This program demonstrates how to configure counters, with debounce, using DIO channels.

LJ - 09.90 - counter_with_debouncing.lua

--[[
LJ - 09.90 - counter_with_debouncing.lua

This program demonstrates how to configure counters, with debounce, using DIO
channels. The debounce time for each counter will be between debounceInt and
2*debounceInt milliseconds. The debounce time is determined by the duration
of the interval and when in the interval the first input is received.
Original script:
https://labjack.com/support/software/examples/lua-scripting/counter-examples/23-counters-debounce

Components
----------

- LabJack T4
- Momentary button
  - Pin 1 to GND
  - Pin 2 to FIO4
- Wires
- Breadboard

Course
------
Data acquisition and automation with LabJack
https://app.techexplorations.com/courses/labjack/

--]]

print("Create and read a counter with debounce.")

local debounceInt  = 50     --50 ms debounce interval
local mbRead       = MB.R   --Local functions for faster processing
local mbWrite      = MB.W

--1 = Rising edge, 0 = falling
local edge = 1

local bits = 0
local bits_new = 99
local count = 0
local debouncedCount = 0
--0 will mean that the counter has not recently been incremented
local recentIncr = 0

--The throttle setting can correspond roughly with the length of the Lua
--script. A rule of thumb for deciding a throttle setting is
--throttle = (3*NumLinesCode) + 20
local throttleSetting = 100    --Default throttle setting is 10 instructions

LJ.setLuaThrottle(throttleSetting)
ThrottleSetting = LJ.getLuaThrottle()
print ("Current Lua Throttle Setting: ", throttleSetting)

LJ.IntervalConfig(0, debounceInt)          --set interval to debounceInt (ms)
local checkInterval=LJ.CheckInterval

while true do

  bits_new = mbRead(2004, 0) -- Read FIO4

  if bits ~= bits_new then
    if edge == 1 then
      if bits == 0 then
         count = count + 1
      end
    else
      if bits == 1 then
         count = count + 1
       end
    end
    bits = bits_new
  end

  --update debounced counter
  if checkInterval(0) then   --interval completed
      if recentIncr == 0 then
        if count > debouncedCount then
          recentIncr = 1
          debouncedCount = debouncedCount + 1
          count = debouncedCount
          if edge == 1 then
            print ("Rising total: ", debouncedCount)
          else
            print ("Falling total: ", debouncedCount)
          end
          mbWrite(46000, 3, debouncedCount) --Save in User RAM
        end
      else
        count      = debouncedCount
        recentIncr = 0
      end
  end
end