README.md

# baud

Elixir Serial Port with Modbus RTU.

## Installation and Usage

  1. Add `baud` to your list of dependencies in `mix.exs`:

  ```elixir
  def deps do
    [{:baud, "~> 0.5.6"}]
  end
  ```

  2. Enumerate your serial ports.

  ```elixir
  ["COM1", "ttyUSB0", "cu.usbserial-FTVFV143"] = Baud.Enum.list()
  ```

  3. Interact with your serial port.

  ```elixir
  tty = case :os.type() do
    {:unix, :darwin} -> "cu.usbserial-FTYHQD9MA"
    {:unix, :linux} -> "ttyUSB0"
    {:win32, :nt} -> "COM5"
  end

  # try this with a loopback
  {:ok, pid} = Baud.start_link(device: tty)

  Baud.write pid, "01234\n56789\n98765\n43210"
  {:ok, "01234\n"} = Baud.readln pid
  {:ok, "56789\n"} = Baud.readln pid
  {:ok, "98765\n"} = Baud.readln pid
  {:to, "43210"} = Baud.readln pid

  Baud.write pid, "01234\r56789\r98765\r43210"
  {:ok, "01234\r"} = Baud.readch pid, 0x0d
  {:ok, "56789\r"} = Baud.readch pid, 0x0d
  {:ok, "98765\r"} = Baud.readch pid, 0x0d
  {:to, "43210"} = Baud.readch pid, 0x0d

  Baud.write pid, "01234\n56789\n98765\n43210"
  {:ok, "01234\n"} = Baud.readn pid, 6
  {:ok, "56789\n"} = Baud.readn pid, 6
  {:ok, "98765\n"} = Baud.readn pid, 6
  {:to, "43210"} = Baud.readn pid, 6

  Baud.write pid, "01234\n"
  Baud.write pid, "56789\n"
  Baud.write pid, "98765\n"
  Baud.write pid, "43210"
  :timer.sleep 100
  {:ok, "01234\n56789\n98765\n43210"} = Baud.readall pid
  ```

  4. Interact with your **RTU** devices.

  ```elixir    
  alias Modbus.Rtu.Master

  tty = case :os.type() do
    {:unix, :darwin} -> "cu.usbserial-FTVFV143"
    {:unix, :linux} -> "ttyUSB0"
    {:win32, :nt} -> "COM5"
  end

  # rs485 usb adapter to modport
  {:ok, pid} = Master.start_link(device: tty, speed: 57600)
  # force 0 to coil at slave 1 address 3000
  :ok = Master.exec pid, {:fc, 1, 3000, 0}
  # read 0 from coil at slave 1 address 3000
  {:ok, [0]} = Master.exec pid, {:rc, 1, 3000, 1}
  # force 10 to coils at slave 1 address 3000 to 3001
  :ok = Master.exec pid, {:fc, 1, 3000, [1, 0]}
  # read 10 from coils at slave 1 address 3000 to 3001
  {:ok, [1, 0]} = Master.exec pid, {:rc, 1, 3000, 2}
  # preset 55AA to holding register at slave 1 address 3300
  :ok = Master.exec pid, {:phr, 1, 3300, 0x55AA}
  # read 55AA from holding register at slave 1 address 3300 to 3301
  {:ok, [0x55AA]} = Master.exec pid, {:rhr, 1, 3300, 1}
  ```

## Development

  - Testing requires two null modem serial ports configured in `test/test_helper.exs`

## Windows

Install `Visual C++ 2015 Build Tools` by one of the following methods:
  - Download and install [visualcppbuildtools_full.exe](http://landinghub.visualstudio.com/visual-cpp-build-tools)
  - Thru [Chocolatey](https://chocolatey.org/) `choco install VisualCppBuildTools`.

From the Windows run command launch `cmd /K c:\Users\samuel\Documents\github\baud\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.

## Roadmap

Future

- [ ] Remote compile mix task to Linux & Windows
- [ ] Pass test serial port thru environment variables

0.5.4

- [x] Updated to sniff 0.1.4

0.5.3

- [x] Updated to sniff 0.1.3
- [x] Document Windows/Ubuntu dependencies

0.5.2

- [x] Updated to sniff 0.1.2 need for ´iex -S mix´ to find native library in Elixir 1.5.1
- [x] Updated to modbus 0.3.7

0.5.1

- [x] Updated to sniff 0.1.1
- [x] Extract NIF to its own repo (sniff)

0.5.0

- [x] Posix NIF implementation
- [x] Win32 NIF implementation
- [x] Baud api simplification
- [x] Refactored to NIF for improved speed and test isolation
- [x] Removed sock/loop (will be implemented as part of forward)

0.4.3

- [x] Add wait4ch to handle non standard line/packet terminators

0.4.2

- [x] Port proxy added to ensure proper closing on exit status msg
- [x] Kill tests added for both baud and sock
- [x] Refactored from genserver to actor

0.4.1

- [x] Updated Makefile for Windows 10

0.4.0

- [x] Added sample script (1 y 2)
- [x] Improved documentation
- [x] Update to modbus 0.2.0 (refactoring required)

0.3.0

- [x] Integration test script for modport
- [x] Added test.sh to isolate tests run
- [x] RTU master, slave, and tcpgw loop modes
- [x] Serial port export to socket in raw, text, and modbus mode
- [x] RTU API matched to `modbus` package (1,2,3,4,5,6,15,16)
- [x] Improved timeout handling for shorter test times

0.2.0

- [x] Interactive RTU: read/write up to 8 coils at once

0.1.0

- [x] Cross platform native serial port (mac, win, linux)
- [x] Modbus (tcu-rtu), raw and text loop mode

## Research

- [ ] Support udoo neo
- [ ] Support beaglebone black
- [ ] Support raspberry pi 3 B
- [ ] Assess rewriting the windows native code using the win32 api
- [ ] Assess rewriting the windows native code using c#/.net
- [ ] Split into a core package and OS dependant packages holding native code
- [ ] loop* tests still show data corruption when run all at once
- [ ] Implement Modbus ASCII support (no available device)
- [ ] Implement DTR/RTS control and CTS/DSR monitoring
- [ ] Implement separate discard for input and output buffers
- [ ] Unit test 8N1 7E1 7O1 and baud rate setup against a confirmed gauge
- [ ] Get port names required for unit testing from environment variables
- [ ] Implement a clean exit to loop mode for a timely port close and to ensure test isolation
- [ ] Improve debugging: stderr messages are interlaced in mix test output
- [ ] Improve debugging: dev/test/prod conditional output
- [ ] Move from polling to overlapped on Windows
- [ ] Research why interchar timeout is applied when reading a single byte even having many already in the input buffer. Happens on MAC.
- [ ] Research how to bypass the 0.1s minimum granularity on posix systems
- [ ] Research higher baud rates support for posix and win32
- [ ] Research Mix unit test isolation (OS resources cleanup)
- [ ] Research printf to embed variable sized arrays as hex strings