AlexaCapability replaces the header-only AlexaInterface as what a device holds: 116 bytes with fixed places for
3 names, 4 action mappings and 2 state mappings, no std::vector or std::string. AlexaInterface and AlexaActions
stay as 1.x names; the five examples compile unchanged and announce the same bytes.
addCapability(row, instance) adds several capabilities of one generic controller. An instanced interface without
an instance or a name, an instance or semantics on an interface that takes none, and a full store are refused
with an ERROR line that says what to change.
PlaybackController and WakeOnLANController announce "properties": {} (AIF_EMPTY_PROPERTIES).
basicLight on a D1 mini: static RAM 30,788 -> 30,672 B, flash 330,509 -> 332,541 B; host tests 61 -> 77.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
AlexaInterfaces.h/.cpp hold one row per interface in program memory (28: namespace,
version, property names, flags, type), each row and string an object of its own, so
the linker keeps only the rows a sketch names. addCapability(AlexaInterfaceType) is
an always-inline switch that folds to one row; a type without a row is refused with
an error. The Event handler gets its type from the capabilities of the device.
Versions follow the interface pages (EndpointHealth 3.1, ThermostatController 3.2),
HumiditySensor is new, the two withdrawn interfaces and AlexaInterfaceUtils are gone.
Display category names are in flash. The discovery objects of the five examples are
unchanged: 14 new host tests compare them with what the previous commit announced.
basicLight on a D1 mini: static RAM 34,508 -> 30,788, flash 338,533 -> 330,509;
it links two rows, EndpointHealth and PowerController. Host tests: 47 -> 61.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
The library fetched every directive over HTTP (GET /Alex2ESP/<token>, the token taken from <root>/<id>/alexaDirective_e) and posted every report back over HTTP. The detour was built in 2024 because AsyncMqttClient hands a message larger than one TCP segment to onMessage in fragments. Alex2MQTT publishes the whole directive on <root>/<id>/alexaDirective, so the fragments are reassembled instead: by index/total, into one heap block of total + 1 bytes that is freed as soon as loop() has parsed it.
Removed: ESP8266HTTPClient with processHttpGet/processHttpPost and their two HTTPClient and two WiFiClient members; the 5-slot packet, topic and receive queues, combinedData, receivePayload and AlexaStatusMessage::outputString (17,264 bytes of .bss); the {MESSAGE_PAYLOAD_SPLIT} and {REPLACE_WITH_DATETIME} conventions; the subscription to the _e token topic; AlexaUtils.cpp (AlexaUtils::printMemoryInfo stays, in the header).
Receive: the bridge subscribes <root>/discover and <root>/+/alexaDirective. The MQTT callback only collects; loop() parses and dispatches, and answers discovery. A directive over ALEX2ESP_MAX_DIRECTIVE (2047) is refused. One directive is in flight: a second one that arrives before loop() ran is dropped. Both are logged. A byte-identical repeat of the waiting directive and a repeat of one of the last four messageIds (kept as 64-bit hashes, 32 bytes) are ignored, because the broker mirror delivers every message twice. The wildcard subscription also delivers the directives of other boards of the account; they are recognised by their topic before anything is allocated.
Publish: measureJson first. A message is refused when it is over ALEX2ESP_MAX_MESSAGE (2047), when its document overflowed, when there is no session, when the packet does not fit the largest free block, or when AsyncMqttClient returns 0. Every refusal is logged and returned as an AlexaSendResult; AlexaStatusMessage::send() keeps its bool. The limit now also applies to the discovery object of a device.
Time: timeOfSample is an ISO 8601 UTC instant from the clock of the board (gmtime_r + snprintf, no strftime). begin() calls configTime(0, 0, "pool.ntp.org", "time.nist.gov") and loop() holds the first connect until the clock is set or 5 s have passed. setTimeSource(false) leaves the clock to the sketch. AddContextProp() fills timeOfSample in when a hand-built property has none or carries the old placeholder.
Log: AlexaLog, with a level at run time (setLogLevel) and a ceiling at build time (ALEX2ESP_LOG_MAX), replaces the Serial prints and the Alex2ESP_DEBUG define; the new receive and publish paths need a line for every refusal. The log and the time stamp call vsnprintf/snprintf with a PROGMEM format and not the _P variants: newlib keeps those in one object with printf_P and sprintf_P, which links the FILE-based printf. Measured on basicLight: 5,776 bytes of flash.
For a sketch: the 1.x API is unchanged, the five examples compile unmodified and without warnings. loop() no longer blocks for two HTTP round trips per directive. send() publishes at once and returns false without a session, where 1.1.0 queued the report. The MQTT session opens from loop(), up to 5 s after begin(). getState() is CONNECTED once both subscriptions are acknowledged. The 1.2.0 section of readme.md lists every change; its transport section is rewritten.
Measured for d1_mini with empty credentials (PlatformIO 6.2.0, espressif8266 4.2.1, Arduino core 3.1.2), static RAM / flash in bytes, 1.1.0 -> this commit:
basicLight 52,768 / 350,885 -> 34,116 / 336,757
lightWithBrightness 52,880 / 354,729 -> 34,232 / 340,517
lightWithColorTemp 53,028 / 355,389 -> 34,380 / 341,177
tempSensor 52,676 / 349,441 -> 34,024 / 335,457
blindControl 52,900 / 353,069 -> 34,256 / 338,925
basicLight with -DALEX2ESP_LOG_MAX=0: 34,108 / 333,289. SNTP and the time stamp are 1,848 bytes of the flash figure.
Tests: platformio.ini with [env:native] and test/test_bridge_logic, 32 host tests of the logic in src/AlexaBridgeLogic.cpp (reassembly at every fragment size, both limits, repeats, publish checks, topics, time stamps). They also pass under -fsanitize=address,undefined. .gitignore no longer hides /test.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
