Method findConnectedPinsImpl

examples/AutoResearch/AutoResearchRemote.cpp:1141–1289

}

fl::json AutoResearchRemoteControl::findConnectedPinsImpl(const fl::json& args) {
    fl::json response = fl::json::object();

    // Parse optional arguments: [{startPin: int, endPin: int, autoApply: bool}]
    int start_pin = 0;
    int end_pin = 8;  // Default range: GPIO 0-8 (safe range, avoids USB/flash/strapping pins)
    bool auto_apply = true;  // If true, automatically apply found pins

    if (args.is_array() && args.size() >= 1 && args[0].is_object()) {
        fl::json config = args[0];
        if (config.contains("startPin") && config["startPin"].is_int()) {
            start_pin = static_cast<int>(config["startPin"].as_int().value());
        }
        if (config.contains("endPin") && config["endPin"].is_int()) {
            end_pin = static_cast<int>(config["endPin"].as_int().value());
        }
        if (config.contains("autoApply") && config["autoApply"].is_bool()) {
            auto_apply = config["autoApply"].as_bool().value();
        }
    }

    // Validate range
    if (start_pin < 0 || start_pin > 48 || end_pin < 0 || end_pin > 48 || start_pin >= end_pin) {
        response.set("error", "InvalidRange");
        response.set("message", "Pin range must be 0-48 with startPin < endPin");
        return response;
    }

    FL_DBG("[PIN PROBE] Searching for connected pin pairs in range " << start_pin << "-" << end_pin);

    // Helper lambda to test if two pins are connected
    auto testPinPair = [](int tx, int rx) -> bool {
        // Test 1: TX drives LOW, RX has pullup → RX should read LOW if connected
        pinMode(tx, OUTPUT);
        pinMode(rx, INPUT_PULLUP);
        digitalWrite(tx, LOW);
        delay(2);  // Allow signal to settle
        int rx_when_tx_low = digitalRead(rx);

        // Test 2: TX drives HIGH → RX should read HIGH if connected
        digitalWrite(tx, HIGH);
        delay(2);  // Allow signal to settle
        int rx_when_tx_high = digitalRead(rx);

        // Restore pins to safe state
        pinMode(tx, INPUT);
        pinMode(rx, INPUT);

        return (rx_when_tx_low == LOW) && (rx_when_tx_high == HIGH);
    };

    // Search for connected adjacent pin pairs (n, n+1)
    int found_tx = -1;
    int found_rx = -1;
    fl::json tested_pairs = fl::json::array();

    for (int pin = start_pin; pin < end_pin; pin++) {
        int tx_candidate = pin;