I need to use ttyS0 as serial communication in python script on my coral mini board, I disabled system service:
sudo systemctl stop systemd-logind
sudo systemctl stop serial-getty#ttyS0.service
But seems there still have output from Serial console in ttyS0 like:
IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
spidev spi0.0: SPI transfer timed out
I would like to know how to make the ttyS0 clean as no any other process using it, if its possible, better to do it in runtime.
Thanks!
Related
I'm writing a kernel from scratch in Rust for 64-bit ARM devices. For testing purpose, I use Qemu virt machine.
Currently, I'm able to write characters from guest to host console through UART. Now I would like to do the opposite, i.e. send characters from host console to guest UART port. Is there a way to do this? Should I add some arguments to Qemu?
I run Qemu virt machine with the following arguments:
qemu-system-aarch64 -M virt -cpu cortex-a57 -nographic -serial pty -S -kernel target/aarch64-unknown-none/debug/cortex-a57
It gives me a new pty that I can attach with screen /dev/pts/mypty. Then I run the program tapping c in Qemu console.
I would like to use the same pty (or a new one?) to write data to the guest.
QEMU always redirects both input and output for a guest UART to the same place; this is true of all of '-serial stdio', '-nographic' (which does an implicit '-serial mon:stdio') and '-serial pty'. So you don't need to do anything extra. If UART input is not working then the problem seems likely to be a bug in your guest code.
Just read the same TTY as Qemu redirects all input to the same place.
I'm trying to remote debug using gdbserver.
I connect my target device to my PC through USB port using this command to open terminal controlling my device :
minicom -D "/dev/ttyUSB0".
Now on my target device, I need to run gdbserver with this cmd:
gdbserver /dev/my_USB_serial_port my_Program.
However, I can't find ttyUSB0, all I got ís a bunch of ttyx(with x is a number) as below:
~ # /dev/tty
tty tty14 tty20 tty27 tty33 tty4 tty46 tty52 tty59 tty8
tty0 tty15 tty21 tty28 tty34 tty40 tty47 tty53 tty6 tty9
tty1 tty16 tty22 tty29 tty35 tty41 tty48 tty54 tty60 ttyS0
tty10 tty17 tty23 tty3 tty36 tty42 tty49 tty55 tty61 ttyS1
tty11 tty18 tty24 tty30 tty37 tty43 tty5 tty56 tty62
tty12 tty19 tty25 tty31 tty38 tty44 tty50 tty57 tty63
tty13 tty2 tty26 tty32 tty39 tty45 tty51 tty58 tty7
How could I find which one is the correct serial port of my USB port ?
Update 1: As Employed Russian mentioned in the answer, I got confused about the USB port but I still couldn't connect to gdbserver using his command.
However, I can't find ttyUSB0
You are confused -- of course you will not find ttyUSB0 on the target -- the target doesn't have anything plugged into its USB port.
On the target, you want to run gdbserver - my_Program &, then disconnect minicom, and finally use gdb and target remote /dev/ttyUSB0 on the host.
Make sure getty isn't running on the same serial port as gdbserver on the target.
If you've got an interactive shell with minicom, check the serial port (usually ttyS0) on the target that's connected to it. If it's ttyS0, you start gdbserver on some other port, and connect another FTDI cable from that port to a second USB port on your host.
This question is related to this, Cannot program ESP8266, but different settings.
I have a NodeMCU devkit v1, its comercial name is NodeMCU v2. I tried different setting to connect the devkit.
First the devkit has a usb-serial bridge (CP2102) and voltage adapter from 5v (USB) to 3.3v. So I connect the devkit with the machine via USB. The driver is installed correctly, and I can see the com, it is COM3.
After turning on the NodeMCU I can see a Wifi AI-THINKER-adfe21.
Then I tried with the nodemcu-flasher - WINDOWS.
Without any button or pin to ground. I press Flash in the flasher and stay Waiting MAC and the log says Begin Find ESP8266 as the question I told in the begin and the ESP's led (blue led) blinks.
Holding FLASH, press RESET, release FLASH. Still the same like 1.
Wire D3 (GPIO0) to GND. Same result
With ESPtool - LINUX - Trying these commands
python2 esptool.py --port /dev/ttyUSB0 read_mac
python2 esptool.py --port /dev/ttyUSB0 write_flash 0x00000 firmware.bin
Without any button or pin to ground. The output for the commands was Connecting... A fatal error occurred: Failed to connect to ESP8266
Holding FLASH, press RESET, release FLASH. Same
Wire D3 (GPIO0) to GND. Same result.
Via Arduino IDE, I installed the ESP8266 board and selected NodeMCU 1.0. The result to try upload some code -> warning: espcomm_sync failed error: espcomm_open failed
I tryed to connect the NodeMCU without the USB. Using an Arduino UNO, connecting like following... And I'm getting the same errors.
UNO | NodeMCU
5v -> Vin
GND -> GND
Rx -> Tx
Tx -> Rx
The last test I made, it is with Putty or Arduino SerialMonitor connect to the COM3 or /dev/ttyUSB0 and turning on the NodeMCU. I should see some characters or garbage if it in different baud rate. But I got nothing, the terminal is blank. I restart the NodeMCU, put it in Flash mode. No response.
Are there some solution, tip or trick to make it programmable?
PS: I know the NodeMCU is in Flash mode because its wifi disappear.
EDIT:
I discovered something.
I just connected the NodeMcu with a mobile charger and connect the D0 to Serial ground and D3 to Serial Rx. On the putty with 115200 Baudrate, I'm able to get the following code on reset.
node : sta(mac address) + softAP(mac address)
add if0
add if1
dhcp server start:(ip:192.168.4.1, mask:255.255.255.0,gw:192.168.4.1)
bcn 100
I have been working with both the node-mcu flasher and the esptool.
First in the esptool yo should use more parameter in the call. Use something like this
python esptool.py -p SERIAL_PORT_NAME --baud 9600 write_flash --flash_size=8m 0 firmware-combined.bin
Be careful with the baudrate, i always use 9600.
If you prefer using the windows program you should only connect the ESP8266 through usb and dont connect any other pin. If it still gives you problems you should check that u have installed the com ports.
Good Luck
if you are using esptool (either in Linux or windows), you should include -fm and -fs inside the esptool command. There will be no response if you did not include those 2 parameter even though it show successfully upload. you can refer the detail in this youtube tutorial or its description for flashing firmware in nodemcu V2 or v1.0.
esptool.py --port [serial-port-of-ESP8266] write_flash -fm [mode] -fs [size] 0x00000 [nodemcu-firmware].bin
Tutorial on how to flash firmware using esptool(windows):
https://www.youtube.com/watch?v=MHrm7axsImI
cheers!
Maybe you can try this setting.
$sudo esptool.py -p /dev/ttyUSB0 --baud 115200 write_flash -fs 16m -fm qio -ff 0x00000 firmware.bin
I have set up a ITEAD sim900 GSM module to interface with raspberry pi. I believe I have established a gprs connection to AT&T though wvdial as I get these results.
--> WvDial: Internet dialer version 1.61
--> Initializing modem.
--> Sending: AT+CGDCONT=1,"IP","Broadband"
AT+CGDCONT=1,"IP","Broadband"
OK
--> Modem initialized.
--> Sending: ATDT*99#
--> Waiting for carrier.
ATDT*99#
CONNECT
--> Carrier detected. Starting PPP immediately.
--> Starting pppd at Thu Aug 14 05:49:20 2014
--> Pid of pppd: 2794
I have been looking all over the internet for some answers to a few questions that I have, but I can't seem to find any. Any help with the following questions will be greatly appreciated! Thanks!
I have three questions, and some may be stupid as I am VERY new to this field.
Am I actually connected to AT&T's GPRS network?
How can I make this module (serial port /dev/ttyAMA0) my default internet connection? What I mean is I want all internet traffic routed through this modem(web surfing, email etc.). I am connected to the Raspberry via ssh so I have to have either ethernet or wifi active to access the computer--I am currently using ethernet. After I connect through wvdial in the way shown above, and disable all other internet sources I have no access. It seems to still be looking to the active ethernet port for data(I could be wrong).
For my project I need to have the sim900 modem as the internet access point, but I also need to be able to connect to a LAN via wifi that has no internet access. Is this possible?
Finally i got the ( raspberrypi + ppp + gprs/gsm-modem ) working.
Some notes before start:
Make sure the power supply you used for raspberrypi is exact 5V and it can provide at-least 2A current without voltage drop-out.The SIM900 power-source must be 3.3V 2A
Set the SIM900 baud rate to 115200 via: AT+IPR=115200
Check the modem serial peripheral via: $ screen /dev/ttyAMA0 115200 type AT<enter> it will echo: OK. Hit ctrl+a k y to exit.
/etc/ppp/options-mobile
ttyAMA0
115200
lock
crtscts
modem
passive
novj
defaultroute
replacedefaultroute
noipdefault
usepeerdns
noauth
hide-password
persist
holdoff 10
maxfail 0
debug
Create the /etc/ppp/peers directory:
$ mkdir /etc/ppp/peers
$ cd /etc/ppp/peers
/etc/ppp/peers/mobile-auth
file /etc/ppp/options-mobile
user "your_usr"
password "your_pass"
connect "/usr/sbin/chat -v -t15 -f /etc/ppp/chatscripts/mobile-modem.chat"
/etc/ppp/peers/mobile-noauth
file /etc/ppp/options-mobile
connect "/usr/sbin/chat -v -t15 -f /etc/ppp/chatscripts/mobile-modem.chat"
Create the /etc/ppp/chatscripts directory:
$ mkdir /etc/ppp/chatscripts
/etc/ppp/chatscripts/mobile-modem.chat
ABORT 'BUSY'
ABORT 'NO CARRIER'
ABORT 'VOICE'
ABORT 'NO DIALTONE'
ABORT 'NO DIAL TONE'
ABORT 'NO ANSWER'
ABORT 'DELAYED'
REPORT CONNECT
TIMEOUT 6
'' 'ATQ0'
'OK-AT-OK' 'ATZ'
TIMEOUT 3
'OK' #/etc/ppp/chatscripts/pin
'OK\d-AT-OK' 'ATI'
'OK' 'ATZ'
'OK' 'ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0'
'OK' #/etc/ppp/chatscripts/mode
'OK-AT-OK' #/etc/ppp/chatscripts/apn
'OK' 'ATDT*99***1#'
TIMEOUT 30
CONNECT ''
/etc/ppp/chatscripts/my-operator-apn
AT+CGDCONT=1,"IP","<apn-name>"
/etc/ppp/chatscripts/pin.CODE
AT+CPIN=1234
/etc/ppp/chatscripts/pin.NONE
AT
/etc/ppp/chatscripts/mode.3G-only
AT\^SYSCFG=14,2,3fffffff,0,1
/etc/ppp/chatscripts/mode.3G-pref
AT\^SYSCFG=2,2,3fffffff,0,1
/etc/ppp/chatscripts/mode.GPRS-only
AT\^SYSCFG=13,1,3fffffff,0,0
/etc/ppp/chatscripts/mode.GPRS-pref
AT\^SYSCFG=2,1,3fffffff,0,0
The SYSCFG line in the mode.* files is device-dependent, and likely Huawei-specific, So You may use the mode.NONE file if your modem is
SIM900.
*
/etc/ppp/chatscripts/mode.NONE
AT
Make some symbolic links:
$ ln -s /etc/ppp/chatscripts/my-operator-apn /etc/ppp/chatscripts/apn
$ ln -s /etc/ppp/chatscripts/mode.NONE /etc/ppp/chatscripts/mode
$ ln -s /etc/ppp/chatscripts/pin.NONE /etc/ppp/chatscripts/pin
If you have to enter credentials use mobile-auth
$ mv provider provider.example
$ ln -s /etc/ppp/peers/mobile-noauth /etc/ppp/peers/provider
Check syslog in another console:
$ tail -f /var/log/syslog | grep -Ei 'pppd|chat'
Finally issue the pon command to see the result:
$ pon
The base instruction : https://wiki.archlinux.org/index.php/3G_and_GPRS_modems_with_pppd
Is it possible to pipe serial console output to a file or a buffer or some virtual or pseudo device (in /dev)?
The Kernel command line has in startup at this point "console=null,115200".
(Normally it has "console=ttyS0,115200" - my requirement is: if "console=null,115200", should the output go to some other place than ttyS0, e.g. a virtual or pseudo device or to a file/buffer)
Maybe somebody know if there is good solution available?
Thanks a lot in advance!
There are two ways that I am aware of :-
First way :-
get ttylog from sourceforge :-
http://sourceforge.net/projects/ttylog/files/latest/download
Fire the below command:-
nohup ttylog -b 115200 -d /dev/ttyS0 > log.txt
this will then show you the PID of the process that is running, you now need to disown that PID so it doesn't get killed when you log out. Note that 115200 is the serial port speed/baud rate you configured grub for on the box you are monitoring.
Second way :-
Setup a serial console from system under test to some other linux/windows box. In case of linux install minicom and set minicom to listen on the serial port define in grub of system under test. Save that as dfl. You are good to go for more info :-
https://www.kernel.org/doc/Documentation/serial-console.txt