What is wifi: ap_loss? Where is SYSTEM_EVENT_STA_DISCONNECTED?

[vonnieda]

Hi all,

Can someone tell me what "wifi: ap_loss" logged on the console means? I am getting this message once in a while when trying to connect to an AP that is not available, and when I do, I do not get a SYSTEM_EVENT_STA_DISCONNECTED event.

To expand: I'm trying to make sure I always maintain a WiFi connection. I have several networks configured and I loop through them, trying each one. Normally, when I call esp_wifi_connect() I soon get either SYSTEM_EVENT_STA_CONNECTED or SYSTEM_EVENT_STA_DISCONNECTED. But once in a while I see "wifi: ap_loss" and do not get SYSTEM_EVENT_STA_DISCONNECTED.

My ultimate goal is to know that if I call esp_wifi_connect() I get *something* to tell me that the connection has either succeeded or failed. Right now I cannot determine how to do that reliably. Is there a way?

Thanks,
Jason

[kolban]

Howdy Jason,
Unfortunately I have no technical knowledge to add but I would personally be dissapointed to make an esp_wifi_connect() API call and get no event back as a result. Some loose thoughts that might spark something in your mind.

1. Check the return code from the original call to esp_wifi_connect(). If this is anything other than ESP_OK then I would not expect an event to be returned. A failure to initiate the contract/protocol should mean that all bets are off.

2. In your event handler, have a go at logging every event that is returned. Just maybe we will see an event that is neither SYSTEM_EVENT_STA_CONNECTED or SYSTEM_EVENT_STA_DISCONNECTED.

Let us also sift to look through patterns where your scenario shows up. We will also want to validate that you are running the latest version of the ESP-IDF.

After performing the esp_wifi_connect() what does your logic do next? I want to validate that we aren't then doing something that could perturb the connection protocol/story.

[vonnieda]

Howdy Jason,
Unfortunately I have no technical knowledge to add but I would personally be dissapointed to make an esp_wifi_connect() API call and get no event back as a result. Some loose thoughts that might spark something in your mind.

1. Check the return code from the original call to esp_wifi_connect(). If this is anything other than ESP_OK then I would not expect an event to be returned. A failure to initiate the contract/protocol should mean that all bets are off.

2. In your event handler, have a go at logging every event that is returned. Just maybe we will see an event that is neither SYSTEM_EVENT_STA_CONNECTED or SYSTEM_EVENT_STA_DISCONNECTED.

Let us also sift to look through patterns where your scenario shows up. We will also want to validate that you are running the latest version of the ESP-IDF.

After performing the esp_wifi_connect() what does your logic do next? I want to validate that we aren't then doing something that could perturb the connection protocol/story.

Hi kolban,

Thank you for your response!

To answer your questions:

1. I check all return codes and none are errors.
2. I do log every event, and I also log the default case, just in case I miss something. There are no unhandled or unexpected events.

I am running IDF as of yesterday, Git hash: 2935e958fc4b43c90550364d76ae8f0a3cb8488d

Instead of describing my somewhat complicated connection process, I've produced a simple test case for this issue, attached below. I've run this on my custom hardware and on a WROVER-KIT-V3 and both produce the same results. I've included a README.md with details on the issue.

Thanks,
Jason