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glenn20 / micropython-espnow-images

A collection of pre-compiled micropython images (including espnow support) for the esp32 and esp8266.
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ESPNow.irecv() returns incorrect MAC address #3

Closed philwilkinson40 closed 3 years ago

philwilkinson40 commented 3 years ago

G'day Glenn, I have just started messing around with your espnow binaries and hit a problem.

software 20210511_espnow-g20_v115 firmware-esp8266-GENERIC.bin hardware is a bunch of Lolin Wemos D1 Minis

I am sending messages and receiving messages using your examples. The messages are sent and received fine.

However the ESPNow.irecv() returns a MAC bytearray of the sender as b'\xdeO"\x1c\x88l' however the MAC address of the sender is actually b'\xdcO"\x1c\x88l'

another example was b'\xdeO"\x1c\x8a\xc8' when the MAC address of the sender was actually b'\xdcO"\x1c\x8a\xc8'

the above indicates a single bit is in error.

glenn20 commented 3 years ago

Hi Phil,

I think you are seeing the sometimes confusing aspect of wifi on the ESP platform. The esp8266 (and esp32) have two wifi interfaces. In your case the network.WLAN(0).config('mac') will show the mac address of the STA_IF interface as b'\xdcO"\x1c\x88l' and network.WLAN(1).config('mac') will show the mac address of the AP_IF interface as b'\xdeO"\x1c\x88l'. On the ESP8266 the two interfaces always differ by 2 in the first octet - on the esp32 it is in the last octet.

I am guessing that your esp8266 has been configured so that the AP_IF interface is the active interface for sending espnow packets. If you want to change that, you can network.WLAN(1).active(False) ; network.WLAN(0).active(True). (Also - remember that the esp8266 remembers it's last wifi config when it reboots.)

If that is not the case, let me know and I will follow up the report in more detail.

philwilkinson40 commented 3 years ago

Beautiful! that does the trick. I can assure you there is no way I would have found that in the ESP docs, thanks @glenn20 ! Given I am possibly not the first or the last person to overlook that detail, is it worth putting a note in the docs?

glenn20 commented 3 years ago

Yes, it took me some time of reading and trial and error to work out the subtleties of networking on the esp platforms. I didn't want to have the micropython espnow docs be full of clarifications and explanations of general esp network management, but I find myself adding more and more such clarifications ;-). I will put something in the next version.

On Thu, 27 May 2021 at 20:01, Phil_Smurf @.***> wrote:

Beautiful! that does the trick. I can assure you there is no way I would have found that in the ESP docs, thanks @glenn20 https://github.com/glenn20 ! Given I am possibly not the first or the last person to overlook that detail, is it worth putting a note in the docs?

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