Problems with UART #186
Description
I am unable to set up UART with my board. My code runs with no errors, but no signal shows on the oscilloscope - it's 100% a voltage low. The "Serial is open!" message does show in the console. This time, invoking the script with sudo does not help. I've also tried to open a terminal with minicom to view the output for the tty. Here's my test code:
import Adafruit_BBIO.UART as UART
import serial
UART.setup("UART1")
ser = serial.Serial(port = "/dev/ttyO1", baudrate=9600)
ser.close()
ser.open()
if ser.isOpen():
print "Serial is open!"
ser.write("Hello World!")
ser.close()
I've also tried the following experiment.
#first terminal window:
minicom -b 9600 -D /dev/ttyO1
#second terminal window:
minicom -b 9600 -D /dev/ttyO2
#now type in one terminal and press enter. Expect to view characters in second window.
No matter what I do, no data is sent over UART. Any suggestions or ideas? Here's the state of my board.
debian@beaglebone:/var/lib/cloud9/senior_design$ apt-get -v
apt 1.4.8 (armhf)
Supported modules:
*Ver: Standard .deb
*Pkg: Debian dpkg interface (Priority 30)
Pkg: Debian APT solver interface (Priority -1000)
Pkg: Debian APT planner interface (Priority -1000)
S.L: 'deb' Debian binary tree
S.L: 'deb-src' Debian source tree
Idx: Debian Source Index
Idx: Debian Package Index
Idx: Debian Translation Index
Idx: Debian dpkg status file
Idx: Debian deb file
Idx: Debian dsc file
Idx: Debian control file
Idx: EDSP scenario file
Idx: EIPP scenario file
debian@beaglebone:/var/lib/cloud9/senior_design$ cat /etc/dogtag
cat /sys/devices/platform/bone_capemgr/slots
cat /boot/uEnv.txt
config-pin -q p9.14
uname -aBeagleBoard.org Debian Image 2017-10-17
debian@beaglebone:/var/lib/cloud9/senior_design$ cat /etc/debian_version
9.2
debian@beaglebone:/var/lib/cloud9/senior_design$ cat /proc/cmdline
console=ttyO0,115200n8 bone_capemgr.uboot_capemgr_enabled=1 root=/dev/mmcblk1p1 ro rootfstype=ext4 rootwait coherent_pool=1M net.ifnames=0 quiet
debian@beaglebone:/var/lib/cloud9/senior_design$ cat /sys/devices/platform/bone_capemgr/slots
cat: /sys/devices/platform/bone_capemgr/slots: No such file or directory
debian@beaglebone:/var/lib/cloud9/senior_design$ cat /boot/uEnv.txt
#Docs: http://elinux.org/Beagleboard:U-boot_partitioning_layout_2.0
uname_r=4.14.0-rc7-ti-r6
#uuid=
#dtb=
###U-Boot Overlays###
###Documentation: http://elinux.org/Beagleboard:BeagleBoneBlack_Debian#U-Boot_Overlays
###Master Enable
enable_uboot_overlays=1
###
###Overide capes with eeprom
#uboot_overlay_addr0=/lib/firmware/<file0>.dtbo
#uboot_overlay_addr1=/lib/firmware/<file1>.dtbo
#uboot_overlay_addr2=/lib/firmware/<file2>.dtbo
#uboot_overlay_addr3=/lib/firmware/<file3>.dtbo
###
###Additional custom capes
#uboot_overlay_addr4=/lib/firmware/<file4>.dtbo
#uboot_overlay_addr5=/lib/firmware/<file5>.dtbo
#uboot_overlay_addr6=/lib/firmware/<file6>.dtbo
#uboot_overlay_addr7=/lib/firmware/<file7>.dtbo
###
###Custom Cape
#dtb_overlay=/lib/firmware/<file8>.dtbo
###
###Disable auto loading of virtual capes (emmc/video/wireless/adc)
#disable_uboot_overlay_emmc=1
#disable_uboot_overlay_video=1
#disable_uboot_overlay_audio=1
#disable_uboot_overlay_wireless=1
#disable_uboot_overlay_adc=1
###
###PRUSS OPTIONS
###pru_rproc (4.4.x-ti kernel)
uboot_overlay_pru=/lib/firmware/AM335X-PRU-RPROC-4-4-TI-00A0.dtbo
###pru_uio (4.4.x-ti & mainline/bone kernel)
#uboot_overlay_pru=/lib/firmware/AM335X-PRU-UIO-00A0.dtbo
###
###Cape Universal Enable
enable_uboot_cape_universal=1
###
###Debug: disable uboot autoload of Cape
#disable_uboot_overlay_addr0=1
#disable_uboot_overlay_addr1=1
#disable_uboot_overlay_addr2=1
#disable_uboot_overlay_addr3=1
###
###U-Boot fdt tweaks...
#uboot_fdt_buffer=0x60000
###U-Boot Overlays###
cmdline=coherent_pool=1M net.ifnames=0 quiet
#In the event of edid real failures, uncomment this next line:
#cmdline=coherent_pool=1M net.ifnames=0 quiet 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=
##enable Generic eMMC Flasher:
##make sure, these tools are installed: dosfstools rsync
#cmdline=init=/opt/scripts/tools/eMMC/init-eMMC-flasher-v3.sh
debian@beaglebone:/var/lib/cloud9/senior_design$ config-pin -q p9.14
P9_14 Mode: pwm
debian@beaglebone:/var/lib/cloud9/senior_design$ uname -a
Linux beaglebone 4.14.0-rc7-ti-r6 #1 SMP Mon Oct 30 17:10:41 UTC 2017 armv7l GNU/Linux