HOWTO don't draw discrete graph when no data for that time

Hi,

First time playing with Grafana - I currently have a sensor sending data when it see a device. I am graphing the data with the Discrete graph however I would like the bar to ‘break’ when there is no data for that timestamp. Outcome - able to look back during the day and see when a device was present.

The request to the API to put the data in InfluxDB is

data,Device=41:7d:23:10:1c:24 Device-Address=“41:7d:23:10:1c:24”,Observer=“BLE-Logger-001”,Device-Name="",Device-TX-Power=0.00,Device-RSSI=-79.00

And my query in Grafana is

SELECT “Device-Address” FROM “data” WHERE time >= now() - 1h GROUP BY “Device”

Obviously that query does not provide what I would like however I can not identify a query that will.

I have control over the device sending the data to influx so if the format needs to change for Grafana that is possible.