This board looks very similar like the Arduino Micro or the Adafruit Pro 
Trinket. What are the benefits of your board compared to them? Why 
re-invent the wheel again?

Is the datasheet of the CX552 only available in chinese?

I think the 1kB RAM is not enough for an average Arduino based 
application.

stefanus wrote:
> Is the datasheet of the CX552 only available in chinese?
>
> I think the 1kB RAM is not enough for an average Arduino based
> application.

The key is the ulta low cost of the chip.

The EEV Blog released a couple of videos about this chip and the effort 
the community put into building a development environment and reverse 
engineering some commands. Because, the documentation is mostly chinese 
and there are more or less no ressources availiable.

Thank you.

For hobby electronics, it does not matter if the MCU costs 10 cent or 
100 cent.

So for china this could be an interesting product. But I doubt that the 
rest of the world is interested as long the datasheet is not well 
translated.

dsun wrote:
> Users can simply write code in Arduino IDE and hit one button to flash
> the chip to get code running.

I like it.
But, as mentioned, we need an english data sheet.
And, considering how clumsy the Arduino implementation of STM blue pill 
is (delivered without Arduino USB boot loader, must be flashed 
beforehand by serial method, but who needs Arduino if he already can 
flash the chip in a much better way including fuses), I hope that this 
will work right out of the box.
An original Arduino installs it's driver upon first contact with the 
host systen. THATs the user friendlyness that Arduino stands for and 
made it popular.

stefanus wrote:
> But I doubt that the rest of the world is interested as long the
> datasheet is not well translated.

There are translated datasheets available for the ch554 and for the 
ch559.
I did the USB Part myself 
https://github.com/kprasadvnsi/CH559_Doc_English
Here we have a big thread about the WCH MCUs in German.
Beitrag "uC für 0,20€ CH552 / CH554 von WCH Billig Micro mit USB Funktion, Chip vorstellung"

Btw Aaron here did recently something similar

Thomas

Hi Denqing,

Why did you deleted the Youtube Comments from my Implementation of the 
CH55xDuino ?

Not so cool.

https://youtu.be/EMDJe7JQ76g

Hi Aaron,

I have no idea why it is invisible. But I really didn't delete it.

Here is the comment on my Youtube app. I don't know why it is invisible 
on your page. I can not see it on the regular youtube page either.

You can not build an Arduino Micro or the Adafruit Pro Trinket for less 
than $1 each. But this board you can.

Also, there is no fine pitch part on this board. The soldering is much 
easier.

Thank you Denqing for clarifying it.

Strange youtube censorship

Then forget about it :)