From bd7ed17a9757058e892edc5945d56349ec68fc30 Mon Sep 17 00:00:00 2001
From: cjkas <slaw.cz@gmail.com>
Date: Sun, 11 Oct 2026 20:50:46 +0200
Subject: [PATCH] feat: log AP signal levels and roam for a 6 dB gain

The roaming scan found two APs for the SSID every 10 minutes but the log
never showed their signal, so there was no way to tell whether the
device at -70 dBm had a better AP to move to. Log each AP on the
roaming scans, show roams at info level, and switch for a 6 dB gain
instead of 10.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 src/ESPNetwork.cpp | 17 +++++++++++++----
 src/ESPNetwork.h   |  2 ++
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/src/ESPNetwork.cpp b/src/ESPNetwork.cpp
index 9a8cbd5..3abdc90 100644
--- a/src/ESPNetwork.cpp
+++ b/src/ESPNetwork.cpp
@@ -111,11 +111,11 @@ void ESPNetwork::loop() {
         if(this->getStrongestAP(settings.WIFI.ssid, bssid, &channel)) {
           if(!WiFi.BSSID() || memcmp(bssid, WiFi.BSSID(), sizeof(bssid)) != 0) {
             if(!this->connected()) {
-              ESP_LOGD(TAG, "Connecting to AP %02X:%02X:%02X:%02X:%02X:%02X CH: %d", bssid[0], bssid[1], bssid[2], bssid[3], bssid[4], bssid[5], channel);
+              ESP_LOGI(TAG, "Connecting to AP %02X:%02X:%02X:%02X:%02X:%02X CH: %d", bssid[0], bssid[1], bssid[2], bssid[3], bssid[4], bssid[5], channel);
               this->connectWiFi(bssid, channel);
             }
             else {
-              ESP_LOGD(TAG, "Found stronger AP %02X:%02X:%02X:%02X:%02X:%02X CH: %d", bssid[0], bssid[1], bssid[2], bssid[3], bssid[4], bssid[5], channel);
+              ESP_LOGI(TAG, "Found stronger AP %02X:%02X:%02X:%02X:%02X:%02X CH: %d", bssid[0], bssid[1], bssid[2], bssid[3], bssid[4], bssid[5], channel);
               this->changeAP(bssid, channel);
             }
           }
@@ -538,8 +538,9 @@ uint32_t ESPNetwork::getChipId() {
   return chipId;
 }
 bool ESPNetwork::getStrongestAP(const char *ssid, uint8_t *bssid, int32_t *channel) {
-  // The new AP must be at least 10dbm greater.
-  int32_t strength = this->connected() ? WiFi.RSSI() + 10 : -127;
+  // The new AP must be at least ROAM_MIN_GAIN_DB stronger.
+  const bool connected = this->connected();
+  int32_t strength = connected ? WiFi.RSSI() + ROAM_MIN_GAIN_DB : -127;
   int32_t chan = -1;
   memset(bssid, 0x00, 6);
   esp_task_wdt_delete(NULL);
@@ -548,6 +549,14 @@ bool ESPNetwork::getStrongestAP(const char *ssid, uint8_t *bssid, int32_t *chann
   esp_task_wdt_add(NULL);
   for(int16_t i = 0; i < n; i++) {
     if(WiFi.SSID(i).compareTo(ssid) == 0) {
+      // Only on the roaming scans, so the log shows whether a better AP is
+      // around without filling up while we scan to reconnect.
+      if(connected) {
+        const uint8_t *b = WiFi.BSSID(i);
+        const uint8_t *cur = WiFi.BSSID();
+        ESP_LOGI(TAG, "AP %02X:%02X:%02X:%02X:%02X:%02X ch %ld %ld dBm%s", b[0], b[1], b[2], b[3], b[4], b[5],
+          (long)WiFi.channel(i), (long)WiFi.RSSI(i), (cur && memcmp(b, cur, 6) == 0) ? " (connected)" : "");
+      }
       if(WiFi.RSSI(i) > strength) { 
         strength = WiFi.RSSI(i); 
         memcpy(bssid, WiFi.BSSID(i), 6); 
diff --git a/src/ESPNetwork.h b/src/ESPNetwork.h
index f1594d0..08cd562 100644
--- a/src/ESPNetwork.h
+++ b/src/ESPNetwork.h
@@ -12,6 +12,8 @@
 // changes and not more often than this.
 #define RSSI_EMIT_MIN_DBM 3
 #define RSSI_EMIT_MIN_MS 10000
+// A roaming scan only moves to another AP this much stronger.
+#define ROAM_MIN_GAIN_DB 6
 class ESPNetwork {
   protected:
     unsigned long lastEmit = 0;