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floatplane merged 1 commit into from
Jul 27, 2026
Merged

Improve MQTT and WiFi resilience #84

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127 changes: 75 additions & 52 deletions src/main.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -217,7 +217,9 @@ struct Config {

// Define global variables for network
const PROGMEM uint32_t WIFI_RETRY_INTERVAL_MS = 300000;
const PROGMEM uint32_t WIFI_RECONNECT_INTERVAL_MS = 30000;
Moment wifi_timeout(Moment::now());
Moment wifi_reconnect_timeout(Moment::now());

enum HttpStatusCodes {
httpOk = 200,
Expand Down Expand Up @@ -246,7 +248,12 @@ String ha_config_topic;
// sketch settings
const PROGMEM uint32_t CHECK_REMOTE_TEMP_INTERVAL_MS = 300000; // 5 minutes
const PROGMEM uint32_t MQTT_RETRY_INTERVAL_MS = 1000; // 1 second
const PROGMEM int64_t HP_RETRY_INTERVAL_MS = 1000LL; // 1 second
const PROGMEM uint32_t MQTT_MAX_RETRIES =
8; // Double the interval between retries up to this many times, then keep
// retrying forever at that maximum interval.
// Default values give a final retry interval of 1000ms * 2^8, which is 256
// seconds, about 4 minutes.
const PROGMEM int64_t HP_RETRY_INTERVAL_MS = 1000LL; // 1 second
const PROGMEM uint32_t HP_MAX_RETRIES =
10; // Double the interval between retries up to this many times, then keep
// retrying forever at that maximum interval.
Expand All @@ -272,6 +279,7 @@ boolean remoteTempActive = false;
HeatPump hp; // NOLINT(readability-identifier-length)
Moment lastMqttStatePacketSend(Moment::never());
Moment lastMqttRetry(Moment::never());
unsigned int mqttConnectionRetries;
Moment lastHpSync(Moment::never());
unsigned int hpConnectionRetries;
unsigned int hpConnectionTotalRetries;
Expand Down Expand Up @@ -313,8 +321,10 @@ void logConfig() {
LOG(F("File is empty"));
continue;
}
if (doc.containsKey("ap_pwd")) {
doc["ap_pwd"] = F("********");
for (const auto *const key : {"ap_pwd", "ota_pwd", "mqtt_pwd", "login_password"}) {
if (doc.containsKey(key)) {
doc[key] = F("********");
}
}
String contents;
serializeJsonPretty(doc, contents);
Expand Down Expand Up @@ -538,6 +548,10 @@ void initCaptivePortal() {
}

void initMqtt() {
// The default PubSubClient buffer of 256 bytes is barely large enough for the state topic
// payload, and too small with a long root topic or friendly name — publishes then fail
// silently. Discovery messages are streamed with beginPublish() and don't need the buffer.
mqtt_client.setBufferSize(1024);
mqtt_client.setServer(config.mqtt.server.c_str(), config.mqtt.port);
mqtt_client.setCallback(mqttCallback);
mqttConnect();
Expand Down Expand Up @@ -930,6 +944,7 @@ void handleStatus() {
#endif

if (server.hasArg("mrconn")) {
mqttConnectionRetries = 0;
mqttConnect();
}

Expand Down Expand Up @@ -1829,49 +1844,41 @@ void sendHomeAssistantConfig() {
}

void mqttConnect() {
// Loop until we're reconnected
int attempts = 0;
const int maxAttempts = 5;
while (!mqtt_client.connected()) {
// Attempt to connect
mqtt_client.connect(config.network.hostname.c_str(), config.mqtt.username.c_str(),
config.mqtt.password.c_str(), config.mqtt.ha_availability_topic().c_str(),
1, true, mqtt_payload_unavailable);
// If state < 0 (MQTT_CONNECTED) => network problem we retry 5 times and
// then waiting for MQTT_RETRY_INTERVAL_MS and retry reapeatly
if (mqtt_client.state() < MQTT_CONNECTED) {
if (attempts == maxAttempts) {
lastMqttRetry = Moment::now();
return;
}
delay(10);
attempts++;
}
// If state > 0 (MQTT_CONNECTED) => config or server problem we stop retry
else if (mqtt_client.state() > MQTT_CONNECTED) {
return;
}
// We are connected
else {
mqttTopicHandlers = {{config.mqtt.ha_mode_set_topic(), onSetMode},
{config.mqtt.ha_temp_set_topic(), onSetTemp},
{config.mqtt.ha_fan_set_topic(), onSetFan},
{config.mqtt.ha_vane_set_topic(), onSetVane},
{config.mqtt.ha_wideVane_set_topic(), onSetWideVane},
{config.mqtt.ha_remote_temp_set_topic(), onSetRemoteTemp},
{config.mqtt.ha_system_set_topic(), onSetSystem},
{config.mqtt.ha_debug_pckts_set_topic(), onSetDebugPackets},
{config.mqtt.ha_debug_logs_set_topic(), onSetDebugLogs},
{config.mqtt.ha_custom_packet(), onSetCustomPacket}};
for (const auto &[topic, _] : mqttTopicHandlers) {
mqtt_client.subscribe(topic.c_str());
}
mqtt_client.publish(config.mqtt.ha_availability_topic().c_str(), mqtt_payload_available,
true); // publish status as available
if (config.other.haAutodiscovery) {
sendHomeAssistantConfig();
}
}
// A single connection attempt per call: connect() blocks for several seconds when the broker
// is unreachable, so retrying in a loop here would starve the heat pump sync and the web
// server. The caller retries with exponential backoff instead.
mqtt_client.connect(config.network.hostname.c_str(), config.mqtt.username.c_str(),
config.mqtt.password.c_str(), config.mqtt.ha_availability_topic().c_str(), 1,
true, mqtt_payload_unavailable);
lastMqttRetry = Moment::now();
// If state < 0 (MQTT_CONNECTED) => network problem, back off before the next attempt
if (mqtt_client.state() < MQTT_CONNECTED) {
mqttConnectionRetries = min(mqttConnectionRetries + 1U, MQTT_MAX_RETRIES);
return;
}
// If state > 0 (MQTT_CONNECTED) => config or server problem we stop retry
if (mqtt_client.state() > MQTT_CONNECTED) {
return;
}
// We are connected
mqttConnectionRetries = 0;
mqttTopicHandlers = {{config.mqtt.ha_mode_set_topic(), onSetMode},
{config.mqtt.ha_temp_set_topic(), onSetTemp},
{config.mqtt.ha_fan_set_topic(), onSetFan},
{config.mqtt.ha_vane_set_topic(), onSetVane},
{config.mqtt.ha_wideVane_set_topic(), onSetWideVane},
{config.mqtt.ha_remote_temp_set_topic(), onSetRemoteTemp},
{config.mqtt.ha_system_set_topic(), onSetSystem},
{config.mqtt.ha_debug_pckts_set_topic(), onSetDebugPackets},
{config.mqtt.ha_debug_logs_set_topic(), onSetDebugLogs},
{config.mqtt.ha_custom_packet(), onSetCustomPacket}};
for (const auto &[topic, _] : mqttTopicHandlers) {
mqtt_client.subscribe(topic.c_str());
}
mqtt_client.publish(config.mqtt.ha_availability_topic().c_str(), mqtt_payload_available,
true); // publish status as available
if (config.other.haAutodiscovery) {
sendHomeAssistantConfig();
}
}

Expand All @@ -1886,6 +1893,14 @@ bool connectWifi() {
WiFi.mode(WIFI_STA);
delay(10);
}
WiFi.setAutoReconnect(true);
// Disable modem power saving: it trades a few tens of mW for latency spikes and dropped
// packets with some access points, and this device is always mains-powered.
#ifdef ESP32
WiFi.setSleep(false);
#else
WiFi.setSleepMode(WIFI_NONE_SLEEP);
#endif
#ifdef ESP32
WiFi.config(INADDR_NONE, INADDR_NONE, INADDR_NONE);
#endif
Expand Down Expand Up @@ -1978,15 +1993,21 @@ void loop() { // NOLINT(readability-function-cognitive-complexity)

server.handleClient();

// reset board to attempt to connect to wifi again if in ap mode or wifi
// dropped out and time limit passed
// If wifi dropped out, nudge the stack to reconnect every WIFI_RECONNECT_INTERVAL_MS;
// reset the board as a last resort if that hasn't succeeded within WIFI_RETRY_INTERVAL_MS.
// Also reset if we've been sitting in AP mode for that long with a valid config.
if (WiFi.getMode() == WIFI_STA and
WiFi.status() == WL_CONNECTED) { // NOLINT(bugprone-branch-clone)
wifi_timeout = Moment::now().offset(WIFI_RETRY_INTERVAL_MS);
wifi_reconnect_timeout = Moment::now().offset(WIFI_RECONNECT_INTERVAL_MS);
} else if (config.network.configured() and Moment::now() > wifi_timeout) {
LOG(F("Lost network connection, restarting..."));
// TODO(floatplane) do we really need to reboot here? Can we just try to reconnect?
LOG(F("Lost network connection and failed to reconnect, restarting..."));
restartAfterDelay(0);
} else if (config.network.configured() and WiFi.getMode() == WIFI_STA and
Moment::now() > wifi_reconnect_timeout) {
LOG(F("Lost network connection, trying to reconnect..."));
WiFi.reconnect();
wifi_reconnect_timeout = Moment::now().offset(WIFI_RECONNECT_INTERVAL_MS);
}

if (captive) {
Expand Down Expand Up @@ -2030,9 +2051,11 @@ void loop() { // NOLINT(readability-function-cognitive-complexity)
}

if (config.mqtt.configured()) {
// MQTT failed retry to connect
// MQTT failed, retry to connect with the same exponential backoff scheme as the
// heat pump connection
if (mqtt_client.state() < MQTT_CONNECTED) {
if (Moment::now() - lastMqttRetry > MQTT_RETRY_INTERVAL_MS) {
const int64_t durationNextRetry = (1LL << mqttConnectionRetries) * MQTT_RETRY_INTERVAL_MS;
if (Moment::now() - lastMqttRetry > durationNextRetry) {
mqttConnect();
}
}
Expand Down
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