ESP32 doesn't save a password to configured access point and configuration web page hangs on connecting

[pawelc06]

Description

Running default_demo example.
ESP32 doesn't save a password to configured access point and configuration web page hangs on connecting.
ESP 32 STA gets IP from DHCP.
After ESP32 reset it is visible in logs that configuration of access point was not saved.
I tried with at least 2 different access points with the same effect.

Steps to Reproduce

1. Erase the ESP32 device
2. Flash ESP32 with master branch(19.08.2020)
3. Reset device and enable setial monitor to observe the logs
4. Connect to esp32 wi fi access point
5. Open configuration web page
6. Select home router access point (in this case 'vault05')
7. Enter password and click Join
8. Connection to vault05 screen displays permanently with pulsing circle

System Configuration

Module used: ESP32 DEVKITV1
Visual Studio Code with ESP32 IDF 4.2
Windows 8.1

Logs from serial monitor after connecting:
I (43810) http_server: POST /connect.json
I (43810) http_server: ssid: vault05, password: XXXXXXXXXXXXXXX22
I (43810) wifi_manager: MESSAGE: ORDER_CONNECT_STA
I (44020) dns_server: Replying to DNS request for android.prod.cloud.netflix.com from 10.10.0.2
I (45310) http_server: GET /status.json
I (45470) http_server: GET /status.json
I (46620) wifi_manager: WIFI_EVENT_STA_CONNECTED
I (47620) esp_netif_handlers: sta ip: 192.168.50.219, mask: 255.255.255.0, gw: 192.168.50.1
I (47620) wifi_manager: IP_EVENT_STA_GOT_IP
I (47620) wifi_manager: WM_EVENT_STA_GOT_IP
I (47630) wifi_manager: Set STA IP String to: 192.168.50.219
I (47630) wifi_manager: About to save config to flash
I (50620) main: free heap: 204548
I (60620) main: free heap: 204548
I (70620) main: free heap: 204548
I (80620) main: free heap: 204548
I (90620) main: free heap: 204548
I (100620) main: free heap: 204548
I (110620) main: free heap: 204548
I (120620) main: free heap: 204548
I (130620) main: free heap: 204548
I (140620) main: free heap: 204548
I (150620) main: free heap: 204548
I (160620) main: free heap: 204760
I (170620) main: free heap: 204760

[tonyp7]

Hello,

If you see the message
"I (47630) wifi_manager: About to save config to flash"

It means you have entered wifi_manager_save_sta_config. What happens once you reset your ESP?

[pawelc06]

Hi tonyp7,
As I wrote It reports "No saved wifi found on startup":
I (1520) http_server: Registering URI handlers
I (1520) wifi_manager: MESSAGE: ORDER_LOAD_AND_RESTORE_STA
I (1530) wifi_manager: No saved wifi found on startup. Starting access point.
I (1530) wifi_manager: MESSAGE: ORDER_START_AP
I (1550) wifi_manager: WIFI_EVENT_AP_START
I (1650) http_server: Registering URI handlers
I (1650) dns_server: DNS Server listening on 53/udp
I (10620) main: free heap: 209616

Certainly for some reason saving of configuration and further re-connection doesn't occur.
Also callback function is not invoked.
Do you know how to force verbose mode to have more logs from WiFi manager/IDF libraries?

Cheers,
Pawel

[pawelc06]

Additional information:
After adding some debugs in wifi_manager.c, I identified where it blocks:
if(wifi_manager_config_sta && nvs_sync_lock( portMAX_DELAY )){

function nvs_sync_lock doesn't return true so it seems it can't get NVS semaphore.
I would appreciate any hints for me for further troubleshooting...

Pawel

[tonyp7]

I could not reproduce your issue so I ran

idf.py erase_flash

to completely restart anew. Now I can see your issue.

You are right the mutex cannot be obtained... Which is extremely weird because nothing else is taking it. I am still checking wtf is going on

[tonyp7]

I found it...

On the first run, if your flash memory is brand new, wifi_manager locks the mutex but doesn't release it because nvs_open does not resolve (the namespace has not been created yet).

I tripped on my own synchronization API. Good job me. Thanks for the reporting.

Could you give a try to the master branch?

[pawelc06]

Hi Tony,
Thank you for your investigation and fixing the issue.
I pulled master with your recent commit and I can confirm it works fine now.
Great work!
I've recently moved to ESP32 IDF as I want to learn FreeRTOS programming and your project was exactly what I needed as a starting point for WiFi provisioning.

Looking forward for future development.
Pawel

[tonyp7]

Great to hear people moving with the idf and freeRTOS. It's an amazing environment.

you can checkout my other project https://github.com/tonyp7/esp32-nixie-clock which uses a lot more freeRTOS and esp-idf features