Arduino and Manual timestamps

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1

Hi,

I’m learning how to write to influxDB from a Wemos Mini, This is a new and testing experience for me. I am writing polled data, batched and not batched, to influxDB fine. However, the data I need to collect is from an interrupt which has the knock-on effect that I need to manage timestamps myself.

Does anyone have any Arduino code that I can use to learn from, I learn from examples of code rather than reading manuals. I’ve done some googling and looke don hear but without any sucsess.

I’m just trying to understand how to manually provide a time stamp, I’m already doing this;

sensor.addField(“blink”, 1);

and then

client.writePoint(sensor);

Just struggling to work out how to manually set time stamp rather than letting the InfluxDB Client set one for me.

Hope this makes sense and someone will help.

TIA

2

Hi, what library are you using ? Is this for influxdb v1 or v2 ?

3

Hi,

Thanks for getting back to me.

I am using the Arduino Library 3.3.0, specifically this one;

GitHub - tobiasschuerg/InfluxDB-Client-for-Arduino: Simple library for sending measurements to an InfluxDB with a single network request. Supports ESP8266 and ESP32..

Specifcally I don’t understand how to apply this part;
If you want to manage timestamp on your own, there are several ways how to set timestamp explicitly.

  • setTime(WritePrecision writePrecision) - Sets timestamp to actual time in desired precision
  • setTime(unsigned long long timestamp) - Sets timestamp in an offset since epoch. Correct precision must be set InfluxDBClient::setWriteOptions.
  • setTime(String timestamp) - Sets timestamp in an offset since epoch. Correct precision must be set InfluxDBClient::setWriteOptions.

The getTime() method allows copying timestamp between points.

thanks,

J

4

Are you collecting data in real-time? If yes, wouldn’t you want to use the current time as the timestamp?

For precision, I would suggest going with millisecond accuracy.

1 Like
5

I’m not really no, it’s counting the flashes of my electricity metere - a job I am currently running on a Pi which seems a bit overkill.

Because the flashes are interrupt driven and I am told I cannot put too much in the interrupt i have to process the InfluxDB stuff outside the interrupt so I store them in an array and then write them to Influx. If I have the influxDB write in the interrupt it’ll crash the Wemos :slight_smile:

Hopefully that makes sense.

J

6

Got it. Is it possible to do something inbetween? At the point the interrupt fires prepare the line protocol record and also grab the timestamp of “now” , and then push it onto the array ?

Edit: if you’re open to it, would you mind you sharing that part of the code in a </> code block ?