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: <https://lh3.googleusercontent.com/-a9nugFfE4JE/V1VtKBSVOKI/AAAAAAAALTY/GYgxvx2wPMIRtsqXuOtK0vPBdhqdFGHVgCLcB/s1600/Screen%2BShot%2B2016-06-06%2Bat%2B2.31.25%2BPM.png> 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. -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/c6b10e9f-18d8-4071-aa9c-31032f3153ae%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.