sniff

Elixir Serial Port NIF

Notice: sniff focuses in the native interface to serial ports. For higher level serial port access see baud.

Installation

Add sniff to your list of dependencies in mix.exs:

def deps do
  [{:sniff, "~> 0.1.7"}]
end

Usage

#this echo sample requires a loopback plug
#supported config combinations {8,7}{N,E,O}{1,2}
iex(1)> {:ok, nid} = Sniff.open("/dev/ttyUSB0", 9600, "8N1")
{:ok, #Reference<0.83505167.3498704899.238160>}
iex(2)> Sniff.write(nid, "hello")
:ok
iex(3)> Sniff.read(nid)
{:ok, "hello"}
iex(4)> Sniff.close(nid)
:ok

Test

# test with socat ttys
./test.sh
# test with custom ttys (null modem)
export TTY0="/dev/ttyUSB0"
export TTY1="/dev/ttyUSB1"
mix test
#in Windows
#requires COM98/COM99 com0com ports
test.bat

Development

Windows

Install Visual C++ 2015 Build Tools by one of the following methods:

• Download and install visualcppbuildtools_full.exe
• With Chocolatey choco install VisualCppBuildTools.

From the Windows run command launch cmd /K c:\Users\samuel\Desktop\sniff\setenv.bat adjusting your code location accordingly.

Ubuntu

Give yourself access to serial ports with sudo gpasswd -s samuel dialout. Follow the official Elixir installation instructions and install build-essential erlang-dev as well.

MacOS

Give yourself access to serial ports with sudo dseditgroup -o edit -a samuel -t user wheel.

Roadmap

Future

• Binary distro to avoid devenv setup
• Cleanup windows compilation warnings

0.1.8

• Support {8,7}{N,E,O}{1,2} configs

0.1.7

• Auto close monitor and test
• Migrated to elixir_make

0.1.6

• Fixed raw mode to avoid byte 15 swallow in macos
• Testing with fake socat ttys
• Requires full posix serial port path
• Pass test serial port thru environment variables

0.1.5

• Added O_NONBLOCK for MacOS file open.
• Tests confirmed to pass on linux.
• Upgraded ex_doc to compile with latest elixir
• Test serial port names detection on unixes
• Fixed binary leak when serial_read fails
• Separated darwin and linux baudrate files

0.1.4

• Handle spaces in Windows build path

0.1.3

• Document Windows dependencies
• BAT to launch windows dev environment
  • A bat to call env.bat and cd back to code folder is provided
  • must be executed from Windows run command (no double click)
• Ensure native library can be loaded on first compile
  • First deps.get && compile works fine
  • Second compile works fine
  • clean && compile fails to load NIF library
• Ensure native library can be loaded from IEX
  • Tested on OSXElCapitan/Ubuntu16.10/Windows10
• Ensure native library can be loaded when used as dependency from IEX
  • Tested on OSXElCapitan/Ubuntu16.10/Windows10
• Pass the ERTS_HOME to unix makefiles
  • Tested on OSXElCapitan/Ubuntu16.10/Windows10

0.1.2

• Empty priv is committed and included in hex package so that native libraries get copied to _build when compiled as dependency

0.1.1

• Tests pass on a clean Windows 10 VM (see build.bat)
• Automatic test against Ubuntu 16 & Windows 10

0.1.0

• Drop mac target until stable serial ports
• Ubuntu 16.04 64 and Windows 10 Pro 64 support
• Extract baud nif branch to its own repo

Research

• Bypass the 0.1s minimum granularity on posix systems
• Higher baud rates support for posix and win32
• DTR/RTS control and CTS/DSR monitoring
• Unit test 8N1 7E1 7O1 and baud rate setup against a confirmed gauge
• Posix async and Windows overlapped
• _CRT_SECURE_NO_WARNINGS and strncpy_s suggestion in Windows
• Buffer discarding

References

• https://www.cmrr.umn.edu/~strupp/serial.html