Shortest repeat interval time?

General
1

Hi there,

When i put the inject object, it allows us to Inject once after "x" seconds, then
Repeat Interval "N" seconds.

On the x seconds (Inject once after...), how small time can i go?
On the N seconds (repeat interval), can i go in milliseconds range?

2

You can enter 0.1 or 0.0001 if you want - but the question is, why?

This is primarily an events based programming environment & very efficient at what it does. Constantly polling is not the best design pattern

Perhaps if you explain what you are trying to achieve we can better advise.

3

I have a arduino hardware that receive an input signal. The signal might come and goes maybe within 10ms every hour.

Would like node-red to be able to detect this input and send it to a database with a timestamp when this input goes high.

4

How is the arduino interfaced with node-red?

Serial connection? MQTT? Other?

5

Its communicating serially.

6

ok, so then when the serial data arrives, you can simply test the value then trigger a database write if the value is seen - unless - you have to send a serial message to request the value?

Questions:

  • Do you have the src code for the aurduino?
  • Does your aurduino have WiFi (and would you switch to WiFi or wired Ethernet?
7

No source code in the arduino yet.
Will be using wired ethernet.

8

Then you can simply write to the serial port when an input change is detected in your Arduino source code. Then it will be 100% event driven (send the change of value when your Arduino detects a change) - no need to poll

In which case - could you not use MQTT instead of serial? Then it will be 100% event driven (publish the change of value when your Arduino detects a change) - no need to poll

9

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