – Type: String <callback> – Type: 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 line-bricklet <uid> get-reflectivity¶

Output:	reflectivity – Type: Int, Range: [0 to 212 - 1]

Returns the currently measured reflectivity. The reflectivity is a value between 0 (not reflective) and 4095 (very reflective).

Usually black has a low reflectivity while white has a high reflectivity.

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

Advanced Functions¶

tinkerforge call line-bricklet <uid> get-identity¶

Output:

uid – Type: String, Length: up to 8 connected-uid – Type: String, Length: up to 8 position – Type: Char, Range: [a to h, z] hardware-version – Type: Int Array, Length: 3 0: major – Type: Int, Range: [0 to 255] 1: minor – Type: Int, Range: [0 to 255] 2: revision – Type: Int, Range: [0 to 255] firmware-version – Type: Int Array, Length: 3 0: major – Type: Int, Range: [0 to 255] 1: minor – Type: Int, Range: [0 to 255] 2: revision – Type: Int, Range: [0 to 255] device-identifier – Type: Int, Range: [0 to 216 - 1]

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', 'd', 'e', 'f', 'g' or 'h' (Bricklet Port). A Bricklet connected to an Isolator Bricklet is always at position 'z'.

The device identifier numbers can be found here. 

Callback Configuration Functions¶

tinkerforge call line-bricklet <uid> set-reflectivity-callback-period <period>¶

Parameters:	<period> – Type: Int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
Output:	no output

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

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

tinkerforge call line-bricklet <uid> get-reflectivity-callback-period¶

Output:	period – Type: Int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

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

tinkerforge call line-bricklet <uid> set-reflectivity-callback-threshold <option> <min> <max>¶

Parameters:	<option> – Type: Char, Range: See symbols, Default: x <min> – Type: Int, Range: [0 to 216 - 1], Default: 0 <max> – Type: Int, Range: [0 to 216 - 1], Default: 0
Output:	no output

Sets the thresholds for the reflectivity-reached callback.

The following options are possible:

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

The following symbols are available for this function:

For <option>:

• threshold-option-off = x
• threshold-option-outside = o
• threshold-option-inside = i
• threshold-option-smaller = <
• threshold-option-greater = >

tinkerforge call line-bricklet <uid> get-reflectivity-callback-threshold¶

Output:	option – Type: Char, Range: See symbols, Default: x min – Type: Int, Range: [0 to 216 - 1], Default: 0 max – Type: Int, Range: [0 to 216 - 1], Default: 0

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

The following symbols are available for this function:

For option:

• threshold-option-off = x
• threshold-option-outside = o
• threshold-option-inside = i
• threshold-option-smaller = <
• threshold-option-greater = >

tinkerforge call line-bricklet <uid> set-debounce-period <debounce>¶

Parameters:	<debounce> – Type: Int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 100
Output:	no output

Sets the period with which the threshold callback

• reflectivity-reached

is triggered, if the threshold

• set-reflectivity-callback-threshold

keeps being reached.

tinkerforge call line-bricklet <uid> get-debounce-period¶

Output:	debounce – Type: Int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 100

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 line-bricklet <uid> example

The available callbacks are described below.

tinkerforge dispatch line-bricklet <uid> reflectivity¶

Output:	reflectivity – Type: Int, Range: [0 to 212 - 1]

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

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

tinkerforge dispatch line-bricklet <uid> reflectivity-reached¶

Output:	reflectivity – Type: Int, Range: [0 to 212 - 1]

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

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