WiFi Monitor is always set to channel 1 when started

[hugokerstens]

I'm trying to monitor all different channels using my NodeMCU EPS8266 module. However, I quickly ran into the issue that whatever I tried, the monitored channel was always 1.

Looking into the source code, I found that upon starting the channel is set back to 1.

nodemcu-firmware/app/modules/wifi_monitor.c

Line 651 in 8181c3b

wifi_set_channel(1);

A workaround is to set the channel after starting the monitor, but that can be quite confusing. Even the provided example in the docs would not work, since the channel there is also set before starting the monitor.

https://nodemcu.readthedocs.io/en/master/en/modules/wifi_monitor/#example

I don't know if the call to wifi_set_channel is needed after changing into monitor mode, otherwise, the line can simply be removed.

Other solutions would be:

• Clearly specify this behaviour in the documentation
• Add an argument to wifi.monitor.start which specifies the channel

[pjsg]

You are absolutley right. The example should show the set channel happening after the call to start the monitor.

I had great difficulty in making the monitoring code work without crashing inside the SDK and I now can't recall whether the setchannel of 1 was necessary or not. I agree that it ought to be specified in the documentation.

Do you want to submit a pull request to fix the documentation?