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Android 5.1 UART problem

Posted: Sun Jul 30, 2017 3:18 pm
by sms1989

I have a NanoPi M2 and M3 work with Android 5.1 ...

I test example programs from GitHub (

but SerialPortDemo not working and said "Fail to open /dev/ttyAMA2!" (ttyAMA2 for UART 3) ...

in Android 4.4 error not appear but it's not working

how can i use UART in Android 5.1 or Android 4.4

Re: Android 5.1 UART problem

Posted: Fri Aug 04, 2017 8:20 am
by v8dave
I wonder if this is to do with policies as I see the same issue on my T3 and M3 boards running Android 5.1 when trying to use ttyUSB2 with a modem plugged in.

Try this from either ADB shell or from the UART as root (type su first)


That should disable the policies until the next boot. See if your serial port now works.