It says there quite clearly that the chip it’s based on is FT232H. Nowhere does it say CH340.
Take a look at the wiki for Rock 4. The wiki is now deprecated but what is written there should be roughly similar to how Rock 5 uart works.
https://wiki.radxa.com/Rockpi4/dev/serial-console#Reduce_serial_port_baudrate
I was reading this that is related to rock5b, is here I read about CH340 and I thought was a good one: https://docs.radxa.com/en/rock5/rock5b/low-level-dev/serial
At a certain point it tells something about kind of cables:
I was asking if in that document, the last phrase means that for the guide they used a CH340, is there when I read about that.
For what I understood:
Is what I understood correct?
I’ve been using CH340N as well as FTDI232 flawlessly with rockchip devices at 1.5 Mbps. My Rock 5 ITX is connected via a cheap CH340N (tiny board). My Odroid-M1 is connected via a CP2102N.
BTW, what you’re describing seriously sounds like a hardware issue somewhere:
Heat alone should not hang your board, it should just throttle. And this SoC should not heat in a significant way by just installing packages. Mine is running with a modest heat sink and builds software fine. However I would really take the power adapter track seriously, because these boards can jump from low power when idle to high power when running, and the power adapter must really follow. If the USB cable is not integrated into the power adapter, then please also try with another cable, as this is often the greatest source of trouble. That’s what makes the RPi4 adapter great BTW, the cable being integrated into it allows the voltage feedback to be taken at the outer connector so that it compensates for losses.
Another thing you can try is to play with minimal/maximal cpufreq. Check the cpufreq policies for CPU 4-7 (A76) and try to fix them to a low frequency (1GHz or so). They should not consume much. If you see that everything runs stable, it will exclude problems in other components. Then force the min and max frequency to cpuinfo_max_freq. If it quickly hangs, it could confirm an issue related to power. If it only takes a long time to hang, it could indicate a heating problem. But I strongly doubt it, again. Maybe you’ve been unlucky and ended up on a defective board (SoC, other components etc). But please verify the power path first. This board is stable. Mine had more than 100 days of uptime before I had a power outage that reset it.
I have plenty of those UART adapters,
Some of them work on specific ROCK board, and don;t work on different board.
The best result I have with newer version on CH340 chip which is CH343. It has few improvements, waveshare sells those in few variants, to choose from 
It is powered through the usb port, not from the board. If you directly connect this to a usb-port (no hub) then there is more than enough power on a normal usb port.
Thank you all for your responses, in this short and unlucky experience with radxa rock 5b I realized that probably all I want is my money back, I don’t agree that radxa offers something similar/better of raspberry, the main obstacle at the beginning, since there are no official kits is: what I need to buy to have a working solution?
And now I discover I still miss an important component to diagnose my board, UART cable.
I’m not a kind of person who surrenders immediately, in my digital adventures I also used gentoo linux for 4 years, contributing also to its documentation, but with gentoo, even with small/big issues, community and documentation will be there to make me solve it.
If from the reseller I can give all back, I will do it, I think is better for me to search for a device needs less work/time/patience to make it work, sold by amazon, which is better than other niche resellers for niche products, just to let you know, after issue email sent, 13 days ago, I’m still waiting for response.
My point is not that this community lacks something, for what I saw you have a lot of knowledge and will to help, the problem comes with material things: defective hardware, money, accessories, and I realized that I cannot count on resellers/producers in a decent way in this part of the planet.
This would be better also for you, because you will miss a unhappy member of community, and I really hope the information you gave to me may be useful for someone else.
Obviously if they decide to not refund me, I will need to try the uart cable in order to solve this.
Quoted text is not something that I said 
Indeed something is strange about powering UART adapters, they should be powered via usb and they should be off when disconnected from port. But there are some that somehow manage to get some power from RX/TX/GND and they light up power LED (not that bright).
Also there are some wireless UART adapters that You need to power from SBC.
There’s one thing in what you wrote that seems wrong to me.
If you had any hardware troubles with a Raspberry Pi, you would also need a serial console to diagnose it, so UART. And similarly to rock 5b, most people don’t buy them because they don’t expect it to fail, or have no need for a serial console. So this is not specific to Radxa at all.
The lack of console port is not specific to Radxa, I’ve been encouraging FriendlyELEC for years to add one to their devices. That costs around $0.30 and is the only way to recover from a failed kernel upgrade or a non-booting device. What SBC vendors often don’t catch is that on a PC, the BIOS uses the default display+keyboard so it’s always possible to adjust settings and/or device what OS to boot. On SBCs that’s generally not the case so your only luck is a serial console. Given the pain it is to have to open a device, find a compatible UART-USB adapter and try to connect it when you’re facing a problem, I really encourage serious vendors to always add one. SolidRun does it for example, I’ve had one on various boards ranging from ClearFog to LX2K and mcbin.
Really, it’s pretty cheap and avoids staying on a terribly bad experience once in a while. There’s no reason for not adding one all the time (and a physically accessible one, not just the 3-pin terminal inside the enclosure, I’m speaking about an externally accessible USB connector).
Hi all,
there are some news: luckily my reseller concluded like me that there should be a hardware defect on my board and we agreed that the right thing to do was to replace it.
I accepted this despite my original idea was to simply give it back, this time I’ll try to be more cautious as I can.
I think that, since I have got a new radxa 5b, there are no reasons to continue in this thread.
Completely agree. UART/DEBUG usb-c port should not take too much space and it will help everybody to diagnose most of problems. I hope RADXA E20C debug port is just that:
Is the new board working?
I still don’t know, I opened another topic to get advices since the beginning in this new adventure. I thought it was not good to continue here, since it is a brand new board and I hope a brand new story I want to start with maximum caution. Even if the previous one was a defective one, I don’t want to make any mistake.
New topic is this: Replaced radxa 5b: little by little
