ESP32 WiFiScan: no networks found

[yoursunny]

Board

Heltec WiFi Kit 32

Device Description

plain module on breadboard, powered by USB

Hardware Configuration

nothing connected

Version

v3.0.1

IDE Name

Arduino IDE 2.3.2

Operating System

Windows 10

Flash frequency

240 MHz

PSRAM enabled

no

Upload speed

021600

Description

ESP32 WiFiScan example returns "no networks found".
I expect it returns at least 2.4 GHz WiFi networks at my location.

Sketch

Examples - WiFi - WiFiScan (unchanged)

Debug Message

=========== Before Setup Start ===========
Chip Info:
------------------------------------------
  Model             : ESP32
  Package           : D0WD-Q6
  Revision          : 100
  Cores             : 2
  Frequency         : 240 MHz
  Embedded Flash    : No
  Embedded PSRAM    : No
  2.4GHz WiFi       : Yes
  Classic BT        : Yes
  BT Low Energy     : Yes
  IEEE 802.15.4     : No
------------------------------------------
INTERNAL Memory Info:
------------------------------------------
  Total Size        :   345956 B ( 337.8 KB)
  Free Bytes        :   315680 B ( 308.3 KB)
  Allocated Bytes   :    23212 B (  22.7 KB)
  Minimum Free Bytes:   310344 B ( 303.1 KB)
  Largest Free Block:   110580 B ( 108.0 KB)
------------------------------------------
Flash Info:
------------------------------------------
  Chip Size         :  4194304 B (4 MB)
  Block Size        :    65536 B (  64.0 KB)
  Sector Size       :     4096 B (   4.0 KB)
  Page Size         :      256 B (   0.2 KB)
  Bus Speed         : 80 MHz
  Bus Mode          : DIO
------------------------------------------
Partitions Info:
------------------------------------------
                nvs : addr: 0x00009000, size:    20.0 KB, type: DATA, subtype: NVS
            otadata : addr: 0x0000E000, size:     8.0 KB, type: DATA, subtype: OTA
               app0 : addr: 0x00010000, size:  1280.0 KB, type:  APP, subtype: OTA_0
               app1 : addr: 0x00150000, size:  1280.0 KB, type:  APP, subtype: OTA_1
             spiffs : addr: 0x00290000, size:  1408.0 KB, type: DATA, subtype: SPIFFS
           coredump : addr: 0x003F0000, size:    64.0 KB, type: DATA, subtype: COREDUMP
------------------------------------------
Software Info:
------------------------------------------
  Compile Date/Time : Jun 14 2024 21:40:34
  Compile Host OS   : windows
  ESP-IDF Version   : v5.1.4-51-g442a798083-dirty
  Arduino Version   : 3.0.1
------------------------------------------
Board Info:
------------------------------------------
  Arduino Board     : HELTEC_WIFI_KIT_32
  Arduino Variant   : heltec_wifi_kit_32
  Arduino FQBN      : esp32:esp32:heltec_wifi_kit_32:UploadSpeed=921600,CPUFreq=240,DebugLevel=debug,PSRAM=disabled,EraseFlash=none
============ Before Setup End ============
[   604][W][STA.cpp:533] disconnect(): STA already disconnected.
Setup done
=========== After Setup Start ============
INTERNAL Memory Info:
------------------------------------------
  Total Size        :   345956 B ( 337.8 KB)
  Free Bytes        :   268616 B ( 262.3 KB)
  Allocated Bytes   :    67716 B (  66.1 KB)
  Minimum Free Bytes:   267388 B ( 261.1 KB)
  Largest Free Block:   110580 B ( 108.0 KB)
------------------------------------------
GPIO Info:
------------------------------------------
  GPIO : BUS_TYPE[bus/unit][chan]
  --------------------------------------  
     1 : UART_TX[0]
     3 : UART_RX[0]
============ After Setup End =============
Scan start
Scan done
no networks found

Scan start
Scan done
no networks found

Other Steps to Reproduce

I tried v2.0.17 with same ESP32 board, and the WiFiScan example can find networks.
I tried v3.0.1 with an ESP32-C3 board, and the WiFiScan example can find networks.

I have checked existing issues, online documentation and the Troubleshooting Guide

• I confirm I have checked existing issues, online documentation and Troubleshooting guide.

[me-no-dev]

I suggest you upload 3.0.1 with erase of flash first, in case some old PHY data is left on the device

[yoursunny]

I performed esptool.exe erase_flash command and re-uploaded the sketch, but the issue persists.

[me-no-dev]

ok, last suggestion is to call WiFi.setMinSecurity(WIFI_AUTH_WEP); before starting the scan.

[yoursunny]

After reading recent issues, I realized that the Heltec V1 boards I have are using 26MHz crystal.
I have opened PR 9889 to update the board definitions.
With correct crystal frequency set, WiFiScan works on both boards.