FriendlyELEC-Forum

I'm trying to use the debug UART of the Nano Pi M4.
I connect via PuTTy. I set correct COM number, speed 1500000, but all I see is garbage.
I was expecting the log of the system boot and be able to issue some commands after boot sequence is complete.
I installed latest FriendlyDesktop on SD card.

I'm not using the counterfeit Prolific USB-to-serial, the chip on my converter is PL2303TA (Windows 10 drivers work with this one with no need to downgrade).

What else can I do?

When I tried to change the speed to e.g. 1100000, I could type in all of the numbers 1-9, and top keyboard row letters (with occasional garbage).

inxpc wrote:
I'm trying to use the debug UART of the Nano Pi M4.
I connect via PuTTy. I set correct COM number, speed 1500000, but all I see is garbage.

When I tried to change the speed to e.g. 1100000, I could type in all of the numbers 1-9, and top keyboard row letters (with occasional garbage).

Where did you get the information about the speed of 1.500.000 or 1.100.000 Baud for the serial port?
I couldnt find the baudrate at http://wiki.friendlyarm.com/wiki/index.php/NanoPi_M4

Normally - the NanoPi and other boards Board I know - does use 115.200 Baud for the serial port.
The only other board was a Orane Pi i96 with 921.600 Baud (strange).

So - first try 115200 Baud and maybe XON/XOFF has handshake.

1.100.000 was just my experimenting.
the 1.500.000 is right on the page you put a link to:
It says:

Debug: one Debug UART, 4 Pin 2.54mm header, 3V level, 1500000bps

inxpc wrote:
1.100.000 was just my experimenting.
the 1.500.000 is right on the page you put a link to:
It says:

Debug: one Debug UART, 4 Pin 2.54mm header, 3V level, 1500000bps

OK - I didnt searched for DEBUG - only for "serial"

1.500.000 is a very high Baudrate and I also got problem with the most TTL-USB adapters with 921.600 Baud at the Orange Pi i96.

The only TTL-USB adapter I did get to work at this rate was a CP2102.

The original FriendlyARM adpater does use a CH340T which didnt workes on the i96 ;(

I tried to work with the M4 board through the DEBUG connector.
Everything works, but only at a speed of 1,500,000 bps. It is quite high and not ordinary speed.
What is used as a USB-TTL adapter:

1. - CH340G USB To TTL (UP in picture)
2. - CP2102 MICRO USB to TTL (DOWN in picture)
All adapters are ordered in China (Ali ...).
In general, I would like to reduce the speed to 115 200, since I think everyone will have adapters for these speeds.
What are the options for reducing the speed of the built-in TTL port for debugging?