Shell - Accelerometer Bricklet

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

1
2
3
4
5
6
7
#!/bin/sh
# Connects to localhost:4223 by default, use --host and --port to change this

uid=XYZ # Change XYZ to the UID of your Accelerometer Bricklet

# Get current acceleration
tinkerforge call accelerometer-bricklet $uid get-acceleration

Callback

Download (example-callback.sh)

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
#!/bin/sh
# Connects to localhost:4223 by default, use --host and --port to change this

uid=XYZ # Change XYZ to the UID of your Accelerometer Bricklet

# Handle incoming acceleration callbacks
tinkerforge dispatch accelerometer-bricklet $uid acceleration &

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

echo "Press key to exit"; read dummy

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

Threshold

Download (example-threshold.sh)

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
#!/bin/sh
# Connects to localhost:4223 by default, use --host and --port to change this

uid=XYZ # Change XYZ to the UID of your Accelerometer Bricklet

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

# Handle incoming acceleration reached callbacks
tinkerforge dispatch accelerometer-bricklet $uid acceleration-reached &

# Configure threshold for acceleration "greater than 2 g, 2 g, 2 g"
tinkerforge call accelerometer-bricklet $uid set-acceleration-callback-threshold threshold-option-greater 2000 0 2000 0 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 accelerometer-bricklet [<option>..] <uid> <function> [<argument>..]
Parameters:
  • <uid> -- string
  • <function> -- string

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

The dispatch command is used to dispatch a callback of the Accelerometer 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 Accelerometer Bricklet and exits
tinkerforge call accelerometer-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 accelerometer-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 accelerometer-bricklet <uid> get-acceleration
Output:
  • x -- int
  • y -- int
  • z -- int

Returns the acceleration in x, y and z direction. The values are given in g/1000 (1g = 9.80665m/s²), not to be confused with grams.

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

tinkerforge call accelerometer-bricklet <uid> get-temperature
Output:
  • temperature -- int

Returns the temperature of the accelerometer in °C.

tinkerforge call accelerometer-bricklet <uid> led-on
Output:no output

Enables the LED on the Bricklet.

tinkerforge call accelerometer-bricklet <uid> led-off
Output:no output

Disables the LED on the Bricklet.

tinkerforge call accelerometer-bricklet <uid> is-led-on
Output:
  • on -- bool

Returns true if the LED is enabled, false otherwise.

Advanced Functions

tinkerforge call accelerometer-bricklet <uid> set-configuration <data-rate> <full-scale> <filter-bandwidth>
Parameters:
  • <data-rate> -- int (has symbols)
  • <full-scale> -- int (has symbols)
  • <filter-bandwidth> -- int (has symbols)
Output:

no output

Configures the data rate, full scale range and filter bandwidth. Possible values are:

  • Data rate of 0Hz to 1600Hz.
  • Full scale range of -2G to +2G up to -16G to +16G.
  • Filter bandwidth between 50Hz and 800Hz.

Decreasing data rate or full scale range will also decrease the noise on the data.

The default values are 100Hz data rate, -4G to +4G range and 200Hz filter bandwidth.

The following symbols are available for this function:

  • data-rate-off = 0, for <data-rate>
  • data-rate-3hz = 1, for <data-rate>
  • data-rate-6hz = 2, for <data-rate>
  • data-rate-12hz = 3, for <data-rate>
  • data-rate-25hz = 4, for <data-rate>
  • data-rate-50hz = 5, for <data-rate>
  • data-rate-100hz = 6, for <data-rate>
  • data-rate-400hz = 7, for <data-rate>
  • data-rate-800hz = 8, for <data-rate>
  • data-rate-1600hz = 9, for <data-rate>
  • full-scale-2g = 0, for <full-scale>
  • full-scale-4g = 1, for <full-scale>
  • full-scale-6g = 2, for <full-scale>
  • full-scale-8g = 3, for <full-scale>
  • full-scale-16g = 4, for <full-scale>
  • filter-bandwidth-800hz = 0, for <filter-bandwidth>
  • filter-bandwidth-400hz = 1, for <filter-bandwidth>
  • filter-bandwidth-200hz = 2, for <filter-bandwidth>
  • filter-bandwidth-50hz = 3, for <filter-bandwidth>
tinkerforge call accelerometer-bricklet <uid> get-configuration
Output:
  • data-rate -- int (has symbols)
  • full-scale -- int (has symbols)
  • filter-bandwidth -- int (has symbols)

Returns the configuration as set by set-configuration.

The following symbols are available for this function:

  • data-rate-off = 0, for data-rate
  • data-rate-3hz = 1, for data-rate
  • data-rate-6hz = 2, for data-rate
  • data-rate-12hz = 3, for data-rate
  • data-rate-25hz = 4, for data-rate
  • data-rate-50hz = 5, for data-rate
  • data-rate-100hz = 6, for data-rate
  • data-rate-400hz = 7, for data-rate
  • data-rate-800hz = 8, for data-rate
  • data-rate-1600hz = 9, for data-rate
  • full-scale-2g = 0, for full-scale
  • full-scale-4g = 1, for full-scale
  • full-scale-6g = 2, for full-scale
  • full-scale-8g = 3, for full-scale
  • full-scale-16g = 4, for full-scale
  • filter-bandwidth-800hz = 0, for filter-bandwidth
  • filter-bandwidth-400hz = 1, for filter-bandwidth
  • filter-bandwidth-200hz = 2, for filter-bandwidth
  • filter-bandwidth-50hz = 3, for filter-bandwidth
tinkerforge call accelerometer-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 accelerometer-bricklet <uid> set-acceleration-callback-period <period>
Parameters:
  • <period> -- int
Output:

no output

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

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

The default value is 0.

tinkerforge call accelerometer-bricklet <uid> get-acceleration-callback-period
Output:
  • period -- int

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

tinkerforge call accelerometer-bricklet <uid> set-acceleration-callback-threshold <option> <min-x> <max-x> <min-y> <max-y> <min-z> <max-z>
Parameters:
  • <option> -- char (has symbols)
  • <min-x> -- int
  • <max-x> -- int
  • <min-y> -- int
  • <max-y> -- int
  • <min-z> -- int
  • <max-z> -- int
Output:

no output

Sets the thresholds for the acceleration-reached callback.

The following options are possible:

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

The default value is ('x', 0, 0, 0, 0, 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 accelerometer-bricklet <uid> get-acceleration-callback-threshold
Output:
  • option -- char (has symbols)
  • min-x -- int
  • max-x -- int
  • min-y -- int
  • max-y -- int
  • min-z -- int
  • max-z -- int

Returns the threshold as set by set-acceleration-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 accelerometer-bricklet <uid> set-debounce-period <debounce>
Parameters:
  • <debounce> -- int
Output:

no output

Sets the period in ms with which the threshold callback

is triggered, if the threshold

keeps being reached.

The default value is 100.

tinkerforge call accelerometer-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 accelerometer-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 accelerometer-bricklet <uid> acceleration
Output:
  • x -- int
  • y -- int
  • z -- int

This callback is triggered periodically with the period that is set by set-acceleration-callback-period. The parameters are the X, Y and Z acceleration.

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

tinkerforge dispatch accelerometer-bricklet <uid> acceleration-reached
Output:
  • x -- int
  • y -- int
  • z -- int

This callback is triggered when the threshold as set by set-acceleration-callback-threshold is reached. The parameters are the X, Y and Z acceleration.

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