Modbus - Ambient Light Bricklet 3.0

This is the description of the Modbus protocol for the Ambient Light Bricklet 3.0. General information and technical specifications for the Ambient Light Bricklet 3.0 are summarized in its hardware description.

API

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

Basic Functions

BrickletAmbientLightV3.get_illuminance
Function ID:

1

Request:

empty payload

Response:
  • illuminance -- uint32

Returns the illuminance of the ambient light sensor. The measurement range goes up to about 100000lux, but above 64000lux the precision starts to drop. The illuminance is given in lux/100, i.e. a value of 450000 means that an illuminance of 4500lux is measured.

An illuminance of 0lux indicates that the sensor is saturated and the configuration should be modified, see set_configuration.

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

BrickletAmbientLightV3.set_configuration
Function ID:

5

Request:
  • illuminance_range -- uint8
  • integration_time -- uint8
Response:

no response

Sets the configuration. It is possible to configure an illuminance range between 0-600lux and 0-64000lux and an integration time between 50ms and 400ms.

The unlimited illuminance range allows to measure up to about 100000lux, but above 64000lux the precision starts to drop.

A smaller illuminance range increases the resolution of the data. A longer integration time will result in less noise on the data.

If the actual measure illuminance is out-of-range then the current illuminance range maximum +0.01lux is reported by get_illuminance and the CALLBACK_ILLUMINANCE callback. For example, 800001 for the 0-8000lux range.

With a long integration time the sensor might be saturated before the measured value reaches the maximum of the selected illuminance range. In this case 0lux is reported by get_illuminance and the CALLBACK_ILLUMINANCE callback.

If the measurement is out-of-range or the sensor is saturated then you should configure the next higher illuminance range. If the highest range is already in use, then start to reduce the integration time.

The default values are 0-8000lux illuminance range and 150ms integration time.

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

  • 6: unlimited, for illuminance_range
  • 0: 64000lux, for illuminance_range
  • 1: 32000lux, for illuminance_range
  • 2: 16000lux, for illuminance_range
  • 3: 8000lux, for illuminance_range
  • 4: 1300lux, for illuminance_range
  • 5: 600lux, for illuminance_range
  • 0: 50ms, for integration_time
  • 1: 100ms, for integration_time
  • 2: 150ms, for integration_time
  • 3: 200ms, for integration_time
  • 4: 250ms, for integration_time
  • 5: 300ms, for integration_time
  • 6: 350ms, for integration_time
  • 7: 400ms, for integration_time
BrickletAmbientLightV3.get_configuration
Function ID:

6

Request:

empty payload

Response:
  • illuminance_range -- uint8
  • integration_time -- uint8

Returns the configuration as set by set_configuration.

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

  • 6: unlimited, for illuminance_range
  • 0: 64000lux, for illuminance_range
  • 1: 32000lux, for illuminance_range
  • 2: 16000lux, for illuminance_range
  • 3: 8000lux, for illuminance_range
  • 4: 1300lux, for illuminance_range
  • 5: 600lux, for illuminance_range
  • 0: 50ms, for integration_time
  • 1: 100ms, for integration_time
  • 2: 150ms, for integration_time
  • 3: 200ms, for integration_time
  • 4: 250ms, for integration_time
  • 5: 300ms, for integration_time
  • 6: 350ms, for integration_time
  • 7: 400ms, for integration_time

Advanced Functions

BrickletAmbientLightV3.get_spitfp_error_count
Function ID:

234

Request:

empty payload

Response:
  • error_count_ack_checksum -- uint32
  • error_count_message_checksum -- uint32
  • error_count_frame -- uint32
  • error_count_overflow -- uint32

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.

BrickletAmbientLightV3.set_bootloader_mode
Function ID:

235

Request:
  • mode -- uint8
Response:
  • status -- uint8

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 parameters of this function:

  • 0: bootloader, for mode
  • 1: firmware, for mode
  • 2: bootloader wait for reboot, for mode
  • 3: firmware wait for reboot, for mode
  • 4: firmware wait for erase and reboot, for mode
  • 0: ok, for status
  • 1: invalid mode, for status
  • 2: no change, for status
  • 3: entry function not present, for status
  • 4: device identifier incorrect, for status
  • 5: crc mismatch, for status
BrickletAmbientLightV3.get_bootloader_mode
Function ID:

236

Request:

empty payload

Response:
  • mode -- uint8

Returns the current bootloader mode, see set_bootloader_mode.

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

  • 0: bootloader, for mode
  • 1: firmware, for mode
  • 2: bootloader wait for reboot, for mode
  • 3: firmware wait for reboot, for mode
  • 4: firmware wait for erase and reboot, for mode
BrickletAmbientLightV3.set_write_firmware_pointer
Function ID:

237

Request:
  • pointer -- uint32
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.

BrickletAmbientLightV3.write_firmware
Function ID:

238

Request:
  • data -- uint8[64]
Response:
  • status -- uint8

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.

BrickletAmbientLightV3.set_status_led_config
Function ID:

239

Request:
  • config -- uint8
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 parameters of this function:

  • 0: off, for config
  • 1: on, for config
  • 2: show heartbeat, for config
  • 3: show status, for config
BrickletAmbientLightV3.get_status_led_config
Function ID:

240

Request:

empty payload

Response:
  • config -- uint8

Returns the configuration as set by set_status_led_config

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

  • 0: off, for config
  • 1: on, for config
  • 2: show heartbeat, for config
  • 3: show status, for config
BrickletAmbientLightV3.get_chip_temperature
Function ID:

242

Request:

empty payload

Response:
  • temperature -- int16

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.

BrickletAmbientLightV3.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!

BrickletAmbientLightV3.write_uid
Function ID:

248

Request:
  • uid -- uint32
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.

BrickletAmbientLightV3.read_uid
Function ID:

249

Request:

empty payload

Response:
  • uid -- uint32

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

BrickletAmbientLightV3.get_identity
Function ID:

255

Request:

empty payload

Response:
  • uid -- char[8]
  • connected_uid -- char[8]
  • position -- char
  • hardware_version -- uint8[3]
  • firmware_version -- uint8[3]
  • device_identifier -- uint16

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

BrickletAmbientLightV3.set_illuminance_callback_configuration
Function ID:

2

Request:
  • period -- uint32
  • value_has_to_change -- bool
  • option -- char
  • min -- uint32
  • max -- uint32
Response:

no response

The period in ms is the period with which the CALLBACK_ILLUMINANCE 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_ILLUMINANCE 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 meanings are defined for the parameters of this function:

  • x: off, for option
  • o: outside, for option
  • i: inside, for option
  • <: smaller, for option
  • >: greater, for option
BrickletAmbientLightV3.get_illuminance_callback_configuration
Function ID:

3

Request:

empty payload

Response:
  • period -- uint32
  • value_has_to_change -- bool
  • option -- char
  • min -- uint32
  • max -- uint32

Returns the callback configuration as set by set_illuminance_callback_configuration.

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

  • x: off, for option
  • o: outside, for option
  • i: inside, for option
  • <: smaller, for option
  • >: greater, for option

Callbacks

BrickletAmbientLightV3.CALLBACK_ILLUMINANCE
Function ID:

4

Response:
  • illuminance -- uint32

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

The response value is the same as get_illuminance.