1

I am new to RPi's so bear with me please:

I am trying to log in to the Pi0 console via sudo screen /dev/ttyUSB0 115200 but I just get a blank screen.

Ouput of dmesg | grep tty:

[    0.000000] Kernel command line: 8250.nr_uarts=1 bcm2708_fb.fbwidth=1184 bcm2708_fb.fbheight=624 bcm2708_fb.fbswap=1 vc_mem.mem_base=0x3ec00000 vc_mem.mem_size=0x40000000  dwc_otg.lpm_enable=0 console=tty1 console=ttyAMA0,115200 root=/dev/mmcblk0p7 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait splash plymouth.ignore-serial-consoles
[    0.001203] console [tty1] enabled
[    0.997729] 3f201000.serial: ttyAMA0 at MMIO 0x3f201000 (irq = 87, base_baud = 0) is a PL011 rev2
[    1.961145] console [ttyAMA0] enabled
[   26.554073] usb 1-1.2: pl2303 converter now attached to ttyUSB0

So I can see that the adapter is connected and recognized.

The contents of the RPi 3 config.txt are below:

# For more options and information see
# http://rpf.io/configtxt
# Some settings may impact device functionality. See link above for details

# uncomment if you get no picture on HDMI for a default "safe" mode
#hdmi_safe=1

# uncomment this if your display has a black border of unused pixels visible
# and your display can output without overscan
#disable_overscan=1

# uncomment the following to adjust overscan. Use positive numbers if console
# goes off screen, and negative if there is too much border
#overscan_left=16
#overscan_right=16
#overscan_top=16
#overscan_bottom=16

# uncomment to force a console size. By default it will be display's size minus
# overscan.
#framebuffer_width=1280
#framebuffer_height=720

# uncomment if hdmi display is not detected and composite is being output
hdmi_force_hotplug=1

# uncomment to force a specific HDMI mode (this will force VGA)
hdmi_group=1
hdmi_mode=4

# uncomment to force a HDMI mode rather than DVI. This can make audio work in
# DMT (computer monitor) modes
#hdmi_drive=2

# uncomment to increase signal to HDMI, if you have interference, blanking, or
# no display
#config_hdmi_boost=4

# uncomment for composite PAL
#sdtv_mode=2

#uncomment to overclock the arm. 700 MHz is the default.
#arm_freq=800

# Uncomment some or all of these to enable the optional hardware interfaces
dtparam=i2c_arm=off
#dtparam=i2s=on
dtparam=spi=off

# Uncomment this to enable the lirc-rpi module
#dtoverlay=lirc-rpi

# Additional overlays and parameters are documented /boot/overlays/README

# Enable audio (loads snd_bcm2835)
dtparam=audio=on

# NOOBS Auto-generated Settings:
hdmi_force_hotplug=1
start_x=1
gpu_mem=128
enable_uart=1
#dtoverlay=w1-gpio

# My Settings
# dtoverlay=pi3-disable-bt

The contents of the RPi 3 cmdline.txt are below:

dwc_otg.lpm_enable=0 console=tty1 console=serial0,115200 root=/dev/mmcblk0p7 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait splash plymouth.ignore-serial-consoles

The contents of the RPi 0 config.txt are below:

# For more options and information see
# http://www.raspberrypi.org/documentation/configuration/config-txt.md
# Some settings may impact device functionality. See link above for details

# uncomment if you get no picture on HDMI for a default "safe" mode
#hdmi_safe=1

# uncomment this if your display has a black border of unused pixels visible
# and your display can output without overscan
#disable_overscan=1

# uncomment the following to adjust overscan. Use positive numbers if console
# goes off screen, and negative if there is too much border
#overscan_left=16
#overscan_right=16
#overscan_top=16
#overscan_bottom=16

# uncomment to force a console size. By default it will be display's size minus
# overscan.
#framebuffer_width=1280
#framebuffer_height=720

# uncomment if hdmi display is not detected and composite is being output
#hdmi_force_hotplug=1

# uncomment to force a specific HDMI mode (this will force VGA)
#hdmi_group=1
#hdmi_mode=1

# uncomment to force a HDMI mode rather than DVI. This can make audio work in
# DMT (computer monitor) modes
#hdmi_drive=2

# uncomment to increase signal to HDMI, if you have interference, blanking, or
# no display
#config_hdmi_boost=4

# uncomment for composite PAL
#sdtv_mode=2

#uncomment to overclock the arm. 700 MHz is the default.
#arm_freq=800

# Uncomment some or all of these to enable the optional hardware interfaces
#dtparam=i2c_arm=on
#dtparam=i2s=on
#dtparam=spi=on

# Uncomment this to enable the lirc-rpi module
#dtoverlay=lirc-rpi

# Additional overlays and parameters are documented /boot/overlays/README

# Enable audio (loads snd_bcm2835)
dtparam=audio=on

dtoverlay=dwc2
enable_uart=1

The contents of the RPi 0 cmdline.txt are below:

dwc_otg.lpm_enable=0 console=serial0,115200 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait

Using linux-serial-test (https://github.com/cbrake/linux-serial-test) command linux-serial-test -s -e -p /dev/ttyUSB0, I get the following:

Linux serial test app
/dev/ttyUSB0: count for this session: rx=0, tx=64512, rx err=0
/dev/ttyUSB0: count for this session: rx=0, tx=133632, rx err=0

I guess meaning that no data is being received by the RPi 3.

Then contents of my /dev directory are below:

autofs           loop4               ram2     tty15  tty43      uinput
block            loop5               ram3     tty16  tty44      urandom
bsg              loop6               ram4     tty17  tty45      usb
btrfs-control    loop7               ram5     tty18  tty46      v4l
bus              loop-control        ram6     tty19  tty47      vchiq
cachefiles       mapper              ram7     tty2   tty48      vcio
char             media0              ram8     tty20  tty49      vc-mem
console          mem                 ram9     tty21  tty5       vcs
cpu_dma_latency  memory_bandwidth    random   tty22  tty50      vcs1
cuse             mmcblk0             raw      tty23  tty51      vcs2
disk             mmcblk0p1           rfkill   tty24  tty52      vcs3
fb0              mmcblk0p2           sda      tty25  tty53      vcs4
fd               mmcblk0p5           sda1     tty26  tty54      vcs5
full             mmcblk0p6           sda2     tty27  tty55      vcs6
fuse             mmcblk0p7           serial   tty28  tty56      vcs7
gpiochip0        mqueue              serial0  tty29  tty57      vcsa
gpiochip1        net                 serial1  tty3   tty58      vcsa1
gpiomem          network_latency     sg0      tty30  tty59      vcsa2
hidraw0          network_throughput  shm      tty31  tty6       vcsa3
hidraw1          null                snd      tty32  tty60      vcsa4
hidraw2          ppp                 stderr   tty33  tty61      vcsa5
hidraw3          ptmx                stdin    tty34  tty62      vcsa6
hwrng            pts                 stdout   tty35  tty63      vcsa7
initctl          ram0                tty      tty36  tty7       vcsm
input            ram1                tty0     tty37  tty8       vhci
kmsg             ram10               tty1     tty38  tty9       video0
log              ram11               tty10    tty39  ttyAMA0    watchdog
loop0            ram12               tty11    tty4   ttyprintk  watchdog0
loop1            ram13               tty12    tty40  ttyS0      zero
loop2            ram14               tty13    tty41  ttyUSB0
loop3            ram15               tty14    tty42  uhid

So I can't say that I fully understand the difference between serial0, serial1, ttyAMA0, ttyUSB0 maybe that's where my error is coming from?

I saw this and tried it but to no avail: Pi 3 Boot with UART console

Before I get too crazy trying to change everything, I'd appreciate some guidance from someone more experienced please. Thanks in advance for any/all help!!

EDIT:

Adapter link: https://www.amazon.com/gp/product/B00QT7LQ88/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1

Photo of setup

UPDATE:

  • I can verify that minicom -b 115200 -o -D/dev/< connection > only opens a connection for serial1 and ttyUSB0 though I'm not sure, yet, how to access a console in minicom (THIS IS NO LONGER TRUE FOR SOME REASON)

  • I plugged in the USB to my mac after downlaoding drivers etc, but same result. Wondering if OS on Pi0 is not initiliazed? https://villagescience.org/running-raspberry-pi-usb-serial-ttl-adapter/

  • Could issue have anything to do with Serial Getty Service?

  • The other problem is that because it seems there are several variables involved, the suggestion of someone to change a single variable may not be wrong, but it may also not yield a solution. (Just saying so that if I say that I've have tried something, that doesn't mean that I tried it in the right combination - and at this point I've tried so many it is hard to remember)

  • For a start you should detail HOW the USB adapter is connected. You SHOULD NOT need to change ANYTHING on the Pi3. – Milliways Apr 16 '18 at 23:59
  • I have it set up exactly as depicted here: github.com/Fmstrat/diy-ipmi#troubleshooting – Sterling Butters Apr 17 '18 at 4:29
  • Just look for the picture ^ (also, the only thing I guess I really changed on the RPi3 was to enable the serial interface in raspi-config). Should it be disabled? – Sterling Butters Apr 17 '18 at 4:31
  • A photo of your set up is needed. – joan Apr 17 '18 at 7:59
  • In your cmdline.txt, you have multiple console=. I believe only the last one counts. What is the use of dtoverlay=dwc2? I Last but not least, not all adapters work, very important they have the right chip. – Gerard H. Pille Apr 17 '18 at 12:14

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