UART-4 not transmitting (BB Green)

[Ded Sec]

Here is my BB info:

root@beaglebone:~# uname -a && cat /sys/devices/platform/bone_capemgr/slots

Linux beaglebone 4.1.15-ti-rt-r43 #1 SMP PREEMPT RT Thu Jan 21 20:13:58 UTC 2016 armv7l GNU/Linux

0: PF----  -1

 1: PF----  -1

 2: PF----  -1

 3: PF----  -1

 5: P-O-L-   0 Override Board Name,00A0,Override Manuf,BB-UART4

root@beaglebone:~/pyy# cat /boot/uEnv.txt

#Docs: http://elinux.org/Beagleboard:U-boot_partitioning_layout_2.0

uname_r=4.1.15-ti-rt-r43

##uuid=

#dtb=

##BeagleBone Black/Green dtb's for v4.1.x (BeagleBone White just works..)

##BeagleBone Black: HDMI (Audio/Video) disabled:

dtb=am335x-boneblack-emmc-overlay.dtb

##BeagleBone Black: eMMC disabled:

#dtb=am335x-boneblack-hdmi-overlay.dtb

##BeagleBone Black: HDMI Audio/eMMC disabled:

#dtb=am335x-boneblack-nhdmi-overlay.dtb

##BeagleBone Black: HDMI (Audio/Video)/eMMC disabled:

#dtb=am335x-boneblack-overlay.dtb

##BeagleBone Black: wl1835

#dtb=am335x-boneblack-wl1835mod.dtb

##BeagleBone Green: eMMC disabled

#dtb=am335x-bonegreen-overlay.dtb

cmdline=coherent_pool=1M quiet cape_universal=enable

#In the event of edid real failures, uncomment this next line:

#cmdline=coherent_pool=1M quiet cape_universal=enable video=HDMI-A-1:1024x768@60e

##Example v3.8.x

#cape_disable=capemgr.disable_partno=

#cape_enable=capemgr.enable_partno=

##Example v4.1.x

#cape_disable=bone_capemgr.disable_partno=

#cape_enable=bone_capemgr.enable_partno=

#capemgr.enable_partno=BB-DCAN1,BB-UART2

cape_enable=bone_capemgr.enable_partno=BB-DCAN1,BB-UART4

##Disable HDMI/eMMC (v3.8.x)

#cape_disable=capemgr.disable_partno=BB-BONELT-HDMI,BB-BONELT-HDMIN,BB-BONE-EMMC-2G

##Disable HDMI (v3.8.x)

#cape_disable=capemgr.disable_partno=BB-BONELT-HDMI,BB-BONELT-HDMIN

##Disable eMMC (v3.8.x)

#cape_disable=capemgr.disable_partno=BB-BONE-EMMC-2G

##Audio Cape (needs HDMI Audio disabled) (v3.8.x)

#cape_disable=capemgr.disable_partno=BB-BONELT-HDMI

#cape_enable=capemgr.enable_partno=BB-BONE-AUDI-02

##enable Generic eMMC Flasher:

##make sure, these tools are installed: dosfstools rsync

##cmdline=init=/opt/scripts/tools/eMMC/init-eMMC-flasher-v3.sh

uuid={removed_from_paste}

and here is what I've tried

SENDER       |    RECEIVER   |   Status

BB UART-4   >   Arduino         =  Fails

Arduino         >   BB UART-4   =  Success

I have tried to transmit from BB both in python (code below) as well after following setup:

stty -F /dev/ttyS4 9600
echo "test" > /dev/ttyS4
echo test > /dev/ttyS4
sudo echo "test" > /dev/ttyS4
sudo echo test > /dev/ttyS4

but nothing appears on Arduino side

I  have tested UARTs on Arduino   so they do get/read data, with 2 arduinos connected to eachother and it all works.

Tho transmitting from BB does not. I dont have any logic analyzer to verify BB side unfortunately :/

For additional info, heres my python2 script on BB:

root@beaglebone:~/pyy# cat ser.py

import time

import serial

ser = serial.Serial(

   port='/dev/ttyS4',

   baudrate=9600

)

ser.isOpen()

out=[]

while 1 :

       if ser.inWaiting() > 0:

               for c in ser.read():

                       if c != '\x02' and c != '\x06' and c != ' ':                    

                               out.append(c)

                               if c == '\n':

                                       cmd=''.join(map(str,out))

                                       print cmd

                                       if cmd=="quit\r\n":

                                               ser.close()

                                               print "closing..."

                                               exit

                                       ser.flushInput()

                                       ser.write("test")

                                       ser.write('test1\n\r')

                                       out=[]

And Arduino is set to read and transmit, Pins are correctly setup

#include <SoftwareSerial.h>

SoftwareSerial mySerial(10, 11); // RX, TX

int debug = 0;

void setup() {

  mySerial.begin(9600);

  Serial.begin(9600);

  pinMode(13,OUTPUT);

  mySerial.println("Hello, world?");

}

void loop() { // run over and over

  mySerial.listen();

  char nn = mySerial.read();

  if(nn > -1){

    Serial.println(nn,HEX);

    return;

  }
}

And here's the schematic:

Really thankful for guidance since ive probably fried UART-2 pins as i accidentaly had levelshifter A-side powered from 5V and UART-1 is occupied by can-tranceiver.