A controller is a component to enable a plugin to send data elsewhere.

  • Up-to 3 controllers can be active in ESPEasy.

  • Per plugin up-to 3 active controllers can be selected.

  • For some controllers an additional parameter can be given.

For example, Domoticz needs an ‘IDX’ value to identify the configured entry in Domoticz for which new data is sent.

Controller Parameters

Generic fields

  • Protocol - The type of controller (e.g. ThingSpeak/OpenHAB MQTT/etc.)

  • Locate Controller - Selection between hostname/IP

  • Controller Hostname/IP - The address to reach the selected service

  • Controller Port - TCP/UDP Port number (0…65536)

  • Enabled - Whether or not the controller is active.

Send queue parameters

Controllers have a queue to keep unsent messages. This queue is used to handle message bursts and also store messages which are recorded before WiFi connection is made or during lost connection.

  • Minimum Send Interval - Minimum time between two messages in msec.

  • Max Queue Depth - Maximum length of the buffer queue to keep unsent messages.

  • Max Retries - Maximum number of retries to send a message.

  • Full Queue Action - How to handle when queue is full, ignore new or delete oldest message.

  • Check Reply - When set to false, a sent message is considered always successful.

  • Client Timeout - Timeout in msec for an network connection used by the controller.

  • Sample Set Initiator - Some controllers (e.g. C018 LoRa/TTN) can mark samples to belong to a set of samples. A new sample from set task index will increment this counter. Especially useful for controllers which cannot send samples in a burst. This makes the receiving time stamp useless to detect what samples were taken around the same time. The sample set counter value can help matching received samples to a single set.


Be careful when setting the timeout too high. For almost all controllers, sending data is a blocking call, so it may halt execution of other code on the node. With timouts longer than 2 seconds, the ESP may reboot as the software watchdog may step in.

Sample ThingSpeak configuration

Some controllers, like ThingSpeak, need a specific configuration. ThingSpeak only allows a message every 15 seconds for the free accounts.

  • Minimum Send Interval - 15000 msec

  • Max Queue Depth - 1 (only report the last value)

  • Max Retries - 2

  • Full Queue Action - Delete Oldest

  • Check Reply - Check Acknowledgment (VERY IMPORTANT)

  • Client Timeout - 500 msec (server is online, so timeout must be a bit longer)

Controller user credentials

  • Controller User - User name (optional)

  • Controller Password - Password (optional)