This is the description of the Shell API bindings for the Joystick Bricklet. General information and technical specifications for the Joystick Bricklet 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 8 | #!/bin/sh
# connects to localhost:4223 by default, use --host and --port to change it
# change to your UID
uid=XYZ
# gt current position (x and y value)
tinkerforge call joystick-bricklet $uid get-position
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Download (example-callback.sh)
1 2 3 4 5 6 7 8 9 10 11 12 13 | #!/bin/sh
# connects to localhost:4223 by default, use --host and --port to change it
# change to your UID
uid=XYZ
# handle incoming pressed and released callbacks
# note: this chaining of two dispatches assumes that a pressed callback is
# always followed by a released callback
tinkerforge dispatch joystick-bricklet $uid pressed\
--execute "echo Pressed;
tinkerforge dispatch --duration exit-after-first joystick-bricklet $uid released\
--execute 'echo Released'"
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Download (example-find-corners.sh)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 | #!/bin/sh
# connects to localhost:4223 by default, use --host and --port to change it
# change to your UID
uid=XYZ
# get threshold callbacks with a debounce time of 0.2 seconds (200ms)
tinkerforge call joystick-bricklet $uid set-debounce-period 200
# configure threshold for "x or y value outside of [-99..99]"
tinkerforge call joystick-bricklet $uid set-position-callback-threshold outside -99 99 -99 99
# handle incoming position-reached callbacks
tinkerforge dispatch joystick-bricklet $uid position-reached\
--execute "if [ {y} -eq 100 ];
then echo Top;
elif [ {y} -eq -100 ];
then echo Bottom;
fi;
if [ {x} -eq 100 ];
then echo Right;
elif [ {x} -eq -100 ];
then echo Left;
fi"
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Possible exit codes for all tinkerforge commands are:
The common options of the call and dispatch commands are documented here. The specific command structure is shown below.
Parameters: |
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The call command is used to call a function of the Joystick Bricklet. It can take several options:
Parameters: |
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The dispatch command is used to dispatch a callback of the Joystick Bricklet. It can take several options:
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:
Getter functions can take the following options:
Setter functions can take the following options:
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.
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The <callback> to be dispatched can take several options:
Output: |
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Returns the position of the Joystick. The value ranges between -100 and 100 for both axis. The middle position of the joystick is x=0, y=0. The returned values are averaged and calibrated (see calibrate).
If you want to get the position periodically, it is recommended to use the callback position and set the period with set-position-callback-period.
Output: |
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Returns the values as read by a 12-bit analog-to-digital converter. The values are between 0 and 4095 for both axis.
Note
The values returned by get-position are 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 values periodically, it is recommended to use the callback analog-value and set the period with set-analog-value-callback-period.
Output: | no output |
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Calibrates the middle position of the Joystick. If your Joystick Bricklet does not return x=0 and y=0 in the middle position, call this function while the Joystick is standing still in the middle position.
The resulting calibration will be saved on the EEPROM of the Joystick Bricklet, thus you only have to calibrate it once.
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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' or 'd'.
The device identifier numbers can be found here.
Parameters: |
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Output: | no output |
Sets the period in ms with which the position callback is triggered periodically. A value of 0 turns the callback off.
position is only triggered if the position has changed since the last triggering.
The default value is 0.
Output: |
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Returns the period as set by set-position-callback-period.
Parameters: |
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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.
analog-value is only triggered if the analog values have changed since the last triggering.
The default value is 0.
Output: |
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Returns the period as set by set-analog-value-callback-period.
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Output: | no output |
Sets the thresholds for the position-reached callback.
The following options are possible:
Option | Description |
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'x' | Callback is turned off |
'o' | Callback is triggered when the position is outside the min and max values |
'i' | Callback is triggered when the position is inside the min and max values |
'<' | Callback is triggered when the position is smaller than the min values (max is ignored) |
'>' | Callback is triggered when the position is greater than the min values (max is ignored) |
The default value is ('x', 0, 0, 0, 0).
The following symbols are available for this function:
Output: |
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Returns the threshold as set by set-position-callback-threshold.
The following symbols are available for this function:
Parameters: |
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Output: | no output |
Sets the thresholds for the analog-value-reached callback.
The following options are possible:
Option | Description |
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'x' | Callback is turned off |
'o' | Callback is triggered when the analog values are outside the min and max values |
'i' | Callback is triggered when the analog values are inside the min and max values |
'<' | Callback is triggered when the analog values are smaller than the min values (max is ignored) |
'>' | Callback is triggered when the analog values are greater than the min values (max is ignored) |
The default value is ('x', 0, 0, 0, 0).
The following symbols are available for this function:
Output: |
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Returns the threshold as set by set-analog-value-callback-threshold.
The following symbols are available for this function:
Parameters: |
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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.
Output: |
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Returns the debounce period as set by set-debounce-period.
Callbacks can be used to receive time critical or recurring data from the device:
tinkerforge dispatch joystick-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.
Output: |
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This callback is triggered periodically with the period that is set by set-position-callback-period. The parameter is the position of the Joystick.
position is only triggered if the position has changed since the last triggering.
Output: |
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This callback is triggered periodically with the period that is set by set-analog-value-callback-period. The parameters are the analog values of the Joystick.
analog-value is only triggered if the values have changed since the last triggering.
Output: |
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This callback is triggered when the threshold as set by set-position-callback-threshold is reached. The parameters are the position of the Joystick.
If the threshold keeps being reached, the callback is triggered periodically with the period as set by set-debounce-period.
Output: |
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This callback is triggered when the threshold as set by set-analog-value-callback-threshold is reached. The parameters are the analog values of the Joystick.
If the threshold keeps being reached, the callback is triggered periodically with the period as set by set-debounce-period.
Output: | no output |
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This callback is triggered when the button is pressed.
Output: | no output |
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This callback is triggered when the button is released.