Counter Pin

Counter pins allow you to count pulses in various ways. You can simply count the number of pulses in a given period, apply a function to the pulses, or output the raw intervals. There is the option to scale the results up if you are using a clock divider on the input. You can also specify the time unit to use when returning intervals.

Note

Counter pins do not publish their initial states or when the polling interval timer fires. They publish only when the interval timer fires due to the precise timing nature of pulse counting.

Paths

The report of a counter pin is available on the path gpio/{pin-id}.

Path	Description
gpio/{pin-id}	Counter event report will be published here, see the Functions section for more details.

Configuration

The following additional options are added to the configuration. Optional settings are commented out with default values shown.

gpio:

  #debounce: 50

  pin-id:
    #pin mode: 'counter'
    #resistor: 'off'

    counter:
      #interval: 60
      #interrupt: 'rising'
      #function: 'count'
      #unit: 'ms'
      #divider: 1

  batch-id:
    #pin mode: 'counter'
    #resistor: 'off'

    counter:
      #interval: 60
      #interrupt: 'rising'
      #function: 'count'
      #unit: 'ms'
      #divider: 1

Module Settings

Option	Description
debounce	Pin change interrupt debounce time in milliseconds. Optional, default 50.

Single and Multiple Pin Definitions

Pin configuration section names must be unique as they are used as property IDs. Property IDs can only contain lowercase letters a-z, numbers 0-9, and hyphens -. The following settings apply to both single and multiple pin definitions:

Option	Description
pin mode	Pin mode, must be counter.
resistor	Pin pull resistor, can be pullup, pulldown (if supported), or off. Optional, default off.
interval	Pin report interval in whole seconds. Events will be cached during this period and a report will be published at the end. Optional, default 60.
interrupt	Pin change interrupt, can be rising, falling, or both. Optional, default rising.
function	Counter report function, see below for details. Available options are raw, count, average, median, min, max, frequency, frequency min, and frequency max. Optional, default count.
unit	Time unit to report in for functions that return intervals. Available options are s, ms, and ns. Optional, default ms.
divider	Clock divider factor used on the input. The report will be multiplied by this amount before publishing. Optional, default 1.

Functions

raw

The raw function will publish a JSON payload containing an array of all of the intervals in unit s between events during the last interval. This function ignores the divider option.

The first interval will be the time between the last event before this interval and the first event in the current interval. The first recorded event after the pin is setup may have strange values due to lack of a previous event to measure from.

{
    "pulses": []
}

count

The count function is the simplest and will publish an integer representing the number of pulses recorded during the last interval. The count will be multiplied by the divider factor.

average

The average function will calculate the average time in integer unit s of all events during the last interval. The result will be multiplied by divider and then published.

median

The median function will calculate the mathmatical median of all times in integer unit s of all events during the last interval. The result will be multiplied by divider and then published.

min and max

The min and max functions will select the lowest or highest time and convert it to integer unit s. The result will be multiplied by divider and published.

frequency

The average will be taken of all events in the last interval and the frequency will be calculated from this in hertz. The result will be multiplied by divider, rounded to 3 decimal places and published.

frequency min and frequency max

These functions work like frequency but will select the lowest or highest time between events for the calculation.