Shell - Current25 Bricklet

This is the description of the Shell API bindings for the Current25 Bricklet. General information and technical specifications for the Current25 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 Current25 Bricklet

# Get current current
tinkerforge call current25-bricklet $uid get-current

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 Current25 Bricklet

# Handle incoming current callbacks
tinkerforge dispatch current25-bricklet $uid current &

# Set period for current callback to 1s (1000ms)
# Note: The current callback is only called every second
#       if the current has changed since the last call!
tinkerforge call current25-bricklet $uid set-current-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 Current25 Bricklet

# Get threshold callbacks with a debounce time of 10 seconds (10000ms)
tinkerforge call current25-bricklet $uid set-debounce-period 10000

# Handle incoming current reached callbacks
tinkerforge dispatch current25-bricklet $uid current-reached &

# Configure threshold for current "greater than 5 A"
tinkerforge call current25-bricklet $uid set-current-callback-threshold threshold-option-greater 5000 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 current25-bricklet [<option>..] <uid> <function> [<argument>..]
Parameters:
  • <uid> -- string
  • <function> -- string

The call command is used to call a function of the Current25 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 Current25 Bricklet and exits
tinkerforge dispatch current25-bricklet [<option>..] <uid> <callback>
Parameters:
  • <uid> -- string
  • <callback> -- string

The dispatch command is used to dispatch a callback of the Current25 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 Current25 Bricklet and exits
tinkerforge call current25-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 current25-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 current25-bricklet <uid> get-current
Output:
  • current -- int

Returns the current of the sensor. The value is in mA and between -25000mA and 25000mA.

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

Advanced Functions

tinkerforge call current25-bricklet <uid> calibrate
Output:no output

Calibrates the 0 value of the sensor. You have to call this function when there is no current present.

The zero point of the current sensor is depending on the exact properties of the analog-to-digital converter, the length of the Bricklet cable and the temperature. Thus, if you change the Brick or the environment in which the Bricklet is used, you might have to recalibrate.

The resulting calibration will be saved on the EEPROM of the Current Bricklet.

tinkerforge call current25-bricklet <uid> is-over-current
Output:
  • over -- bool

Returns true if more than 25A were measured.

Note

To reset this value you have to power cycle the Bricklet.

tinkerforge call current25-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-current 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.

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 current25-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 current25-bricklet <uid> set-current-callback-period <period>
Parameters:
  • <period> -- int
Output:

no output

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

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

The default value is 0.

tinkerforge call current25-bricklet <uid> get-current-callback-period
Output:
  • period -- int

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

tinkerforge call current25-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 current25-bricklet <uid> get-analog-value-callback-period
Output:
  • period -- int

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

tinkerforge call current25-bricklet <uid> set-current-callback-threshold <option> <min> <max>
Parameters:
  • <option> -- char (has symbols)
  • <min> -- int
  • <max> -- int
Output:

no output

Sets the thresholds for the current-reached callback.

The following options are possible:

Option Description
'x' Callback is turned off
'o' Callback is triggered when the current is outside the min and max values
'i' Callback is triggered when the current is inside the min and max values
'<' Callback is triggered when the current is smaller than the min value (max is ignored)
'>' Callback is triggered when the current 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 current25-bricklet <uid> get-current-callback-threshold
Output:
  • option -- char (has symbols)
  • min -- int
  • max -- int

Returns the threshold as set by set-current-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 current25-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 current25-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 current25-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 current25-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 current25-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 current25-bricklet <uid> current
Output:
  • current -- int

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

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

tinkerforge dispatch current25-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 sensor.

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

tinkerforge dispatch current25-bricklet <uid> current-reached
Output:
  • current -- int

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

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

tinkerforge dispatch current25-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 sensor.

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

tinkerforge dispatch current25-bricklet <uid> over-current
Output:no output

This callback is triggered when an over current is measured (see is-over-current).