Shell - Accelerometer Bricklet 2.0

This is the description of the Shell API bindings for the Accelerometer Bricklet 2.0. General information and technical specifications for the Accelerometer Bricklet 2.0 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 Accelerometer Bricklet 2.0

# Get current acceleration
tinkerforge call accelerometer-v2-bricklet $uid get-acceleration

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 Accelerometer Bricklet 2.0

# Handle incoming acceleration callbacks
tinkerforge dispatch accelerometer-v2-bricklet $uid acceleration &

# Set period for acceleration callback to 1s (1000ms)
tinkerforge call accelerometer-v2-bricklet $uid set-acceleration-callback-configuration 1000 false

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-v2-bricklet [<option>..] <uid> <function> [<argument>..]
Parameters:
  • <uid> -- string
  • <function> -- string

The call command is used to call a function of the Accelerometer Bricklet 2.0. 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 2.0 and exits
tinkerforge dispatch accelerometer-v2-bricklet [<option>..] <uid> <callback>
Parameters:
  • <uid> -- string
  • <callback> -- string

The dispatch command is used to dispatch a callback of the Accelerometer Bricklet 2.0. 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 2.0 and exits
tinkerforge call accelerometer-v2-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-v2-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-v2-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/10000 (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-configuration.

tinkerforge call accelerometer-v2-bricklet <uid> set-configuration <data-rate> <full-scale>
Parameters:
  • <data-rate> -- int (has symbols)
  • <full-scale> -- int (has symbols)
Output:

no output

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

  • Data rate of 0.781Hz to 25600Hz.
  • Full scale range of ±2g up to ±8g.

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

The default values are 100Hz data rate and ±2g range.

The following symbols are available for this function:

  • data-rate-0-781hz = 0, for <data-rate>
  • data-rate-1-563hz = 1, for <data-rate>
  • data-rate-3-125hz = 2, for <data-rate>
  • data-rate-6-2512hz = 3, for <data-rate>
  • data-rate-12-5hz = 4, for <data-rate>
  • data-rate-25hz = 5, for <data-rate>
  • data-rate-50hz = 6, for <data-rate>
  • data-rate-100hz = 7, for <data-rate>
  • data-rate-200hz = 8, for <data-rate>
  • data-rate-400hz = 9, for <data-rate>
  • data-rate-800hz = 10, for <data-rate>
  • data-rate-1600hz = 11, for <data-rate>
  • data-rate-3200hz = 12, for <data-rate>
  • data-rate-6400hz = 13, for <data-rate>
  • data-rate-12800hz = 14, for <data-rate>
  • data-rate-25600hz = 15, for <data-rate>
  • full-scale-2g = 0, for <full-scale>
  • full-scale-4g = 1, for <full-scale>
  • full-scale-8g = 2, for <full-scale>
tinkerforge call accelerometer-v2-bricklet <uid> get-configuration
Output:
  • data-rate -- int (has symbols)
  • full-scale -- int (has symbols)

Returns the configuration as set by set-configuration.

The following symbols are available for this function:

  • data-rate-0-781hz = 0, for data-rate
  • data-rate-1-563hz = 1, for data-rate
  • data-rate-3-125hz = 2, for data-rate
  • data-rate-6-2512hz = 3, for data-rate
  • data-rate-12-5hz = 4, for data-rate
  • data-rate-25hz = 5, for data-rate
  • data-rate-50hz = 6, for data-rate
  • data-rate-100hz = 7, for data-rate
  • data-rate-200hz = 8, for data-rate
  • data-rate-400hz = 9, for data-rate
  • data-rate-800hz = 10, for data-rate
  • data-rate-1600hz = 11, for data-rate
  • data-rate-3200hz = 12, for data-rate
  • data-rate-6400hz = 13, for data-rate
  • data-rate-12800hz = 14, for data-rate
  • data-rate-25600hz = 15, for data-rate
  • full-scale-2g = 0, for full-scale
  • full-scale-4g = 1, for full-scale
  • full-scale-8g = 2, for full-scale
tinkerforge call accelerometer-v2-bricklet <uid> set-info-led-config <config>
Parameters:
  • <config> -- int (has symbols)
Output:

no output

Configures the info LED (marked as "Force" on the Bricklet) to be either turned off, turned on, or blink in heartbeat mode.

The following symbols are available for this function:

  • info-led-config-off = 0, for <config>
  • info-led-config-on = 1, for <config>
  • info-led-config-show-heartbeat = 2, for <config>
tinkerforge call accelerometer-v2-bricklet <uid> get-info-led-config
Output:
  • config -- int (has symbols)

Returns the LED configuration as set by set-info-led-config

The following symbols are available for this function:

  • info-led-config-off = 0, for config
  • info-led-config-on = 1, for config
  • info-led-config-show-heartbeat = 2, for config
tinkerforge call accelerometer-v2-bricklet <uid> set-continuous-acceleration-configuration <enable-x> <enable-y> <enable-z> <resolution>
Parameters:
  • <enable-x> -- bool
  • <enable-y> -- bool
  • <enable-z> -- bool
  • <resolution> -- int (has symbols)
Output:

no output

For high throughput of acceleration data (> 1000Hz) you have to use the continuous-acceleration-16-bit or continuous-acceleration-8-bit callbacks.

You can enable the callback for each axis (x, y, z) individually and choose a resolution of 8 bit or 16 bit.

If at least one of the axis is enabled and the resolution is set to 8 bit, the continuous-acceleration-8-bit callback is activated. If at least one of the axis is enabled and the resolution is set to 16 bit, the continuous-acceleration-16-bit callback is activated.

The returned values are raw ADC data. If you want to put this data into a FFT to determine the occurrences of specific frequencies we recommend that you use the data as is. It has all of the ADC noise in it. This noise looks like pure noise at first glance, but it might still have some frequnecy information in it that can be utilized by the FFT.

Otherwise you have to use the following formulas that depend on the configured resolution (8/16 bit) and the full scale range (see set-configuration) to calculate the data in g/10000 (same unit that is returned by get-acceleration):

  • 16 bit, full scale 2G: acceleration = value*625/1024
  • 16 bit, full scale 4G: acceleration = value*1250/1024
  • 16 bit, full scale 8G: acceleration = value*2500/1024

If a resolution of 8 bit is used, only the 8 most significant bits will be transferred, so you can use the following formulas:

  • 8 bit, full scale 2G: acceleration = value*256*625/1024
  • 8 bit, full scale 4G: acceleration = value*256*1250/1024
  • 8 bit, full scale 8G: acceleration = value*256*2500/1024

If no axis is enabled, both callbacks are disabled. If one of the continuous callbacks is enabled, the acceleration callback is disabled.

The maximum throughput depends on the exact configuration:

Number of axis enabled Throughput 8 bit Throughout 16 bit
1 25600Hz 25600Hz
2 25600Hz 15000Hz
3 20000Hz 10000Hz

The following symbols are available for this function:

  • resolution-8bit = 0, for <resolution>
  • resolution-16bit = 1, for <resolution>
tinkerforge call accelerometer-v2-bricklet <uid> get-continuous-acceleration-configuration
Output:
  • enable-x -- bool
  • enable-y -- bool
  • enable-z -- bool
  • resolution -- int (has symbols)

Returns the continuous acceleration configuration as set by set-continuous-acceleration-configuration.

The following symbols are available for this function:

  • resolution-8bit = 0, for resolution
  • resolution-16bit = 1, for resolution

Advanced Functions

tinkerforge call accelerometer-v2-bricklet <uid> set-filter-configuration <iir-bypass> <low-pass-filter>
Parameters:
  • <iir-bypass> -- int (has symbols)
  • <low-pass-filter> -- int (has symbols)
Output:

no output

Configures IIR Bypass filter mode and low pass filter roll off corner frequency.

The filter can be applied or bypassed and the corner frequency can be half or a ninth of the output data rate.

Accelerometer filter

By default filtering is applied and the filter corner frequency is a ninth of the output data rate.

The following symbols are available for this function:

  • iir-bypass-applied = 0, for <iir-bypass>
  • iir-bypass-bypassed = 1, for <iir-bypass>
  • low-pass-filter-ninth = 0, for <low-pass-filter>
  • low-pass-filter-half = 1, for <low-pass-filter>

New in version 2.0.2 (Plugin).

tinkerforge call accelerometer-v2-bricklet <uid> get-filter-configuration
Output:
  • iir-bypass -- int (has symbols)
  • low-pass-filter -- int (has symbols)

Returns the configuration as set by set-filter-configuration.

The following symbols are available for this function:

  • iir-bypass-applied = 0, for iir-bypass
  • iir-bypass-bypassed = 1, for iir-bypass
  • low-pass-filter-ninth = 0, for low-pass-filter
  • low-pass-filter-half = 1, for low-pass-filter

New in version 2.0.2 (Plugin).

tinkerforge call accelerometer-v2-bricklet <uid> get-spitfp-error-count
Output:
  • error-count-ack-checksum -- int
  • error-count-message-checksum -- int
  • error-count-frame -- int
  • error-count-overflow -- int

Returns the error count for the communication between Brick and Bricklet.

The errors are divided into

  • ACK checksum errors,
  • message checksum errors,
  • framing errors and
  • overflow errors.

The errors counts are for errors that occur on the Bricklet side. All Bricks have a similar function that returns the errors on the Brick side.

tinkerforge call accelerometer-v2-bricklet <uid> set-bootloader-mode <mode>
Parameters:
  • <mode> -- int (has symbols)
Output:
  • status -- int (has symbols)

Sets the bootloader mode and returns the status after the requested mode change was instigated.

You can change from bootloader mode to firmware mode and vice versa. A change from bootloader mode to firmware mode will only take place if the entry function, device identifier and CRC are present and correct.

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

The following symbols are available for this function:

  • bootloader-mode-bootloader = 0, for <mode>
  • bootloader-mode-firmware = 1, for <mode>
  • bootloader-mode-bootloader-wait-for-reboot = 2, for <mode>
  • bootloader-mode-firmware-wait-for-reboot = 3, for <mode>
  • bootloader-mode-firmware-wait-for-erase-and-reboot = 4, for <mode>
  • bootloader-status-ok = 0, for status
  • bootloader-status-invalid-mode = 1, for status
  • bootloader-status-no-change = 2, for status
  • bootloader-status-entry-function-not-present = 3, for status
  • bootloader-status-device-identifier-incorrect = 4, for status
  • bootloader-status-crc-mismatch = 5, for status
tinkerforge call accelerometer-v2-bricklet <uid> get-bootloader-mode
Output:
  • mode -- int (has symbols)

Returns the current bootloader mode, see set-bootloader-mode.

The following symbols are available for this function:

  • bootloader-mode-bootloader = 0, for mode
  • bootloader-mode-firmware = 1, for mode
  • bootloader-mode-bootloader-wait-for-reboot = 2, for mode
  • bootloader-mode-firmware-wait-for-reboot = 3, for mode
  • bootloader-mode-firmware-wait-for-erase-and-reboot = 4, for mode
tinkerforge call accelerometer-v2-bricklet <uid> set-write-firmware-pointer <pointer>
Parameters:
  • <pointer> -- int
Output:

no output

Sets the firmware pointer for write-firmware. The pointer has to be increased by chunks of size 64. The data is written to flash every 4 chunks (which equals to one page of size 256).

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

tinkerforge call accelerometer-v2-bricklet <uid> write-firmware <data>
Parameters:
  • <data> -- int,int,..61x..,int
Output:
  • status -- int

Writes 64 Bytes of firmware at the position as written by set-write-firmware-pointer before. The firmware is written to flash every 4 chunks.

You can only write firmware in bootloader mode.

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

tinkerforge call accelerometer-v2-bricklet <uid> set-status-led-config <config>
Parameters:
  • <config> -- int (has symbols)
Output:

no output

Sets the status LED configuration. By default the LED shows communication traffic between Brick and Bricklet, it flickers once for every 10 received data packets.

You can also turn the LED permanently on/off or show a heartbeat.

If the Bricklet is in bootloader mode, the LED is will show heartbeat by default.

The following symbols are available for this function:

  • status-led-config-off = 0, for <config>
  • status-led-config-on = 1, for <config>
  • status-led-config-show-heartbeat = 2, for <config>
  • status-led-config-show-status = 3, for <config>
tinkerforge call accelerometer-v2-bricklet <uid> get-status-led-config
Output:
  • config -- int (has symbols)

Returns the configuration as set by set-status-led-config

The following symbols are available for this function:

  • status-led-config-off = 0, for config
  • status-led-config-on = 1, for config
  • status-led-config-show-heartbeat = 2, for config
  • status-led-config-show-status = 3, for config
tinkerforge call accelerometer-v2-bricklet <uid> get-chip-temperature
Output:
  • temperature -- int

Returns the temperature in °C as measured inside the microcontroller. The value returned is not the ambient temperature!

The temperature is only proportional to the real temperature and it has bad accuracy. Practically it is only useful as an indicator for temperature changes.

tinkerforge call accelerometer-v2-bricklet <uid> reset
Output:no output

Calling this function will reset the Bricklet. All configurations will be lost.

After a reset you have to create new device objects, calling functions on the existing ones will result in undefined behavior!

tinkerforge call accelerometer-v2-bricklet <uid> write-uid <uid>
Parameters:
  • <uid> -- int
Output:

no output

Writes a new UID into flash. If you want to set a new UID you have to decode the Base58 encoded UID string into an integer first.

We recommend that you use Brick Viewer to change the UID.

tinkerforge call accelerometer-v2-bricklet <uid> read-uid
Output:
  • uid -- int

Returns the current UID as an integer. Encode as Base58 to get the usual string version.

tinkerforge call accelerometer-v2-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-v2-bricklet <uid> set-acceleration-callback-configuration <period> <value-has-to-change>
Parameters:
  • <period> -- int
  • <value-has-to-change> -- bool
Output:

no output

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

If the value has to change-parameter is set to true, the callback is only triggered after the value has changed. If the value didn't change within the period, the callback is triggered immediately on change.

If it is set to false, the callback is continuously triggered with the period, independent of the value.

If this callback is enabled, the continuous-acceleration-16-bit callback and continuous-acceleration-8-bit callback will automatically be disabled.

The default value is (0, false).

tinkerforge call accelerometer-v2-bricklet <uid> get-acceleration-callback-configuration
Output:
  • period -- int
  • value-has-to-change -- bool

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

Callbacks

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

tinkerforge dispatch accelerometer-v2-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-v2-bricklet <uid> acceleration
Output:
  • x -- int
  • y -- int
  • z -- int

This callback is triggered periodically according to the configuration set by set-acceleration-callback-configuration.

The parameters are the same as get-acceleration.

tinkerforge dispatch accelerometer-v2-bricklet <uid> continuous-acceleration-16-bit
Output:
  • acceleration -- int,int,..27x..,int

Returns 30 acceleration values with 16 bit resolution. The data rate can be configured with set-configuration and this callback can be enabled with set-continuous-acceleration-configuration.

The returned values are raw ADC data. If you want to put this data into a FFT to determine the occurrences of specific frequencies we recommend that you use the data as is. It has all of the ADC noise in it. This noise looks like pure noise at first glance, but it might still have some frequnecy information in it that can be utilized by the FFT.

Otherwise you have to use the following formulas that depend on the full scale range (see set-configuration) to calculate the data in g/10000 (same unit that is returned by get-acceleration):

  • Full scale 2G: acceleration = value*625/1024
  • Full scale 4G: acceleration = value*1250/1024
  • Full scale 8G: acceleration = value*2500/1024

The data is formated in the sequence "x, y, z, x, y, z, ..." depending on the enabled axis. Examples:

  • x, y, z enabled: "x, y, z, ... 10x ..., x, y, z"
  • x, z enabled: "x, z, ... 15x ..., x, z"
  • y enabled: "y, ... 30x ..., y"
tinkerforge dispatch accelerometer-v2-bricklet <uid> continuous-acceleration-8-bit
Output:
  • acceleration -- int,int,..57x..,int

Returns 30 acceleration values with 8 bit resolution. The data rate can be configured with set-configuration and this callback can be enabled with set-continuous-acceleration-configuration.

The returned values are raw ADC data. If you want to put this data into a FFT to determine the occurrences of specific frequencies we recommend that you use the data as is. It has all of the ADC noise in it. This noise looks like pure noise at first glance, but it might still have some frequnecy information in it that can be utilized by the FFT.

Otherwise you have to use the following formulas that depend on the full scale range (see set-configuration) to calculate the data in g/10000 (same unit that is returned by get-acceleration):

  • Full scale 2G: acceleration = value*256*625/1024
  • Full scale 4G: acceleration = value*256*1250/1024
  • Full scale 8G: acceleration = value*256*2500/1024

The data is formated in the sequence "x, y, z, x, y, z, ..." depending on the enabled axis. Examples:

  • x, y, z enabled: "x, y, z, ... 20x ..., x, y, z"
  • x, z enabled: "x, z, ... 30x ..., x, z"
  • y enabled: "y, ... 60x ..., y"