This is the description of the Shell API bindings for the Multi Touch Bricklet 2.0. General information and technical specifications for the Multi Touch Bricklet 2.0 are summarized in its hardware description.
An installation guide for the Shell API bindings is part of their general description.
The example code below is Public Domain (CC0 1.0).
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 Multi Touch Bricklet 2.0
# Get current touch state
tinkerforge call multi-touch-v2-bricklet $uid get-touch-state
|
Download (example-callback.sh)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 | #!/bin/sh
# Connects to localhost:4223 by default, use --host and --port to change this
uid=XYZ # Change XYZ to the UID of your Multi Touch Bricklet 2.0
# Handle incoming touch state callbacks
tinkerforge dispatch multi-touch-v2-bricklet $uid touch-state &
# Set period for touch state callback to 0.01s (10ms)
tinkerforge call multi-touch-v2-bricklet $uid set-touch-state-callback-configuration 10 true
echo "Press key to exit"; read dummy
kill -- -$$ # Stop callback dispatch in background
|
Possible exit codes for all tinkerforge
commands are:
argparse
module is missingThe common options of the call
and dispatch
commands are documented
here. The specific command structure is shown below.
call
multi-touch-v2-bricklet
[<option>..] <uid> <function> [<argument>..]¶Parameters: |
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The call
command is used to call a function of the Multi Touch 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 Multi Touch Bricklet 2.0 and exitsdispatch
multi-touch-v2-bricklet
[<option>..] <uid> <callback>¶Parameters: |
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The dispatch
command is used to dispatch a callback of the Multi Touch 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 Multi Touch Bricklet 2.0 and exitsmulti-touch-v2-bricklet
<uid> <function>
[<option>..] [<argument>..]¶Parameters: |
|
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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 exitsGetter 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 itThe --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.
multi-touch-v2-bricklet
<uid> <callback>
[<option>..]¶Parameters: |
|
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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)multi-touch-v2-bricklet
<uid> get-touch-state
¶Output: |
|
---|
Returns the current touch state. The state is given as a array of bools.
Element 0 to 11 represent the 12 electrodes and element 12 represents the proximity.
If an electrode is touched, the corresponding element is true. If a hand or similar is in proximity to the electrodes, element 12 is true.
The proximity is activated with a distance of 1-2cm. An electrode is already counted as touched if a finger is nearly touching the electrode. This means that you can put a piece of paper or foil or similar on top of a electrode to build a touch panel with a professional look.
If you want to get the value periodically, it is recommended to use the
touch-state
callback. You can set the callback configuration
with set-touch-state-callback-configuration
.
multi-touch-v2-bricklet
<uid> recalibrate
¶Output: |
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Recalibrates the electrodes. Call this function whenever you changed or moved you electrodes.
multi-touch-v2-bricklet
<uid> set-electrode-config
<enabled-electrodes>¶Parameters: |
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Output: |
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Enables/disables electrodes with a bool array (see get-touch-state
).
True enables the electrode, false disables the electrode. A disabled electrode will always return false as its state. If you don't need all electrodes you can disable the electrodes that are not needed.
It is recommended that you disable the proximity electrode (element 12) if
the proximity feature is not needed. This will reduce the amount of
traffic that is produced by the touch-state
callback.
Disabling electrodes will also reduce power consumption.
multi-touch-v2-bricklet
<uid> get-electrode-config
¶Output: |
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Returns the electrode configuration, as set by set-electrode-config
.
multi-touch-v2-bricklet
<uid> set-electrode-sensitivity
<sensitivity>¶Parameters: |
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Output: |
|
Sets the sensitivity of the electrodes. An electrode with a high sensitivity will register a touch earlier then an electrode with a low sensitivity.
If you build a big electrode you might need to decrease the sensitivity, since the area that can be charged will get bigger. If you want to be able to activate an electrode from further away you need to increase the sensitivity.
After a new sensitivity is set, you likely want to call recalibrate
to calibrate the electrodes with the newly defined sensitivity.
multi-touch-v2-bricklet
<uid> get-electrode-sensitivity
¶Output: |
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Returns the current sensitivity, as set by set-electrode-sensitivity
.
multi-touch-v2-bricklet
<uid> set-touch-led-config
<config>¶Parameters: |
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Output: |
|
Configures the touch LED to be either turned off, turned on, blink in heartbeat mode or show the touch state (electrode touched = LED on).
The following symbols are available for this function:
For <config>:
multi-touch-v2-bricklet
<uid> get-touch-led-config
¶Output: |
|
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Returns the LED configuration as set by set-touch-led-config
The following symbols are available for this function:
For config:
multi-touch-v2-bricklet
<uid> get-spitfp-error-count
¶Output: |
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Returns the error count for the communication between Brick and Bricklet.
The errors are divided into
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.
multi-touch-v2-bricklet
<uid> set-status-led-config
<config>¶Parameters: |
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Output: |
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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:
For <config>:
multi-touch-v2-bricklet
<uid> get-status-led-config
¶Output: |
|
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Returns the configuration as set by set-status-led-config
The following symbols are available for this function:
For config:
multi-touch-v2-bricklet
<uid> get-chip-temperature
¶Output: |
|
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Returns the temperature 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.
multi-touch-v2-bricklet
<uid> reset
¶Output: |
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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!
multi-touch-v2-bricklet
<uid> get-identity
¶Output: |
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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.
multi-touch-v2-bricklet
<uid> set-touch-state-callback-configuration
<period> <value-has-to-change>¶Parameters: |
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Output: |
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The period is the period with which the touch-state
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.
multi-touch-v2-bricklet
<uid> get-touch-state-callback-configuration
¶Output: |
|
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Returns the callback configuration as set by
set-touch-state-callback-configuration
.
Callbacks can be used to receive time critical or recurring data from the device:
tinkerforge dispatch multi-touch-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.
multi-touch-v2-bricklet
<uid> touch-state
¶Output: |
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Returns the current touch state, see get-touch-state
for
information about the state.
This callback is triggered every time the touch state changes with
a given period (see set-touch-state-callback-configuration
)
Internal functions are used for maintenance tasks such as flashing a new firmware of changing the UID of a Bricklet. These task should be performed using Brick Viewer instead of using the internal functions directly.
multi-touch-v2-bricklet
<uid> set-bootloader-mode
<mode>¶Parameters: |
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Output: |
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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:
For <mode>:
For status:
multi-touch-v2-bricklet
<uid> get-bootloader-mode
¶Output: |
|
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Returns the current bootloader mode, see set-bootloader-mode
.
The following symbols are available for this function:
For mode:
multi-touch-v2-bricklet
<uid> set-write-firmware-pointer
<pointer>¶Parameters: |
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Output: |
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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.
multi-touch-v2-bricklet
<uid> write-firmware
<data>¶Parameters: |
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Output: |
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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.
multi-touch-v2-bricklet
<uid> write-uid
<uid>¶Parameters: |
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Output: |
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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.
multi-touch-v2-bricklet
<uid> read-uid
¶Output: |
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Returns the current UID as an integer. Encode as Base58 to get the usual string version.