Hi, on a server I have a service estimating the delay for each bus-stop on my favorite line.
I will report that on a map. Each stop having a bus coming soon would display the information. Meaning objects to display will be created and destroyed after a while.
I though it’d be convenient to use map of HA, coupled with the MQTT broker already running, and using the autodiscovery topic.
In my service is currently able to create entities that appears in the right places, and destroy them.
Exemple of entity HA is discovering:
entity_id: device_tracker.bus_8012
state: not_home
last_changed: '2026-10-03T13:00:53.319Z'
last_updated: '2026-10-03T13:00:53.319Z'
attributes:
tracking_type: position
in_zones: []
source_type: gps
latitude: xx.xxxxx
longitude: xx.xxxxx
gps_accuracy: 5
friendly_name: Bus 8012
The limitation I am facing is that I can just have 3 charcaraters in the icon appearing on the HA map at a stop location. This is absolutely not enough to report wait time visual estimation for the 2 direction of the bus line. Displaying information as a picture would be a solution.
My service is able to add attribute through the MQTT. HA have the attribute in the entity.
With one exception: when the attribute name is exactly “entity_picture”, on HA the attribute does not exists even if it correctly exists on MQTT:
Topic homeassistant/device_tracker/toto/config :
{
"name": "Bus 8012",
"unique_id": "geo_tracker_toto_v2",
"state_topic": "bus_localize/toto/state",
"json_attributes_topic": "bus_localize/toto/attributes"
}
Topic bus_localize/toto/attributes :
{
"latitude": ...,
"longitude": ...,
"gps_accuracy": 5,
"entity_picture": "http://192.168.68.68:8080/MonImage.png"
}
Any idea ?
If this is build-in in HA, and should I spent time to redo using NodeRed instead of MQTT, shall it work or there is in any case an issue with pictures for dynamically created entities ?
Thank you