Shell - CO2 Bricklet 2.0

This is the description of the Shell API bindings for the CO2 Bricklet 2.0. General information and technical specifications for the CO2 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 CO2 Bricklet 2.0

# Get current all values
tinkerforge call co2-v2-bricklet $uid get-all-values

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 CO2 Bricklet 2.0

# Handle incoming all values callbacks
tinkerforge dispatch co2-v2-bricklet $uid all-values &

# Set period for all values callback to 1s (1000ms)
tinkerforge call co2-v2-bricklet $uid set-all-values-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 co2-v2-bricklet [<option>..] <uid> <function> [<argument>..]
Parameters:
  • <uid> -- string
  • <function> -- string

The call command is used to call a function of the CO2 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 CO2 Bricklet 2.0 and exits
tinkerforge dispatch co2-v2-bricklet [<option>..] <uid> <callback>
Parameters:
  • <uid> -- string
  • <callback> -- string

The dispatch command is used to dispatch a callback of the CO2 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 CO2 Bricklet 2.0 and exits
tinkerforge call co2-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 co2-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 co2-v2-bricklet <uid> get-all-values
Output:
  • co2-concentration -- int
  • temperature -- int
  • humidity -- int

Returns all values measured by the CO2 Bricklet 2.0. The values are CO2 concentration (in ppm), temperature (in 0.01 °C) and humidity (in 0.01 %RH).

If you want to get the values periodically, it is recommended to use the all-values callback. You can set the callback configuration with set-all-values-callback-configuration.

tinkerforge call co2-v2-bricklet <uid> set-air-pressure <air-pressure>
Parameters:
  • <air-pressure> -- int
Output:

no output

The CO2 concentration (among other things) depends on the ambient air pressure.

To increase the accuracy of the CO2 Bricklet 2.0 you can set the current air pressure. You use the Barometer Bricklet 2.0 or the Air Quality Bricklet to get the current air pressure.

The expected unit of the ambient air pressure value is mbar.

By default air pressure compensation is disabled. Once you set a value it will be used for compensation. You can turn the compensation off again by setting the value to 0.

It is sufficient to update the value every few minutes.

tinkerforge call co2-v2-bricklet <uid> get-air-pressure
Output:
  • air-pressure -- int

Returns the ambient air pressure as set by set-air-pressure.

tinkerforge call co2-v2-bricklet <uid> set-temperature-offset <offset>
Parameters:
  • <offset> -- int
Output:

no output

Sets a temperature offset with resolution 1/100°C. A offset of 10 will decrease the measured temperature by 0.1°C.

If you install this Bricklet into an enclosure and you want to measure the ambient temperature, you may have to decrease the measured temperature by some value to compensate for the error because of the heating inside of the enclosure.

We recommend that you leave the parts in the enclosure running for at least 24 hours such that a temperature equilibrium can be reached. After that you can measure the temperature directly outside of enclosure and set the difference as offset.

This temperature offset is used to calculate the relative humidity and CO2 concentration. In case the Bricklet is installed in an enclosure, we recommend to measure and set the temperature offset to improve the accuracy of the measurements.

It is sufficient to set the temperature offset once. The offset is saved in non-volatile memory and is applied again after a power loss.

tinkerforge call co2-v2-bricklet <uid> get-temperature-offset
Output:
  • offset -- int

Returns the temperature offset as set by set-temperature-offset.

tinkerforge call co2-v2-bricklet <uid> get-co2-concentration
Output:
  • co2-concentration -- int

Returns CO2 concentration in ppm.

If you want to get the value periodically, it is recommended to use the co2-concentration callback. You can set the callback configuration with set-co2-concentration-callback-configuration.

tinkerforge call co2-v2-bricklet <uid> get-temperature
Output:
  • temperature -- int

Returns temperature in steps of 0.01 °C.

If you want to get the value periodically, it is recommended to use the temperature callback. You can set the callback configuration with set-temperature-callback-configuration.

tinkerforge call co2-v2-bricklet <uid> get-humidity
Output:
  • humidity -- int

Returns relative humidity in steps of 0.01 %RH.

If you want to get the value periodically, it is recommended to use the humidity callback. You can set the callback configuration with set-humidity-callback-configuration.

Advanced Functions

tinkerforge call co2-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 co2-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 co2-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 co2-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 co2-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 co2-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 co2-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 co2-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 co2-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 co2-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 co2-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 co2-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 co2-v2-bricklet <uid> set-all-values-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 all-values 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 at least one of the values has changed. If the values 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.

The default value is (0, false).

tinkerforge call co2-v2-bricklet <uid> get-all-values-callback-configuration
Output:
  • period -- int
  • value-has-to-change -- bool

Returns the callback configuration as set by set-all-values-callback-configuration.

tinkerforge call co2-v2-bricklet <uid> set-co2-concentration-callback-configuration <period> <value-has-to-change> <option> <min> <max>
Parameters:
  • <period> -- int
  • <value-has-to-change> -- bool
  • <option> -- char (has symbols)
  • <min> -- int
  • <max> -- int
Output:

no output

The period in ms is the period with which the co2-concentration 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.

It is furthermore possible to constrain the callback with thresholds.

The option-parameter together with min/max sets a threshold for the co2-concentration callback.

The following options are possible:

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

If the option is set to 'x' (threshold turned off) the callback is triggered with the fixed period.

The default value is (0, false, 'x', 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 co2-v2-bricklet <uid> get-co2-concentration-callback-configuration
Output:
  • period -- int
  • value-has-to-change -- bool
  • option -- char (has symbols)
  • min -- int
  • max -- int

Returns the callback configuration as set by set-co2-concentration-callback-configuration.

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 co2-v2-bricklet <uid> set-temperature-callback-configuration <period> <value-has-to-change> <option> <min> <max>
Parameters:
  • <period> -- int
  • <value-has-to-change> -- bool
  • <option> -- char (has symbols)
  • <min> -- int
  • <max> -- int
Output:

no output

The period in ms is the period with which the temperature 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.

It is furthermore possible to constrain the callback with thresholds.

The option-parameter together with min/max sets a threshold for the temperature callback.

The following options are possible:

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

If the option is set to 'x' (threshold turned off) the callback is triggered with the fixed period.

The default value is (0, false, 'x', 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 co2-v2-bricklet <uid> get-temperature-callback-configuration
Output:
  • period -- int
  • value-has-to-change -- bool
  • option -- char (has symbols)
  • min -- int
  • max -- int

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

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 co2-v2-bricklet <uid> set-humidity-callback-configuration <period> <value-has-to-change> <option> <min> <max>
Parameters:
  • <period> -- int
  • <value-has-to-change> -- bool
  • <option> -- char (has symbols)
  • <min> -- int
  • <max> -- int
Output:

no output

The period in ms is the period with which the humidity 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.

It is furthermore possible to constrain the callback with thresholds.

The option-parameter together with min/max sets a threshold for the humidity callback.

The following options are possible:

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

If the option is set to 'x' (threshold turned off) the callback is triggered with the fixed period.

The default value is (0, false, 'x', 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 co2-v2-bricklet <uid> get-humidity-callback-configuration
Output:
  • period -- int
  • value-has-to-change -- bool
  • option -- char (has symbols)
  • min -- int
  • max -- int

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

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

Callbacks

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

tinkerforge dispatch co2-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 co2-v2-bricklet <uid> all-values
Output:
  • co2-concentration -- int
  • temperature -- int
  • humidity -- int

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

The parameters are the same as get-all-values.

tinkerforge dispatch co2-v2-bricklet <uid> co2-concentration
Output:
  • co2-concentration -- int

This callback is triggered periodically according to the configuration set by set-co2-concentration-callback-configuration.

The parameter is the same as get-co2-concentration.

tinkerforge dispatch co2-v2-bricklet <uid> temperature
Output:
  • temperature -- int

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

The parameter is the same as get-temperature.

tinkerforge dispatch co2-v2-bricklet <uid> humidity
Output:
  • humidity -- int

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

The parameter is the same as get-humidity.