The Serial console works for me without further modifications in both directions.
Are you connecting with the mapping described in the patch?
https://git.openwrt.org/?p=openwrt/openwrt.git;a=commit;h=95b0c07a618fe5fd93a26931152ced483bba143b
Yes, I'm using this mapping and I also can the data on the rx-pin with my oscilloscope. My thought was now that perhaps still somewhere something must be equipped.
@blocktrron Can you please have a look at your pcb if the marked pads are also open on yours?
The route from "my" Rx-Pin seems to end there.
I can have a look later this week. However, judging fro mthe pictures here suggests this is fine: https://boxmatrix.info/wiki/FRITZ!Box_7530
Other thought - which USB --> UART adapter are you using? I've found the cheap FTDI knockoffs not very reliable TX-wise in many cases - I've had much better experiences with a CP2102 based adapter.
Hmm... the board looks a little bit different than mine.
I don't use an USB -> UART adapter at all. I use a "real" ttyS0 / UART from my PC with a little MAX3221 adapter for the level shifting.
Is this device NEVER going to get a stable release due to DECT being impossible to support?
If so that seems an interesting stipulation as its been FAR more stable than my Archer C7 v2 was and that WAS in stable, when this is not.
The 7530 will be supported in the upcoming OpenWrt 19.07.0 release (and already is in snapshots), be aware that DECT support is unlikely to ever materialize and that the xDSL modem won't work for the time being either (this is more likely to become supported in the future than DECT, but it's also far from a done deal and will require significant efforts to get working - which might not happen either).
The 4040 might be a better option for running OpenWrt now, as it's basically the same hardware (for just over half the price of the 7530) - except for the functionality (xDSL modem/ DECT/ FXS) not supported in OpenWrt (yet) anyways.
That's good to know, I was just confused what qualifies a device to make the move over as its been in snapshots for quite some time now and performing great. (I use it most as an AP only but have used it as a 4G router too to link my phone into my pfSense router)
I got the 7530 for free from my ISP so cost was not an issue.
Is it possible to change back to AVM-stock firmware? The guy in this post:
had problems. I think, it could be because of repartition the flash. Anyone successful?
Thanks
Could it be it won't work with new FritzOS 7.12?
when i try to write uboot.bin to /dev/uboot0, it says this file doesn't exists. A ls -l into /dev:
no uboot0, no uboot1.
OK, last post solved. Downloaded newest snapshot and installation was without problems. Also seems i mad a mistake, the write has to be to uboot0, not /dev/uboot0.
I had the same problems. First the message 'Incompatible memory layout'. At some point I tried to load the image with eva_to_memory. That does not work either. So back to the AVM recovery tool. All at once mdt0 was flashed. Another try has flashed mtd1. So I've run the recovery tool several times it worked.
But hey ... I'll be back to OpenWrt immediately;)
Thank you. I want to know it only to be safe i could go back if i need the box' dsl-part. In the moment i'm happy with it under open-wrt. Use it as firewall behind a fritzbox 7390 for a separate network.
Great work! 
What's the current state of the VDSL modem?
Would it be possible to use the binary AVM VRX518 kernel module against the OpenWRT kernel for now?
What is the procedure to reset to openwrt default config?
Hi to every developer devote to this project. It's already september, i'm curious about how VRX518 supported now? Does it work now with the newest version 19.07.3? Thanks for kindness reply.
Hi to every developer devote to this project. It's already january, i'm curious about how VRX518 supported now? Does it work now with the newest version 19.07.6? Thanks for kindness reply.
So to everyone who'd like to see a working modem on the 7530:
Things are happening! Maybe some of you would also help with a donation. It looks like promising progress and don't we all want a capable OpenWRT router with a working modem? 
Hi, I would love to donate to support the DSL modem integration as well. I got OpenWRT running, but of course not the modem for now -.-
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