JSON Output

When compiled with MYCILA_JSON_SUPPORT, the manager and every task can serialize themselves into an ArduinoJson object. This is intended for telemetry: send the whole task tree over MQTT, HTTP or Serial in one call.

Enabling

build_flags =
  -D MYCILA_JSON_SUPPORT

lib_deps =
  bblanchon/ArduinoJson

Exporting

#include <ArduinoJson.h>
#include <MycilaTaskManager.h>

void outputJson() {
  JsonDocument doc;
  tasks.toJson(doc.to<JsonObject>());
  serializeJson(doc, Serial);
  Serial.println();
}

Output Shape

{
  "name": "loop()",
  "state": "RUNNING",
  "stats": {
    "count": 15,
    "unit_divider": 1,
    "bins": [3, 12, 0, 0, 0, 0]
  },
  "tasks": [
    {
      "name": "sayHello",
      "type": "FOREVER",
      "paused": false,
      "enabled": true,
      "interval": 1000,
      "state": "IDLE",
      "stats": {
        "count": 15,
        "unit_divider": 1,
        "bins": [0, 15, 0, 0, 0, 0]
      }
    },
    {
      "name": "ping",
      "type": "ONCE",
      "paused": true,
      "enabled": true,
      "interval": 0,
      "state": "IDLE"
    }
  ]
}

Manager fields

Field	Type	Description
name	string	Manager name
state	string	"RUNNING", "PAUSING" or "PAUSED"
stats	object	Present only if profiling is enabled and data was recorded
tasks	array	Every registered task

Task fields

Field	Type	Description
name	string	Task name
type	string	"ONCE" or "FOREVER"
paused	boolean	Current pause state
enabled	boolean	Result of the enabled predicate
interval	number	Interval in milliseconds
state	string	"IDLE", "RUNNING" or "FINALIZING"
stats	object	Present only if profiling is enabled and data was recorded

Statistics fields

Field	Type	Description
count	number	Number of recorded executions
unit_divider	number	Unit divider used when recording
bins	array	Count per power-of-2 bin

Notes

• toJson() is const, so it is safe to call from a read-only telemetry task.
• The stats sub-object is emitted only when _stats exists and both bins() and count() are non-zero — an idle task produces a compact entry.
• The manager always emits a tasks array, even when it is empty.
• Neither lastEndTime() nor remainingTime() is exported: the JSON describes configuration and profiling, not the live scheduling position. Query them through the API if you need them.
• state is instantaneous and racy by nature: it reports what was true when toJson() read it, which is only meaningful while nobody else is driving the manager.
• The manager state and the task state are different enums with different values: RUNNING/PAUSING/PAUSED for the dispatch gate, IDLE/RUNNING/FINALIZING for a single execution.
• Both Task::toJson() and BinStatistics::toJson() are compiled away unless MYCILA_JSON_SUPPORT is defined, so there is zero cost when the feature is off.
• Combine with Profiling & Statistics — without profiling there is no stats key.

Minimal Telemetry Task

tasks.newTask("telemetry", [](void* params) {
  JsonDocument doc;
  tasks.toJson(doc.to<JsonObject>());
  serializeJson(doc, Serial);
  Serial.println();
  tasks.log();
}).setInterval(5000);