scanning for available networks before going to AP mode

scan for wifi networks before going to config mode to avoid wifi mode changes
select channel with lowest signal for AP mode

airrohr-firmware/Versions.md

@@ -1,3 +1,7 @@
+NRZ-2018-110-B4
+* scan for wifi networks before going to config mode to avoid wifi mode changes
+* select channel with lowest signal for AP mode
+
 NRZ-2018-110-B3
 * cosmetic changes to get rid of some compiler warnings
 

airrohr-firmware/airrohr-firmware.ino

@@ -96,7 +96,7 @@
  *
  ************************************************************************/
 // increment on change
-#define SOFTWARE_VERSION "NRZ-2018-110-B3"
+#define SOFTWARE_VERSION "NRZ-2018-110-B4"
 
 /*****************************************************************
  * Includes *
@@ -418,6 +418,18 @@ unsigned long count_sends = 0;
 unsigned long next_display_millis = 0;
 unsigned long next_display_count = 0;
 
+struct struct_wifiInfo {
+ char ssid[35];
+ uint8_t encryptionType;
+ int32_t RSSI;
+ int32_t channel;
+ bool isHidden;
+};
+uint8_t size_wifiInfo = 35 + sizeof(uint8_t) + sizeof(int32_t) + sizeof(uint8_t) + sizeof(bool);
+
+struct struct_wifiInfo *wifiInfo;
+uint8_t count_wifiInfo;
+
 #define data_first_part "{\"software_version\": \"{v}\", \"sensordatavalues\":["
 
 /*****************************************************************
@@ -1349,7 +1361,7 @@ void webserver_config() {
  page_content += F("</table><br/>");
  page_content += F("<br/></form>");
  if (WiFi.status() != WL_CONNECTED) { // scan for wlan ssids
- page_content += F("<script>window.setTimeout(load_wifi_list,3000);</script>");
+ page_content += F("<script>window.setTimeout(load_wifi_list,1000);</script>");
  }
  } else {
 
@@ -1478,53 +1490,50 @@ void webserver_config() {
  * Webserver wifi: show available wifi networks *
  *****************************************************************/
 void webserver_wifi() {
- WiFi.disconnect();
- debug_out(F("scan for wifi networks..."), DEBUG_MIN_INFO, 1);
- int n = WiFi.scanNetworks();
  debug_out(F("wifi networks found: "), DEBUG_MIN_INFO, 0);
- debug_out(String(n), DEBUG_MIN_INFO, 1);
+ debug_out(String(count_wifiInfo), DEBUG_MIN_INFO, 1);
  String page_content = "";
- if (n == 0) {
+ if (count_wifiInfo == 0) {
  page_content += F("<br/>");
  page_content += FPSTR(INTL_KEINE_NETZWERKE);
  page_content += F("<br/>");
  } else {
  page_content += FPSTR(INTL_NETZWERKE_GEFUNDEN);
- page_content += String(n);
+ page_content += String(count_wifiInfo);
  page_content += F("<br/>");
- int indices[n];
+ int indices[count_wifiInfo];
  debug_out(F("output config page 2"), DEBUG_MIN_INFO, 1);
- for (int i = 0; i < n; i++) {
+ for (int i = 0; i < count_wifiInfo; i++) {
  indices[i] = i;
  }
- for (int i = 0; i < n; i++) {
- for (int j = i + 1; j < n; j++) {
- if (WiFi.RSSI(indices[j]) > WiFi.RSSI(indices[i])) {
+ for (int i = 0; i < count_wifiInfo; i++) {
+ for (int j = i + 1; j < count_wifiInfo; j++) {
+ if (wifiInfo[indices[j]].RSSI > wifiInfo[indices[i]].RSSI) {
  std::swap(indices[i], indices[j]);
  }
  }
  }
  String cssid;
  debug_out(F("output config page 3"), DEBUG_MIN_INFO, 1);
- for (int i = 0; i < n; i++) {
+ for (int i = 0; i < count_wifiInfo; i++) {
  if (indices[i] == -1) {
  continue;
  }
- cssid = WiFi.SSID(indices[i]);
- for (int j = i + 1; j < n; j++) {
- if (cssid == WiFi.SSID(indices[j])) {
+ cssid = wifiInfo[indices[i]].ssid;
+ for (int j = i + 1; j < count_wifiInfo; j++) {
+ if (cssid == wifiInfo[indices[j]].ssid) {
  indices[j] = -1; // set dup aps to index -1
  }
  }
  }
  page_content += F("<br/><table>");
  //if(n > 30) n=30;
- for (int i = 0; i < n; ++i) {
+ for (int i = 0; i < count_wifiInfo; ++i) {
  if (indices[i] == -1) {
  continue;
  }
  // Print SSID and RSSI for each network found
- page_content += wlan_ssid_to_table_row(WiFi.SSID(indices[i]), ((WiFi.encryptionType(indices[i]) == ENC_TYPE_NONE) ? " " : "*"), WiFi.RSSI(indices[i]));
+ page_content += wlan_ssid_to_table_row(wifiInfo[indices[i]].ssid, ((wifiInfo[indices[i]].encryptionType == ENC_TYPE_NONE) ? " " : "*"), wifiInfo[indices[i]].RSSI);
  }
  page_content += F("</table><br/><br/>");
  }
@@ -1865,6 +1874,10 @@ void setup_webserver() {
 void wifiConfig() {
  const byte DNS_PORT = 53;
  int retry_count = 0;
+ String SSID;
+ uint8_t* BSSID;
+ int channels_rssi[14];
+ uint8_t AP_channel = 1;
  DNSServer dnsServer;
  IPAddress apIP(192, 168, 4, 1);
  IPAddress netMsk(255, 255, 255, 0);
@@ -1878,9 +1891,30 @@ void wifiConfig() {
  wificonfig_loop = true;
 
  WiFi.disconnect(true);
+ debug_out(F("scan for wifi networks..."), DEBUG_MIN_INFO, 1);
+ count_wifiInfo = WiFi.scanNetworks(false, true);
+ wifiInfo = (struct_wifiInfo *) malloc(count_wifiInfo * 100);
+ for (int i = 0; i < 14; i++) {
+ channels_rssi[i] = -100;
+ }
+ for (int i = 0; i < count_wifiInfo; i++) {
+ WiFi.getNetworkInfo(i, SSID, wifiInfo[i].encryptionType, wifiInfo[i].RSSI, BSSID, wifiInfo[i].channel, wifiInfo[i].isHidden);
+ SSID.toCharArray(wifiInfo[i].ssid, 35);
+ if (wifiInfo[i].RSSI > channels_rssi[wifiInfo[i].channel]) {
+ channels_rssi[wifiInfo[i].channel] = wifiInfo[i].RSSI;
+ }
+ }
+ if ((channels_rssi[1] < channels_rssi[6]) && (channels_rssi[1] < channels_rssi[11])) {
+ AP_channel = 1;
+ } else if ((channels_rssi[6] < channels_rssi[1]) && (channels_rssi[6] < channels_rssi[11])) {
+ AP_channel = 6;
+ } else {
+ AP_channel = 11;
+ }
+
  WiFi.mode(WIFI_AP);
  WiFi.softAPConfig(apIP, apIP, netMsk);
- WiFi.softAP(fs_ssid, fs_pwd);
+ WiFi.softAP(fs_ssid, fs_pwd, AP_channel);
  debug_out(String(WLANPWD), DEBUG_MIN_INFO, 1);
 
  dnsServer.setErrorReplyCode(DNSReplyCode::NoError);
@@ -1907,6 +1941,8 @@ void wifiConfig() {
  WiFi.softAPdisconnect(true);
  WiFi.mode(WIFI_STA);
 
+ free(wifiInfo);
+
  dnsServer.stop();
 
  delay(100);