I am trying to get an arduino to tell my computer what the state of it's relays is. And for some reason every time it sends a new string PuTTY leaves the horizontal position of the last text. This makes for a very ugly display.
I would like PuTTY to look like the arduino serial manager.
Here is what it looks like from the arduino serial manager
This is what it looks like in PuTTY
This is the code I am using to send to computer from arduino.
You could have set Implicit CR in every LF option from PuTTY's terminal options instead of changing every line termination in your code from \n to \r\n.
Probably you should use "\r\n" instead of "\n" at the end of lines.
Send \r\n instead of \n only as end-of-line marker. A lot of terminals (incl. Putty, Minicom) require it.
Related
I want to send an information to web server with arduino via sim800l.
AT+HTTPPARA=\"URL\",\"http://api.trackers.live/v3.0.0/TRCKR02B2AF359D19/40.35715122342342322432-36.077406243242342-1469134234/1212/021/16553"
When I want to send long url to web server,the program crashes.
Does sim800l has an url limit? or is there any possible way to send an url like this?
Yes, all modems have a limit in how many characters they accept on a command line. The V.250 specification says in chapter "5.2.1 Command line general format":
A command line is made up of three elements: the prefix, the body, and the termination character. ... The DCE shall be capable of accepting at least 40 characters in the body.
The prefix is the two characters "AT" or "at" and the termination character should be '\r', thus a modem (aka DCE, Data Circuit-terminating Equipment) is allowed to only accept as low as 43 characters on a command line.
Now the was majority of modem supports more, probably that 40 character limit was due to some old Hayes modem made in the 1970s. If sim800l has decent documentation it should say how many characters it support on a command line. If it has crappy documentation it will not say.
As always with AT command syntax question, the very first source to query should always be the manufacturer specific documentation for that particular modem. Failing that you can fall back to V.250 or 27.007 or 27.005.
I dont know about the limit but you can use a link shortener to shorten the link...
I am sending commands over a serial port from a Linux embedded device to some serial enabled firmware. For easy debugging and simplicity we are using ascii human-readable commands terminated by newlines. Is it appropriate to use canonical mode here, or is canonical mode usually reserved for interactive terminals? The examples I find online all use raw mode.
In particular, in canonical mode, how do I check without blocking if an entire line is available for reading.
according to Linux Serial Programming documentation :
This is the normal processing mode for terminals, but can also be useful for
communicating with other dl input is processed in units of lines, which means
that a read will only return a full line of input. A line is by default
terminated by a NL (ASCII LF), an end of file, or an end of line character. A
CR (the DOS/Windows default end-of-line) will not terminate a line with the
default settings.
Canonical input processing can also handle the erase, delete word, and
reprint characters, translate CR to NL, etc..
First
using canonical mode for serial communications is the best option, because we have Linux kernel support on data transmission and system handlers that will help to better reading serial text
Second
if you want to use canonical mode , make sure that you are using the right character for end of line in your device that sending data , other way you cannot use canonical feature
Is it appropriate to use canonical mode here, or is canonical mode usually reserved for interactive terminals?
Yes, you can use canonical mode, but you will need to configure the termios interface for your situation.
The default termios configuration is for an interactive terminal, so features such as echoing the input should be disabled.
Since your device is unlikely to send the backspace and delete characters, such features can be ignored.
The examples I find online all use raw mode.
Seems like there are some "experts" that are not aware that canonical mode for terminals exists.
See the comments to reading from serial port in c breaks up lines .
For an example of (blocking) canonical mode, see this answer (note that there's another "expert comment" telling the OP that he cannot read lines).
In particular, in canonical mode, how do I check without blocking if an entire line is available for reading.
You could use select().
The man page implies that a canonical read of a terminal device is supported:
The file descriptors listed in readfds will be watched to see if characters become available for reading (more precisely, to see if a read will not block ...)
When both fields of the timeval structure are zero, then select() will not block and returns immediately.
I have an Arduino hanging off /dev/ttyUSB1, communicating at 115kbaud. The statements below work fine up to the 's next' method call, where Pharo hangs. The Arduino responds to the '99' command by sending a single character $1 back to the computer. If I pull out the cable, the program continues and s contains the character $1 just like it should, but not until I pull out the cable. So it's my impression that 's next' does not return after it reads just a single byte (ok, sure, there's nothing that says it should return after reading a single byte). How do I read a single byte from a stream in Pharo? Or how do I open a read/write byte stream? I haven't found anything in the source classes that seem to do this. I've tried setting the stream to ascii, to binary, to text, and it doesn't change the behavior.
s := FileStream oldFileNamed: '/dev/ttyUSB1'.
s readWrite.
s nextPutAll: '99'. "'99' is successfully received by Arduino"
s next. "hangs here"
s close.
Thanks for your help.
Take a look at the class side of FileStream. There you'll notice that you are getting a MultiByteStream (the concreteStream) when asking Filestream for an oldFileNamed:.
There can be a TextConverter or buffer involved. open:forWrite: of MultiByteStream is called, and that calls super. StandardFileStream>open:forWrite: calls enableReadBuffering.
You probably want to call disableReadBuffering on your stream.
There is an Arduino package that has all these issues solved, take a look at this repo:
http://ss3.gemstone.com/ss/Arduino.html
I am trying to paste a line; which is:
setenv -p STARTUP "ifconfig eth0 -auto;boot -z -elf 136.170.195.87:vmlinuz-nfs-7231b0-D183-NFS-DEBUG 'root=/dev/nfs nfsroot=136.170.195.87:/export/home/joshis1/vmlinuz-nfs-7231b0-D183/rootfs/nfs rw bmem=226M#30M ip=dhcp'"
When I try to copy the line in minicom, the line is not copied completely.
What should I do?
I have solved this by setting Character tx delay to 1ms.
Ctrl+A followed by z
select 't'
select 'f'
type '1'
and there you go!
Maybe you are running without line wrap on? I had a problem until I started invoking with "minicom -w". In the problem condition, output line content beyond screen width was lost, input line content wrapped to beginning of line.
If I'm not wrong you should exit minicom, start it again with "minicom -w".
Or even better, try using 'screen' instead of 'minicom'. I gave up minicom a long time ago in favor of screen. Once you get used to it, you'll never go back!. Chris Stratton was probably right: you're overrunning the target. There is no flow control in virtually all embedded targets. That said, I do these copy operations from screen all the time using screen to set u-boot environment variables, and never have any issues. Depends on your target, too!
Invoke screen something like this:
screen /dev/ttyUSB0 115200
Of course, the device node corresponding to your serial port will be different depending on your serial device. The example above is typical for Linux with a USB serial dongle. On my macbook, it usually comes up as something like this for the same serial dongle:
/dev/tty.usbserial
If you like vi, you'll love screen.
I do like the suggestion of this answer to use screen.
However, if you want to keep using minicom an option is to enable both Software flow control and Line wrap.
To enable Software flow control:
press Ctrl+A followed by o
go down to Serial port setup and enter it
press g to switch Software Flow Control to Yes (if not previously enabled)
press Esc and select Save setup as dfl if you want to permanently save the configuration
To enable Line wrap:
press Ctrl+A followed by o
go down to Screen and keyboard and enter it
press r to switch Line Wrap to Yes (if not previously enabled)
press Esc and select Save setup as dfl if you want to permanently save the configuration
Line wrapping can also be enabled by starting minicom with the -w option or by pressing Ctrl+A followed by w.
I am trying to send a serial command using my Arduino, but I can't find out how to replicate the Enter key. I've tried \r\n as well as \n and neither of those seem to do it.
I've tried the Arduino functions Serial.write() Serial.print() Serial.println() and none of those work either.
What can I use to replicate the Enter key?
Thank you
Try \r
It has the ASCII 0xD(13) and it's called Carriage Return
In general, it depends on the application that is processing the key press. From the keyboard, the typical scan code 0x1C is sent to the application for the Enter key (and 0x9C on release).
In PuTTY (related to OP's question here), it sends ASCII CR (carriage return) 0x0D only, even on Windows machines.