node-red-contrib-countdown-3000

node-red-contrib-countdown-3000 is a simple countdown node for Node-Red.

This code is based on node-red-contrib-countdown-2 by marc, see here for the general description:

https://github.com/marc-gist/node-red-contrib-countdown

This version is highly compatible with countdown-2 v1.4.2 with the following changes and fixes:

Changes / Enhancements

• STOP command fully evaluated - payload can be '0', 'off', 'stop', false or 0. -- Not case sensitive.

• START command fully evaluated - payload can be '1', 'on', 'start', true or 1. -- Not case sensitive.

  • Start will also cancel a paused count and begin again at the value set in the node's GUI interface. If you want to modify the count's start value, see the preload command below.

• Node output and node status messages are in seconds or minutes to match node config.

• Countdown goes to zero.

• Minor syntax changes and code tidies.

• If any action makes the countdown zero or negative, it will be stopped at zero.

• "control" input is now not case sensitive and can be a number or string with or without a sign:

  • If the input is a plain number, the current countdown is set to that number (in minutes or seconds according to node setting).
  • If the number is a negative integer (eg -10), a string with a plus or minus sign (eg: "+12" or "-12") OR the number is a string or decimal fraction (eg: 10.1 or "10.1" or -10.1 etc) the countdown is increased or decreased by that (truncated) amount (fraction part is discarded). Note that a positive integer input with a sign (eg: +10) is treated by javascript as plain old 10, so you can't use that method to add amounts to the count; use a fraction or make it a string (eg: 30.1 or "+30").
  • PAUSE will pause the countdown. The node will still output its current (paused) value every second. The countdown will resume with the next pause input (in effect, 'pause' toggles the counter), or if the countdown value is changed as above.
  • PRELOAD will restart a count at the current set value (provided it's not zero and the count is not currently running). This allows a count to be stopped, a new value set and the count started from this value rather than the one set in the node's interface.

Change Log

1.6.0:

• Fixed spurious 'true' output sent under some circumstances.
• Clarified comments about STOP and START commands.

1.5.0L and 1.5.1-L (minor text adjustment)

• Code forked from countdown-2 and bug fixes + enhancements applied.

Original notes from Countdown-2 V1.4.2

READ IN CONJUNCTION WITH CHANGES LISTED ABOVE

Fig. 1: Node appearance

Installation

In Node-RED (preferred)

• Via Manage Palette -> Search for "node-red-contrib-countdown-3000"

In a shell

• go to the Node-RED installation folder, e.g.: ~/.node-red
• run npm install node-red-contrib-countdown-3000

Usage

Node Configuration

Fig. 2: Node properties

Countdown (secs) property

Set the Countdown value to the desired countdown time in seconds. The timer will start with this countdown value to decrease the timer value (countdown start value). Minutes if the option "Counter is in Minutes" is checked.

Topic

The Topic can be set to any string value. This string is added to the output msg as an additional element msg.topic.

Note: No value is given to the topic.

Timer On payload, Timer Off payload

Set the Timer On payload to any payload type and value which is sent when the counter starts.
Set the Timer Off payload to any payload type and value which is sent when the counter elapses.
In both cases, also nothing to be emitted may be chosen.

Flags

You can configure the timer to

• Timer in Minutes (default is seconds)
• restart (reload) the timer to its countdown start value during the count down whenever a msg is received at the node's input.
• activate the ability to set the timer value to an arbitrary value during the count down with the use of a control msg.
• start the timer with a control msg (i.e. a msg with a control topic string).

Input

The node evaluates the following input msg types:

• Input msg with a msg.payload contents of false (boolean) or '0' (number).
  This msg type stops resp. finishes the timer. The Timer Off payload is emitted also in this case.
• Input msg with a msg.topic set to "control" and a msg.payload set to an arbitrary number value. This reloads the timer with the desired msg.payload value immediately and works at a running countdown as well as a non startet or elapsed countdown timer.
• All other input msg do start/restart the timer if it is stopped.
• See Node configuration for control topic options to cancel the timer.

Outputs

The node contains two outputs:

• The primary output (upper output) emits an output msg at the countdown start/stop instant of time. These msg.payload contents are configurable
• The secondary output (lower output) emits the remaining time every second during the timer runs. The msg.payload holds the remaining counting value

Examples (original)

Todo: create examples for modified control/stop/etc.

Basic behaviour

This example shows the basic behaviour with

• starting the timer via an input msg (inject node)
• showing the behaviour of the two outputs of the node

Just activate the inject and look at the output debug node status messages.

basic flow
Fig. 3: Basic example flow

Sending messages and retriggering

This example shows how to

• handle messages at the start and the end of the countdown
• retrigger the timer during it runs

Text messages are output on the first output at start and end of the countdown.
You can restart the timer by activating the inject node during the countdown runs.

messages and retriggering flow
Fig. 4: Message sending and retriggering example flow

Stopping the countdown timer

This example shows the two options to stop the countdown timer.

stopping timer flow
Fig. 5: Timer stopping example flow

Reloading the countdown timer

This example shows the functionality of reloading the countdown value during a running timer.

reloading timer flow
Fig. 6: Timer reload example flow