Shell - IO-4 Bricklet 2.0

This is the description of the Shell API bindings for the IO-4 Bricklet 2.0. General information and technical specifications for the IO-4 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).

Interrupt

Download (example-interrupt.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 IO-4 Bricklet 2.0

# Handle incoming input value callbacks
tinkerforge dispatch io4-v2-bricklet $uid input-value &

# Set period for input value (channel 1) callback to 0.5s (500ms)
tinkerforge call io4-v2-bricklet $uid set-input-value-callback-configuration 1 500 false

echo "Press key to exit"; read dummy

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

Output

Download (example-output.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 IO-4 Bricklet 2.0

# Configure channel 3 as output low
tinkerforge call io4-v2-bricklet $uid set-configuration 3 direction-out false

# Set channel 3 alternating high/low 10 times with 100 ms delay
for i in 0 1 2 3 4 5 6 7 8 9; do
    sleep 0.1
    tinkerforge call io4-v2-bricklet $uid set-selected-value 3 true
    sleep 0.1
    tinkerforge call io4-v2-bricklet $uid set-selected-value 3 false
done

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 io4-v2-bricklet [<option>..] <uid> <function> [<argument>..]
Parameters:
  • <uid> – Type: String
  • <function> – Type: String

The call command is used to call a function of the IO-4 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 IO-4 Bricklet 2.0 and exits
tinkerforge dispatch io4-v2-bricklet [<option>..] <uid> <callback>
Parameters:
  • <uid> – Type: String
  • <callback> – Type: String

The dispatch command is used to dispatch a callback of the IO-4 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 IO-4 Bricklet 2.0 and exits
tinkerforge call io4-v2-bricklet <uid> <function> [<option>..] [<argument>..]
Parameters:
  • <uid> – Type: String
  • <function> – Type: 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 sent and errors are silently ignored, because they cannot be detected.

tinkerforge dispatch io4-v2-bricklet <uid> <callback> [<option>..]
Parameters:
  • <uid> – Type: String
  • <callback> – Type: 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 io4-v2-bricklet <uid> set-value <value>
Parameters:
  • <value> – Type: Bool Array, Length: 4
Output:
  • no output

Sets the output value of all four channels. A value of true or false outputs logic 1 or logic 0 respectively on the corresponding channel.

Use set-selected-value to change only one output channel state.

For example: (True, True, False, False) will turn the channels 0-1 high and the channels 2-3 low.

All running monoflop timers and PWMs will be aborted if this function is called.

Note

This function does nothing for channels that are configured as input. Pull-up resistors can be switched on with set-configuration.

tinkerforge call io4-v2-bricklet <uid> get-value
Output:
  • value – Type: Bool Array, Length: 4

Returns the logic levels that are currently measured on the channels. This function works if the channel is configured as input as well as if it is configured as output.

tinkerforge call io4-v2-bricklet <uid> set-selected-value <channel> <value>
Parameters:
  • <channel> – Type: Int, Range: [0 to 3]
  • <value> – Type: Bool
Output:
  • no output

Sets the output value of a specific channel without affecting the other channels.

A running monoflop timer or PWM for the specific channel will be aborted if this function is called.

Note

This function does nothing for channels that are configured as input. Pull-up resistors can be switched on with set-configuration.

tinkerforge call io4-v2-bricklet <uid> set-configuration <channel> <direction> <value>
Parameters:
  • <channel> – Type: Int, Range: [0 to 3]
  • <direction> – Type: Char, Range: See symbols, Default: i
  • <value> – Type: Bool, Default: true
Output:
  • no output

Configures the value and direction of a specific channel. Possible directions are 'i' and 'o' for input and output.

If the direction is configured as output, the value is either high or low (set as true or false).

If the direction is configured as input, the value is either pull-up or default (set as true or false).

For example:

  • (0, 'i', true) will set channel 0 as input pull-up.
  • (1, 'i', false) will set channel 1 as input default (floating if nothing is connected).
  • (2, 'o', true) will set channel 2 as output high.
  • (3, 'o', false) will set channel 3 as output low.

A running monoflop timer or PWM for the specific channel will be aborted if this function is called.

The following symbols are available for this function:

For <direction>:

  • direction-in = i
  • direction-out = o
tinkerforge call io4-v2-bricklet <uid> get-configuration <channel>
Parameters:
  • <channel> – Type: Int, Range: [0 to 3]
Output:
  • direction – Type: Char, Range: See symbols, Default: i
  • value – Type: Bool, Default: true

Returns the channel configuration as set by set-configuration.

The following symbols are available for this function:

For direction:

  • direction-in = i
  • direction-out = o

Advanced Functions

tinkerforge call io4-v2-bricklet <uid> set-monoflop <channel> <value> <time>
Parameters:
  • <channel> – Type: Int, Range: [0 to 3]
  • <value> – Type: Bool
  • <time> – Type: Int, Unit: 1 ms, Range: [0 to 232 - 1]
Output:
  • no output

The first parameter is the desired state of the channel (true means output high and false means output low). The second parameter indicates the time that the channel should hold the state.

If this function is called with the parameters (true, 1500): The channel will turn on and in 1.5s it will turn off again.

A PWM for the selected channel will be aborted if this function is called.

A monoflop can be used as a failsafe mechanism. For example: Lets assume you have a RS485 bus and a IO-4 Bricklet 2.0 is connected to one of the slave stacks. You can now call this function every second, with a time parameter of two seconds. The channel will be high all the time. If now the RS485 connection is lost, the channel will turn low in at most two seconds.

tinkerforge call io4-v2-bricklet <uid> get-monoflop <channel>
Parameters:
  • <channel> – Type: Int, Range: [0 to 3]
Output:
  • value – Type: Bool
  • time – Type: Int, Unit: 1 ms, Range: [0 to 232 - 1]
  • time-remaining – Type: Int, Unit: 1 ms, Range: [0 to 232 - 1]

Returns (for the given channel) the current value and the time as set by set-monoflop as well as the remaining time until the value flips.

If the timer is not running currently, the remaining time will be returned as 0.

tinkerforge call io4-v2-bricklet <uid> get-edge-count <channel> <reset-counter>
Parameters:
  • <channel> – Type: Int, Range: [0 to 3]
  • <reset-counter> – Type: Bool
Output:
  • count – Type: Int, Range: [0 to 232 - 1]

Returns the current value of the edge counter for the selected channel. You can configure the edges that are counted with set-edge-count-configuration.

If you set the reset counter to true, the count is set back to 0 directly after it is read.

Note

Calling this function is only allowed for channels configured as input.

tinkerforge call io4-v2-bricklet <uid> set-edge-count-configuration <channel> <edge-type> <debounce>
Parameters:
  • <channel> – Type: Int, Range: [0 to 3]
  • <edge-type> – Type: Int, Range: See symbols, Default: 0
  • <debounce> – Type: Int, Unit: 1 ms, Range: [0 to 255], Default: 100
Output:
  • no output

Configures the edge counter for a specific channel.

The edge type parameter configures if rising edges, falling edges or both are counted if the channel is configured for input. Possible edge types are:

  • 0 = rising
  • 1 = falling
  • 2 = both

Configuring an edge counter resets its value to 0.

If you don't know what any of this means, just leave it at default. The default configuration is very likely OK for you.

Note

Calling this function is only allowed for channels configured as input.

The following symbols are available for this function:

For <edge-type>:

  • edge-type-rising = 0
  • edge-type-falling = 1
  • edge-type-both = 2
tinkerforge call io4-v2-bricklet <uid> get-edge-count-configuration <channel>
Parameters:
  • <channel> – Type: Int, Range: [0 to 3]
Output:
  • edge-type – Type: Int, Range: See symbols, Default: 0
  • debounce – Type: Int, Unit: 1 ms, Range: [0 to 255], Default: 100

Returns the edge type and debounce time for the selected channel as set by set-edge-count-configuration.

Note

Calling this function is only allowed for channels configured as input.

The following symbols are available for this function:

For edge-type:

  • edge-type-rising = 0
  • edge-type-falling = 1
  • edge-type-both = 2
tinkerforge call io4-v2-bricklet <uid> set-pwm-configuration <channel> <frequency> <duty-cycle>
Parameters:
  • <channel> – Type: Int, Range: [0 to 3]
  • <frequency> – Type: Int, Unit: 1/10 Hz, Range: [0 to 320000000], Default: 0
  • <duty-cycle> – Type: Int, Unit: 1/100 %, Range: [0 to 10000], Default: 0
Output:
  • no output

Activates a PWM for the given channel.

You need to set the channel to output before you call this function, otherwise it will report an invalid parameter error. To turn the PWM off again, you can set the frequency to 0 or any other function that changes a value of the channel (e.g. set-selected-value).

A running monoflop timer for the given channel will be aborted if this function is called.

tinkerforge call io4-v2-bricklet <uid> get-pwm-configuration <channel>
Parameters:
  • <channel> – Type: Int, Range: [0 to 3]
Output:
  • frequency – Type: Int, Unit: 1/10 Hz, Range: [0 to 320000000], Default: 0
  • duty-cycle – Type: Int, Unit: 1/100 %, Range: [0 to 10000], Default: 0

Returns the PWM configuration as set by set-pwm-configuration.

tinkerforge call io4-v2-bricklet <uid> get-spitfp-error-count
Output:
  • error-count-ack-checksum – Type: Int, Range: [0 to 232 - 1]
  • error-count-message-checksum – Type: Int, Range: [0 to 232 - 1]
  • error-count-frame – Type: Int, Range: [0 to 232 - 1]
  • error-count-overflow – Type: Int, Range: [0 to 232 - 1]

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 io4-v2-bricklet <uid> set-status-led-config <config>
Parameters:
  • <config> – Type: Int, Range: See symbols, Default: 3
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:

For <config>:

  • status-led-config-off = 0
  • status-led-config-on = 1
  • status-led-config-show-heartbeat = 2
  • status-led-config-show-status = 3
tinkerforge call io4-v2-bricklet <uid> get-status-led-config
Output:
  • config – Type: Int, Range: See symbols, Default: 3

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

The following symbols are available for this function:

For config:

  • status-led-config-off = 0
  • status-led-config-on = 1
  • status-led-config-show-heartbeat = 2
  • status-led-config-show-status = 3
tinkerforge call io4-v2-bricklet <uid> get-chip-temperature
Output:
  • temperature – Type: Int, Unit: 1 °C, Range: [-215 to 215 - 1]

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.

tinkerforge call io4-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 io4-v2-bricklet <uid> get-identity
Output:
  • uid – Type: String, Length: up to 8
  • connected-uid – Type: String, Length: up to 8
  • position – Type: Char, Range: [a to h, z]
  • hardware-version – Type: Int Array, Length: 3
    • 0: major – Type: Int, Range: [0 to 255]
    • 1: minor – Type: Int, Range: [0 to 255]
    • 2: revision – Type: Int, Range: [0 to 255]
  • firmware-version – Type: Int Array, Length: 3
    • 0: major – Type: Int, Range: [0 to 255]
    • 1: minor – Type: Int, Range: [0 to 255]
    • 2: revision – Type: Int, Range: [0 to 255]
  • device-identifier – Type: Int, Range: [0 to 216 - 1]

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

Callback Configuration Functions

tinkerforge call io4-v2-bricklet <uid> set-input-value-callback-configuration <channel> <period> <value-has-to-change>
Parameters:
  • <channel> – Type: Int, Range: [0 to 3]
  • <period> – Type: Int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • <value-has-to-change> – Type: Bool, Default: false
Output:
  • no output

This callback can be configured per channel.

The period is the period with which the input-value 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.

tinkerforge call io4-v2-bricklet <uid> get-input-value-callback-configuration <channel>
Parameters:
  • <channel> – Type: Int, Range: [0 to 3]
Output:
  • period – Type: Int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • value-has-to-change – Type: Bool, Default: false

Returns the callback configuration for the given channel as set by set-input-value-callback-configuration.

tinkerforge call io4-v2-bricklet <uid> set-all-input-value-callback-configuration <period> <value-has-to-change>
Parameters:
  • <period> – Type: Int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • <value-has-to-change> – Type: Bool, Default: false
Output:
  • no output

The period is the period with which the all-input-value 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.

tinkerforge call io4-v2-bricklet <uid> get-all-input-value-callback-configuration
Output:
  • period – Type: Int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • value-has-to-change – Type: Bool, Default: false

Returns the callback configuration as set by set-all-input-value-callback-configuration.

Callbacks

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

tinkerforge dispatch io4-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 io4-v2-bricklet <uid> input-value
Output:
  • channel – Type: Int, Range: [0 to 3]
  • changed – Type: Bool
  • value – Type: Bool

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

The parameters are the channel, a value-changed indicator and the actual value for the channel. The changed parameter is true if the value has changed since the last callback.

tinkerforge dispatch io4-v2-bricklet <uid> all-input-value
Output:
  • changed – Type: Bool Array, Length: 4
  • value – Type: Bool Array, Length: 4

This callback is triggered periodically according to the configuration set by set-all-input-value-callback-configuration.

The parameters are the same as get-value. Additional the changed parameter is true if the value has changed since the last callback.

tinkerforge dispatch io4-v2-bricklet <uid> monoflop-done
Output:
  • channel – Type: Int, Range: [0 to 3]
  • value – Type: Bool

This callback is triggered whenever a monoflop timer reaches 0. The parameters contain the channel and the current value of the channel (the value after the monoflop).

Internal Functions

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.

tinkerforge call io4-v2-bricklet <uid> set-bootloader-mode <mode>
Parameters:
  • <mode> – Type: Int, Range: See symbols
Output:
  • status – Type: Int, Range: See 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:

For <mode>:

  • bootloader-mode-bootloader = 0
  • bootloader-mode-firmware = 1
  • bootloader-mode-bootloader-wait-for-reboot = 2
  • bootloader-mode-firmware-wait-for-reboot = 3
  • bootloader-mode-firmware-wait-for-erase-and-reboot = 4

For status:

  • bootloader-status-ok = 0
  • bootloader-status-invalid-mode = 1
  • bootloader-status-no-change = 2
  • bootloader-status-entry-function-not-present = 3
  • bootloader-status-device-identifier-incorrect = 4
  • bootloader-status-crc-mismatch = 5
tinkerforge call io4-v2-bricklet <uid> get-bootloader-mode
Output:
  • mode – Type: Int, Range: See symbols

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

The following symbols are available for this function:

For mode:

  • bootloader-mode-bootloader = 0
  • bootloader-mode-firmware = 1
  • bootloader-mode-bootloader-wait-for-reboot = 2
  • bootloader-mode-firmware-wait-for-reboot = 3
  • bootloader-mode-firmware-wait-for-erase-and-reboot = 4
tinkerforge call io4-v2-bricklet <uid> set-write-firmware-pointer <pointer>
Parameters:
  • <pointer> – Type: Int, Unit: 1 B, Range: [0 to 232 - 1]
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 io4-v2-bricklet <uid> write-firmware <data>
Parameters:
  • <data> – Type: Int Array, Length: 64, Range: [0 to 255]
Output:
  • status – Type: Int, Range: [0 to 255]

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 io4-v2-bricklet <uid> write-uid <uid>
Parameters:
  • <uid> – Type: Int, Range: [0 to 232 - 1]
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 io4-v2-bricklet <uid> read-uid
Output:
  • uid – Type: Int, Range: [0 to 232 - 1]

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