[Letux-kernel] LX16 & LX20

[H. Nikolaus Schaller]

Hi,
here is also a small update for LX16/LX20.

I had received 3 PCBs each for the LX16 v0.4 and for LX20 v0.1.

Well, the LX20 was planned a demo board - and it was not complete
in schematics and PCB layout. So the result is just a demonstrator
how it could look like. My plan for the V0.2 is to have power supply,
console UART, LEDs,µSD and USB properly connected. Then we can start
to add support to the LetuxOS kernel. And a v0.3 will then add the
missing functions like RasPi connector and ESP32.

Unfortunately the PCB or assembly quality for the LX16 boards wasn't
100% as expected :(

Two boards do not "poweroff". Something seems to be wrong with the
PWROUT pin stopping the 3.3V regulator. On the third board it works.
But there, the PCB manufacturer already reported a short of two
GPIOs (PB30&31 or I2C).

It was no problem to flash the ESP32 modules in circuit through the
letux-esp-flasher tool. But on one board there are only tx_errors.
The reason is a short of SD-D0 to GND... But it works on the two
other boards. Power supply and USB (client or power in) seem to
be ok. USB OTG/DRP are broken and behave strangely like on the
v0.3 boards. What I haven't tried is the SPI display.

So in summary each of the 3 LX16 has some issue(s). But the
combination shows that everything could work. So it is no more
a circuit or software issue but production quality.

This means that the gate to produce a bigger bunch of boards
and offering them in the Goldelico Shop is open.

And of course we should now get more kernel code upstream...

Best regards,
Nikolaus

PS: If anyone reading here is going to Embedded World, have a look
at booth 3A-318.