BK7238 - identical MAC address after flashing OpenBK firmware 1.18.247 and 1.18.248

@p.kaczmarek2

Hello

I am struggling with these thermometers on the BK7238 and a problem has arisen. Namely, I uploaded firmware 1.18.247 (also tested on 1.18.248) and both thermometers get the same MAC address (C8:47:8C:42:88:48).

Unfortunately the option to change the MAC address in the configuration does not work for this chip Ot disconnects the connection and that's the end of it....

UART2 console log attached change_ma..og.txt Download(24.82 kB)

In the web application the MAC shown is wrong (in the configuration it shows ok)




I've also read the RF Config section and it looks empty and restoring does nothing....




Any ideas how the MAC can be changed ?

We are working on it. The RF partition needs to be moved. Colleague @divadiow knows something more about this. We had a topic about it the other day, check on com and maybe I can find it myself....

M.in. test post: https://www.elektroda.com/rtvforum/topic4133895.html#21722611

Hello.

This post details the RF recovery procedure but still requires UART flashing: https://www.elektroda.com/rtvforum/topic4106397.html#21764525

I don't know what the ultimate solution is, but I do recall suggesting recently that maybe Easy Flasher should make a point of telling users to definitely backup BK7238 before flashing OBK and maybe even auto-restoring RF from backup automatically.

I'm not sure why the current OBK offset for RF on BK7238 does not align with Tuya's, but maybe it's already too late for a breaking change - BK7238 is already super popular, the BK7231 of 2026.

RF section on common, non-Tuya BK7238 is at 0x1E0000. On T1 - at 0x1E3000.
And unfortunately, that's where OBK stores it's flash vars (reboot count, etc.).
Implement dummy RF generation in web app?

insmod wrote:

Implement dummy RF generation in web app?

Indeed! Will add. I gated RF restore to be for chipset T, N only in vueoverhaul commits currently. Also, was considering restore function in web app of RF from real backup file

Can't we move away flash vars? On BK7238? It won't hurt, people won't lose much on update, just saved relays states, led state, etc? Hm? Or am I missing something.

Hi All, hoping for a solution long term as I have a similar issue but is there a way in the short term to change the MAC address with the initial openBeken firmware before downloading to the device with a different default value. Perhaps, wondering if the MAC var register for these BK7238 chips be optioned with an over write of mac C8:47:8C:42:88:48 as I also get the same MAC address (C8:47:8C:42:88:48) when burning a range of different devices. Perhaps knowing the register location and if this may be a quick work around to over write that area with something like Ltchiptool or similar. Alternatively if the original firmware write could have the default address changeable or the location for the MAC address, so that a manual over write of that memory area can be changed, that would address the short term issue. I understand variables area may be over written but MAC is probably more important than reboot count or similar. P.S. Great work and greatly appreciate the effort with openBeken.