influxDB record an action

[877]

Hello all,

I would like to learn how to show sensor events in Grafana, where initial the value is either text (in this case "vibration", or true/false). I was thinking a bar chart with time across the bottom.

In this example. three window vibration sensors are feeding into influxDB:

Example object from MQTT node upon "vibration detected":

Note the "action" payload is only sent every so often when it detects vibration.

Contents of one of the function nodes:

When I go to Grafana, it shows "no data":

[ghayne]

Try enclosing all your Key fields in quotes!
"action": msg.payload.action...........................

Are you not getting an error from InfluxDB when you insert?

[Colin]

Add a debug node showing what you are actually sending to the db.

[Colin]

@ghayne

Try enclosing all your Key fields in quotes!
"action": msg.payload.action.

That isn't necessary when passing field and tag values to the influx out node, giving it an array with two entries.

[Colin]

However, you can't plot a graph of the action field, as it is a string. You can only graph numbers.

[877]

@Colin

Add a debug node showing what you are actually sending to the db.

This is what I am trying now, to convert the "vibration" to either 1 or 0.
Is this a good way of doing it?

//Convert the vibration payload to 1 or 0 value

if (msg.payload.action == "vibration") {
//shock detected
msg.payload.action = 1;
} 
else {
//nothing detected
msg.payload.action = 0;
}


//Now configure the payload as normal for influxD

msg.payload = [
    {
        action: msg.payload.action,
        strength:  msg.payload.strength,
        batteryPercent: msg.payload.battery,
        linkQuality: msg.payload.linkquality,
        batteryVolts: msg.payload.voltage
    },
    {
        topic: "Xiaomi_1_kitchen",
        make: "aqara",
        location: "kitchen",
        connection: "zigbee",
        power: "battery",
        friendlyname: "Kitchen window"
    }
];

which then sends this:

[Colin]

@877

Is this a good way of doing it?

That is ok, you shouuld use === here though, did not the editor suggest that? Also you can make it a bit more concise using
msg.payload = msg.payload.action === "vibration" ? 1 : 0

Note that you will have to drop the existing measurement in influx in order to change the field type from string to number

[877]

@Colin

That is ok, you shouuld use === here though, did not the editor suggest that? Also you can make it a bit more concise using
msg.payload = msg.payload.action === "vibration" ? 1 : 0

Note that you will have to drop the existing measurement in influx in order to change the field type from string to number

That's great thanks, I have seen that before now I see it in front of me

I need to look again how to drop values with certain tags, not sure I could do it before....

[Colin]

You can't drop part of a measurement. You have to drop the whole measurement (in order to change a field type). At least I believe that is the case.

[877]

Ah that's what I remember too. For now I just changed the key value to "vibration" and will ignore the "action" one.

Next, I need to fix it in Grafana so it shows more of a square wave (if that makes sense), rather than filling in the gaps between 1's and 0's like this:

[Colin]

@877

I need to fix it in Grafana so it shows more of a square wave

There is a Staircase option available for the whole graph, or you can use the Overrides feature to apply it to just one line.

[877]

Thanks for the help, much appreciated!

[877]

In case anyone searches in the future, it was fixed by using staircase option as suggested by Colin, and setting fill to "none", where it was previously "linear" - doh!