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NanoPi Neo 2 UART (TTL) connection
Posted: Thu Oct 10, 2019 11:46 am
by koval
Hello,
I have NanoPi Neo 2 and I want connect my USB-TTL adapter to UART debug port.
What is logic levels for Rx&Tx? 3.3 V or 5 V ?
What speed should I tried for connection? 9600 or 115.200 ?
Re: NanoPi Neo 2 UART (TTL) connection
Posted: Thu Jan 02, 2020 1:51 pm
by koval
I found that correct TTL is 3.3 V and speed 9600.
But when I connected, nothing printed in terminal.
Any suggestion ?
Re: NanoPi Neo 2 UART (TTL) connection
Posted: Thu Jan 02, 2020 6:27 pm
by guidol
koval wrote:
I found that correct TTL is 3.3 V and speed 9600.
But when I connected, nothing printed in terminal.
Any suggestion ?
the debug-port of the Neo2 has 5V and the right speed is 115.200
Re: NanoPi Neo 2 UART (TTL) connection
Posted: Fri Jan 03, 2020 9:59 am
by koval
guidol wrote:koval wrote:
I found that correct TTL is 3.3 V and speed 9600.
But when I connected, nothing printed in terminal.
Any suggestion ?
the debug-port of the Neo2 has 5V and the right speed is 115.200
Hm, very interesting. Thank you for info. I will try to check with new settigns...
Re: NanoPi Neo 2 UART (TTL) connection
Posted: Fri Jan 17, 2020 10:00 am
by koval
guidol wrote:koval wrote:
I found that correct TTL is 3.3 V and speed 9600.
But when I connected, nothing printed in terminal.
Any suggestion ?
the debug-port of the Neo2 has 5V and the right speed is 115.200
Checked with your settings and it works!
Thank you so much!
Re: NanoPi Neo 2 UART (TTL) connection
Posted: Sat Jan 18, 2020 3:30 am
by v8dave
The debug port provides 5V but the actual voltage levels for the RX and TX lines are 3.3V. There are current limiting protection resistors inline but best to use 3.3V levels. VCC_IO is wired to 3.3V in the schematic. The baud rate is likely why you didn't see anything.