MQTT - Analog In Bricklet

This is the description of the MQTT API bindings for the Analog In Bricklet. General information and technical specifications for the Analog In Bricklet are summarized in its hardware description.

An installation guide for the MQTT API bindings is part of their general description.

Examples

The example code below is Public Domain (CC0 1.0).

Simple

Download (example-simple.txt)

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# Change XYZ to the UID of your Analog In Bricklet

setup:
    # Get current voltage
    subscribe to tinkerforge/response/analog_in_bricklet/XYZ/get_voltage
    publish '' to tinkerforge/request/analog_in_bricklet/XYZ/get_voltage

Callback

Download (example-callback.txt)

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# Change XYZ to the UID of your Analog In Bricklet

setup:
    # Handle incoming voltage callbacks
    subscribe to tinkerforge/callback/analog_in_bricklet/XYZ/voltage
    publish '{"register": true}' to tinkerforge/register/analog_in_bricklet/XYZ/voltage # Register voltage callback
    
    # Set period for voltage callback to 1s (1000ms)
    # Note: The voltage callback is only called every second
    #       if the voltage has changed since the last call!
    publish '{"period": 1000}' to tinkerforge/request/analog_in_bricklet/XYZ/set_voltage_callback_period

Threshold

Download (example-threshold.txt)

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# Change XYZ to the UID of your Analog In Bricklet

setup:
    # Get threshold callbacks with a debounce time of 10 seconds (10000ms)
    publish '{"debounce": 10000}' to tinkerforge/request/analog-in_bricklet/XYZ/set_debounce_period
    
    # Handle incoming voltage reached callbacks
    subscribe to tinkerforge/callback/analog_in_bricklet/XYZ/voltage_reached
    publish '{"register": true}' to tinkerforge/register/analog_in_bricklet/XYZ/voltage_reached # Register voltage_reached callback
    
    # Configure threshold for voltage "smaller than 5 V"
    publish '{"option": "smaller", "min": 5000, "max": 0}' to tinkerforge/request/analog_in_bricklet/XYZ/set_voltage_callback_threshold

API

All published payloads to and from the MQTT bindings are in JSON format.

If an error occures, the bindings publish a JSON object containing the error message as attribute "_ERROR". It is published on the corresponding response topic: .../response/... for .../request/... and .../callback/... for .../register/....

Basic Functions

request/analog_in_bricklet/<UID>/get_voltage
Response payload:
  • voltage -- int

Returns the voltage of the sensor. The value is in mV and between 0V and 45V. The resolution between 0 and 6V is about 2mV. Between 6 and 45V the resolution is about 10mV.

If you want to get the voltage periodically, it is recommended to use the register/analog_in_bricklet/<UID>/voltage callback and set the period with request/analog_in_bricklet/<UID>/set_voltage_callback_period.

request/analog_in_bricklet/<UID>/set_range
Request payload:
  • range -- int (has symbols)

Sets the measurement range. Possible ranges:

  • 0: Automatically switched
  • 1: 0V - 6.05V, ~1.48mV resolution
  • 2: 0V - 10.32V, ~2.52mV resolution
  • 3: 0V - 36.30V, ~8.86mV resolution
  • 4: 0V - 45.00V, ~11.25mV resolution
  • 5: 0V - 3.3V, ~0.81mV resolution, new in version 2.0.3 (Plugin)

The default measurement range is 0.

The following symbols are available for this function:

for range:

  • "Automatic" = 0
  • "UpTo6V" = 1
  • "UpTo10V" = 2
  • "UpTo36V" = 3
  • "UpTo45V" = 4
  • "UpTo3V" = 5

New in version 2.0.1 (Plugin).

request/analog_in_bricklet/<UID>/get_range
Response payload:
  • range -- int (has symbols)

Returns the measurement range as set by request/analog_in_bricklet/<UID>/set_range.

The following symbols are available for this function:

for range:

  • "Automatic" = 0
  • "UpTo6V" = 1
  • "UpTo10V" = 2
  • "UpTo36V" = 3
  • "UpTo45V" = 4
  • "UpTo3V" = 5

New in version 2.0.1 (Plugin).

Advanced Functions

request/analog_in_bricklet/<UID>/get_analog_value
Response payload:
  • value -- int

Returns the value as read by a 12-bit analog-to-digital converter. The value is between 0 and 4095.

Note

The value returned by request/analog_in_bricklet/<UID>/get_voltage is averaged over several samples to yield less noise, while request/analog_in_bricklet/<UID>/get_analog_value gives back raw unfiltered analog values. The only reason to use request/analog_in_bricklet/<UID>/get_analog_value is, if you need the full resolution of the analog-to-digital converter.

If you want the analog value periodically, it is recommended to use the register/analog_in_bricklet/<UID>/analog_value callback and set the period with request/analog_in_bricklet/<UID>/set_analog_value_callback_period.

request/analog_in_bricklet/<UID>/set_averaging
Request payload:
  • average -- int

Set the length of a averaging for the voltage value.

Setting the length to 0 will turn the averaging completely off. If the averaging is off, there is more noise on the data, but the data is without delay.

The default value is 50.

New in version 2.0.3 (Plugin).

request/analog_in_bricklet/<UID>/get_averaging
Response payload:
  • average -- int

Returns the averaging configuration as set by request/analog_in_bricklet/<UID>/set_averaging.

New in version 2.0.3 (Plugin).

request/analog_in_bricklet/<UID>/get_identity
Response payload:
  • uid -- string
  • connected_uid -- string
  • position -- char
  • hardware_version -- [int,int,int]
  • firmware_version -- [int,int,int]
  • device_identifier -- int (has symbols)
  • _display_name -- string

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. If symbolic output is not disabled, the device identifier is mapped to the corresponding name in the format used in topics.

The display name contains the Analog In's name in a human readable form.

Callback Configuration Functions

request/analog_in_bricklet/<UID>/set_voltage_callback_period
Request payload:
  • period -- int

Sets the period in ms with which the register/analog_in_bricklet/<UID>/voltage callback is triggered periodically. A value of 0 turns the callback off.

The register/analog_in_bricklet/<UID>/voltage callback is only triggered if the voltage has changed since the last triggering.

The default value is 0.

request/analog_in_bricklet/<UID>/get_voltage_callback_period
Response payload:
  • period -- int

Returns the period as set by request/analog_in_bricklet/<UID>/set_voltage_callback_period.

request/analog_in_bricklet/<UID>/set_analog_value_callback_period
Request payload:
  • period -- int

Sets the period in ms with which the register/analog_in_bricklet/<UID>/analog_value callback is triggered periodically. A value of 0 turns the callback off.

The register/analog_in_bricklet/<UID>/analog_value callback is only triggered if the analog value has changed since the last triggering.

The default value is 0.

request/analog_in_bricklet/<UID>/get_analog_value_callback_period
Response payload:
  • period -- int

Returns the period as set by request/analog_in_bricklet/<UID>/set_analog_value_callback_period.

request/analog_in_bricklet/<UID>/set_voltage_callback_threshold
Request payload:
  • option -- char (has symbols)
  • min -- int
  • max -- int

Sets the thresholds for the register/analog_in_bricklet/<UID>/voltage_reached callback.

The following options are possible:

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

The default value is ('x', 0, 0).

The following symbols are available for this function:

for option:

  • "Off" = 'x'
  • "Outside" = 'o'
  • "Inside" = 'i'
  • "Smaller" = '<'
  • "Greater" = '>'
request/analog_in_bricklet/<UID>/get_voltage_callback_threshold
Response payload:
  • option -- char (has symbols)
  • min -- int
  • max -- int

Returns the threshold as set by request/analog_in_bricklet/<UID>/set_voltage_callback_threshold.

The following symbols are available for this function:

for option:

  • "Off" = 'x'
  • "Outside" = 'o'
  • "Inside" = 'i'
  • "Smaller" = '<'
  • "Greater" = '>'
request/analog_in_bricklet/<UID>/set_analog_value_callback_threshold
Request payload:
  • option -- char (has symbols)
  • min -- int
  • max -- int

Sets the thresholds for the register/analog_in_bricklet/<UID>/analog_value_reached callback.

The following options are possible:

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

The default value is ('x', 0, 0).

The following symbols are available for this function:

for option:

  • "Off" = 'x'
  • "Outside" = 'o'
  • "Inside" = 'i'
  • "Smaller" = '<'
  • "Greater" = '>'
request/analog_in_bricklet/<UID>/get_analog_value_callback_threshold
Response payload:
  • option -- char (has symbols)
  • min -- int
  • max -- int

Returns the threshold as set by request/analog_in_bricklet/<UID>/set_analog_value_callback_threshold.

The following symbols are available for this function:

for option:

  • "Off" = 'x'
  • "Outside" = 'o'
  • "Inside" = 'i'
  • "Smaller" = '<'
  • "Greater" = '>'
request/analog_in_bricklet/<UID>/set_debounce_period
Request payload:
  • debounce -- int

Sets the period in ms with which the threshold callbacks

are triggered, if the thresholds

keep being reached.

The default value is 100.

request/analog_in_bricklet/<UID>/get_debounce_period
Response payload:
  • debounce -- int

Returns the debounce period as set by request/analog_in_bricklet/<UID>/set_debounce_period.

Callbacks

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with the corresponding .../register/... topic and an optional suffix. This suffix can be used to deregister the callback later.

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.

register/analog_in_bricklet/<UID>/voltage
Request payload:
  • register -- bool
Response payload:
  • voltage -- int

A callback can be registered for this event by publishing to the .../register/analog_in_bricklet/<UID>/voltage[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/analog_in_bricklet/<UID>/voltage[/<SUFFIX>] topic for each registered suffix.

This callback is triggered periodically with the period that is set by request/analog_in_bricklet/<UID>/set_voltage_callback_period. The callback payload is the voltage of the sensor.

The register/analog_in_bricklet/<UID>/voltage callback is only triggered if the voltage has changed since the last triggering.

register/analog_in_bricklet/<UID>/analog_value
Request payload:
  • register -- bool
Response payload:
  • value -- int

A callback can be registered for this event by publishing to the .../register/analog_in_bricklet/<UID>/analog_value[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/analog_in_bricklet/<UID>/analog_value[/<SUFFIX>] topic for each registered suffix.

This callback is triggered periodically with the period that is set by request/analog_in_bricklet/<UID>/set_analog_value_callback_period. The callback payload is the analog value of the sensor.

The register/analog_in_bricklet/<UID>/analog_value callback is only triggered if the voltage has changed since the last triggering.

register/analog_in_bricklet/<UID>/voltage_reached
Request payload:
  • register -- bool
Response payload:
  • voltage -- int

A callback can be registered for this event by publishing to the .../register/analog_in_bricklet/<UID>/voltage_reached[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/analog_in_bricklet/<UID>/voltage_reached[/<SUFFIX>] topic for each registered suffix.

This callback is triggered when the threshold as set by request/analog_in_bricklet/<UID>/set_voltage_callback_threshold is reached. The callback payload is the voltage of the sensor.

If the threshold keeps being reached, the callback is triggered periodically with the period as set by request/analog_in_bricklet/<UID>/set_debounce_period.

register/analog_in_bricklet/<UID>/analog_value_reached
Request payload:
  • register -- bool
Response payload:
  • value -- int

A callback can be registered for this event by publishing to the .../register/analog_in_bricklet/<UID>/analog_value_reached[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/analog_in_bricklet/<UID>/analog_value_reached[/<SUFFIX>] topic for each registered suffix.

This callback is triggered when the threshold as set by request/analog_in_bricklet/<UID>/set_analog_value_callback_threshold is reached. The callback payload is the analog value of the sensor.

If the threshold keeps being reached, the callback is triggered periodically with the period as set by request/analog_in_bricklet/<UID>/set_debounce_period.