Modbus - Humidity Bricklet 2.0

This is the description of the Modbus protocol for the Humidity Bricklet 2.0. General information and technical specifications for the Humidity Bricklet 2.0 are summarized in its hardware description.

API

A general description of the Modbus protocol structure can be found here.

Basic Functions

BrickletHumidityV2.get_humidity
Function ID:
  • 1
Request:
  • empty payload
Response:
  • humidity – Type: uint16, Unit: 1/100 %, Range: [0 to 10000]

Returns the humidity measured by the sensor.

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

BrickletHumidityV2.get_temperature
Function ID:
  • 5
Request:
  • empty payload
Response:
  • temperature – Type: int16, Unit: 1/100 °C, Range: [-4000 to 16500]

Returns the temperature measured by the sensor.

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

BrickletHumidityV2.set_heater_configuration
Function ID:
  • 9
Request:
  • heater_config – Type: uint8, Range: See meanings, Default: False
Response:
  • no response

Enables/disables the heater. The heater can be used to dry the sensor in extremely wet conditions.

The following meanings are defined for the elements of this function:

For heater_config:

  • 0 = Disabled
  • 1 = Enabled
BrickletHumidityV2.get_heater_configuration
Function ID:
  • 10
Request:
  • empty payload
Response:
  • heater_config – Type: uint8, Range: See meanings, Default: False

Returns the heater configuration as set by set_heater_configuration.

The following meanings are defined for the elements of this function:

For heater_config:

  • 0 = Disabled
  • 1 = Enabled
BrickletHumidityV2.set_moving_average_configuration
Function ID:
  • 11
Request:
  • moving_average_length_humidity – Type: uint16, Range: [1 to 1000], Default: 5
  • moving_average_length_temperature – Type: uint16, Range: [1 to 1000], Default: 5
Response:
  • no response

Sets the length of a moving averaging for the humidity and temperature.

Setting the length to 1 will turn the averaging off. With less averaging, there is more noise on the data.

New data is gathered every 50ms*. With a moving average of length 1000 the resulting averaging window has a length of 50s. If you want to do long term measurements the longest moving average will give the cleanest results.

* In firmware version 2.0.3 we added the set_samples_per_second function. It configures the measurement frequency. Since high frequencies can result in self-heating of th IC, changed the default value from 20 samples per second to 1. With 1 sample per second a moving average length of 1000 would result in an averaging window of 1000 seconds!

BrickletHumidityV2.get_moving_average_configuration
Function ID:
  • 12
Request:
  • empty payload
Response:
  • moving_average_length_humidity – Type: uint16, Range: [1 to 1000], Default: 5
  • moving_average_length_temperature – Type: uint16, Range: [1 to 1000], Default: 5

Returns the moving average configuration as set by set_moving_average_configuration.

BrickletHumidityV2.set_samples_per_second
Function ID:
  • 13
Request:
  • sps – Type: uint8, Range: See meanings, Default: 3
Response:
  • no response

Sets the samples per second that are gathered by the humidity/temperature sensor HDC1080.

We added this function since we found out that a high measurement frequency can lead to self-heating of the sensor. Which can distort the temperature measurement.

If you don't need a lot of measurements, you can use the lowest available measurement frequency of 0.1 samples per second for the least amount of self-heating.

Before version 2.0.3 the default was 20 samples per second. The new default is 1 sample per second.

New in version 2.0.3 (Plugin).

The following meanings are defined for the elements of this function:

For sps:

  • 0 = 20
  • 1 = 10
  • 2 = 5
  • 3 = 1
  • 4 = 02
  • 5 = 01
BrickletHumidityV2.get_samples_per_second
Function ID:
  • 14
Request:
  • empty payload
Response:
  • sps – Type: uint8, Range: See meanings, Default: 3

Returnes the samples per second, as set by set_samples_per_second.

New in version 2.0.3 (Plugin).

The following meanings are defined for the elements of this function:

For sps:

  • 0 = 20
  • 1 = 10
  • 2 = 5
  • 3 = 1
  • 4 = 02
  • 5 = 01

Advanced Functions

BrickletHumidityV2.get_spitfp_error_count
Function ID:
  • 234
Request:
  • empty payload
Response:
  • error_count_ack_checksum – Type: uint32, Range: [0 to 232 - 1]
  • error_count_message_checksum – Type: uint32, Range: [0 to 232 - 1]
  • error_count_frame – Type: uint32, Range: [0 to 232 - 1]
  • error_count_overflow – Type: uint32, 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.

BrickletHumidityV2.set_status_led_config
Function ID:
  • 239
Request:
  • config – Type: uint8, Range: See meanings, Default: 3
Response:
  • no response

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 meanings are defined for the elements of this function:

For config:

  • 0 = Off
  • 1 = On
  • 2 = Show Heartbeat
  • 3 = Show Status
BrickletHumidityV2.get_status_led_config
Function ID:
  • 240
Request:
  • empty payload
Response:
  • config – Type: uint8, Range: See meanings, Default: 3

Returns the configuration as set by set_status_led_config

The following meanings are defined for the elements of this function:

For config:

  • 0 = Off
  • 1 = On
  • 2 = Show Heartbeat
  • 3 = Show Status
BrickletHumidityV2.get_chip_temperature
Function ID:
  • 242
Request:
  • empty payload
Response:
  • temperature – Type: int16, 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.

BrickletHumidityV2.reset
Function ID:
  • 243
Request:
  • empty payload
Response:
  • no response

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!

BrickletHumidityV2.get_identity
Function ID:
  • 255
Request:
  • empty payload
Response:
  • uid – Type: char[8]
  • connected_uid – Type: char[8]
  • position – Type: char, Range: ['a' to 'h', 'z']
  • hardware_version – Type: uint8[3]
    • 0: major – Type: uint8, Range: [0 to 255]
    • 1: minor – Type: uint8, Range: [0 to 255]
    • 2: revision – Type: uint8, Range: [0 to 255]
  • firmware_version – Type: uint8[3]
    • 0: major – Type: uint8, Range: [0 to 255]
    • 1: minor – Type: uint8, Range: [0 to 255]
    • 2: revision – Type: uint8, Range: [0 to 255]
  • device_identifier – Type: uint16, 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

BrickletHumidityV2.set_humidity_callback_configuration
Function ID:
  • 2
Request:
  • period – Type: uint32, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • value_has_to_change – Type: bool, Default: false
  • option – Type: char, Range: See meanings, Default: 'x'
  • min – Type: uint16, Unit: 1/100 %, Range: [0 to 216 - 1], Default: 0
  • max – Type: uint16, Unit: 1/100 %, Range: [0 to 216 - 1], Default: 0
Response:
  • no response

The period is the period with which the CALLBACK_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 CALLBACK_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 following meanings are defined for the elements of this function:

For option:

  • 'x' = Off
  • 'o' = Outside
  • 'i' = Inside
  • '<' = Smaller
  • '>' = Greater
BrickletHumidityV2.get_humidity_callback_configuration
Function ID:
  • 3
Request:
  • empty payload
Response:
  • period – Type: uint32, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • value_has_to_change – Type: bool, Default: false
  • option – Type: char, Range: See meanings, Default: 'x'
  • min – Type: uint16, Unit: 1/100 %, Range: [0 to 216 - 1], Default: 0
  • max – Type: uint16, Unit: 1/100 %, Range: [0 to 216 - 1], Default: 0

Returns the callback configuration as set by set_humidity_callback_configuration.

The following meanings are defined for the elements of this function:

For option:

  • 'x' = Off
  • 'o' = Outside
  • 'i' = Inside
  • '<' = Smaller
  • '>' = Greater
BrickletHumidityV2.set_temperature_callback_configuration
Function ID:
  • 6
Request:
  • period – Type: uint32, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • value_has_to_change – Type: bool, Default: false
  • option – Type: char, Range: See meanings, Default: 'x'
  • min – Type: int16, Unit: 1/100 °C, Range: [-215 to 215 - 1], Default: 0
  • max – Type: int16, Unit: 1/100 °C, Range: [-215 to 215 - 1], Default: 0
Response:
  • no response

The period is the period with which the CALLBACK_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 CALLBACK_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 following meanings are defined for the elements of this function:

For option:

  • 'x' = Off
  • 'o' = Outside
  • 'i' = Inside
  • '<' = Smaller
  • '>' = Greater
BrickletHumidityV2.get_temperature_callback_configuration
Function ID:
  • 7
Request:
  • empty payload
Response:
  • period – Type: uint32, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • value_has_to_change – Type: bool, Default: false
  • option – Type: char, Range: See meanings, Default: 'x'
  • min – Type: int16, Unit: 1/100 °C, Range: [-215 to 215 - 1], Default: 0
  • max – Type: int16, Unit: 1/100 °C, Range: [-215 to 215 - 1], Default: 0

Returns the callback configuration as set by set_temperature_callback_configuration.

The following meanings are defined for the elements of this function:

For option:

  • 'x' = Off
  • 'o' = Outside
  • 'i' = Inside
  • '<' = Smaller
  • '>' = Greater

Callbacks

BrickletHumidityV2.CALLBACK_HUMIDITY
Function ID:
  • 4
Response:
  • humidity – Type: uint16, Unit: 1/100 %, Range: [0 to 10000]

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

The response value is the same as get_humidity.

BrickletHumidityV2.CALLBACK_TEMPERATURE
Function ID:
  • 8
Response:
  • temperature – Type: int16, Unit: 1/100 °C, Range: [-4000 to 16500]

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

The response value is the same as get_temperature.

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.

BrickletHumidityV2.set_bootloader_mode
Function ID:
  • 235
Request:
  • mode – Type: uint8, Range: See meanings
Response:
  • status – Type: uint8, Range: See meanings

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 meanings are defined for the elements of this function:

For mode:

  • 0 = Bootloader
  • 1 = Firmware
  • 2 = Bootloader Wait For Reboot
  • 3 = Firmware Wait For Reboot
  • 4 = Firmware Wait For Erase And Reboot

For status:

  • 0 = OK
  • 1 = Invalid Mode
  • 2 = No Change
  • 3 = Entry Function Not Present
  • 4 = Device Identifier Incorrect
  • 5 = CRC Mismatch
BrickletHumidityV2.get_bootloader_mode
Function ID:
  • 236
Request:
  • empty payload
Response:
  • mode – Type: uint8, Range: See meanings

Returns the current bootloader mode, see set_bootloader_mode.

The following meanings are defined for the elements of this function:

For mode:

  • 0 = Bootloader
  • 1 = Firmware
  • 2 = Bootloader Wait For Reboot
  • 3 = Firmware Wait For Reboot
  • 4 = Firmware Wait For Erase And Reboot
BrickletHumidityV2.set_write_firmware_pointer
Function ID:
  • 237
Request:
  • pointer – Type: uint32, Unit: 1 B, Range: [0 to 232 - 1]
Response:
  • no response

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.

BrickletHumidityV2.write_firmware
Function ID:
  • 238
Request:
  • data – Type: uint8[64], Range: [0 to 255]
Response:
  • status – Type: uint8, 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.

BrickletHumidityV2.write_uid
Function ID:
  • 248
Request:
  • uid – Type: uint32, Range: [0 to 232 - 1]
Response:
  • no response

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.

BrickletHumidityV2.read_uid
Function ID:
  • 249
Request:
  • empty payload
Response:
  • uid – Type: uint32, Range: [0 to 232 - 1]

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