Power & Source of Big Ideas

"host not reachable" - Can't SSH - Nano Pi R1

Moderators: chensy, FATechsupport

Hello,

I was playing around with network settings trying to make armbian a router, but now I can't login via SSH.

armbian is installed to eMMC

Code: Select all

$ sudo arp-scan 192.168.0.1-192.168.3.1
[sudo] password for admin:
WARNING: Could not obtain IP address for interface enp3s0. Using 0.0.0.0 for
the source address, which is probably not what you want.
Either configure enp3s0 with an IP address, or manually specify the address
with the --arpspa option.
Interface: enp3s0, datalink type: EN10MB (Ethernet)
Starting arp-scan 1.9.5 with 769 hosts (https://github.com/royhills/arp-scan)
192.168.0.14    12:81:3b:15:76:9c       (Unknown)
192.168.2.1     12:81:3b:15:76:9c       (Unknown)
192.168.2.20    12:81:3b:15:76:9c       (Unknown)


ssh admin@192.168.0.14
ssh: connect to host 192.168.0.14 port 22: Network is unreachable


how to reset? or reflash eMMC? or boot off of SD card?

1. I tried flashing SD card with nanopi-r1_eflasher_friendlywrt_4.14_armhf, doesn't seem to boot from that
2. held reset button a long time, doesn't seem to do anything

tips?

i was trying to run before, walking.
so i guess i need a USB to TTL serial cable?

USB to TTL Serial Cable - Debug / Console Cable for Pi
https://www.friendlyarm.com/index.php?r ... uct_id=178
it says "Connect Matrix-USB2UART to NanoPi NEO/NEO Air/NEO2/NEO Plus2's serial Interface"

1. does this work with Nano Pi R1?
I see Nano Pi has "UART x1: 2.54mm pitch 4-pin-connector". I guess same size as this.
2. can i fix my problem from serial console - flash eMMC?

thank you
arkadi wrote:
1. does this work with Nano Pi R1?
I see Nano Pi has "UART x1: 2.54mm pitch 4-pin-connector". I guess same size as this.
2. can i fix my problem from serial console - flash eMMC?


1.) The NPI R1 (not the new R1S) has the same 2.54mm Pinout as the Neo/Neo2 - should work.
2.) maybe you dont need to reflash - you could login via TTL-serial and correct your network settings without using a network/SSH ;)
guidol wrote:
arkadi wrote:
2.) maybe you dont need to reflash - you could login via TTL-serial and correct your network settings without using a network/SSH ;)


that would be great. i am having trouble getting TTL-serial connection to work. maybe you have some pointers?

this is what i tried so far

1) plugged in USB to TTY cable previous mentioned, (sys light blinking 2 fast, pause seems OK)
2) entered "dmesg" command:

Code: Select all

[  842.464315] usb 1-2: new full-speed USB device number 5 using xhci_hcd
[  842.612942] usb 1-2: New USB device found, idVendor=067b, idProduct=2303, bcdDevice= 3.00
[  842.612950] usb 1-2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[  842.612955] usb 1-2: Product: USB-Serial Controller
[  842.612959] usb 1-2: Manufacturer: Prolific Technology Inc.
[  842.615428] pl2303 1-2:1.0: pl2303 converter detected
[  842.616434] usb 1-2: pl2303 converter now attached to ttyUSB0

3) entered "sudo setserial /dev/ttyUSB0"
/dev/ttyUSB0, UART: 16654, Port: 0x0000, IRQ: 0
4)entered "sudo minicom -s"
shows device offline, can't do anything
5)then tried "sudo screen /dev/ttyUSB0"
blank screen with cursor at top left
6) then I tried "sudo putty", serial connection with /dev/ttyUSB0, speed: 115200
it opens up a terminal window but it's blank and nothing happens.

i'm quite lost. i don't know how to connect to the Nano Pi with a serial cable. oh how i regret messing around with those network settings to make SSH un-accessible.

anybody have any troubleshooting tips?

info from statserial /dev/ttyUSB0

Code: Select all

Device: /dev/ttyUSB0

Signal  Pin  Pin  Direction  Status  Full
Name    (25) (9)  (computer)         Name
-----   ---  ---  ---------  ------  -----
FG       1    -      -           -   Frame Ground
TxD      2    3      out         -   Transmit Data
RxD      3    2      in          -   Receive  Data
RTS      4    7      out         1   Request To Send
CTS      5    8      in          1   Clear To Send
DSR      6    6      in          1   Data Set Ready
GND      7    5      -           -   Signal Ground
DCD      8    1      in          1   Data Carrier Detect
DTR     20    4      out         1   Data Terminal Ready
RI      22    9      in          1   Ring Indicator
arkadi wrote:
6) then I tried "sudo putty", serial connection with /dev/ttyUSB0, speed: 115200
it opens up a terminal window but it's blank and nothing happens.

i'm quite lost. i don't know how to connect to the Nano Pi with a serial cable. oh how i regret messing around with those network settings to make SSH un-accessible.

anybody have any troubleshooting tips?


If the serial window is blank you could try to press enter to get a login prompt if the device has booted up.
If nothing appears after pressing enter/return then you could could try to switch rx with tx - some adaptors use rx-tx/tx-rx and some rx-rx/tx-tx

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