NewMagellan

This repo is primarily a storage area for pre-built binaries of the NewMagellan driver. For now the code will also live in https://github.com/CORE-POS/IS4C. The directory containing NewMallean's code is https://github.com/CORE-POS/IS4C/tree/master/pos/is4c-nf/scale-drivers/drivers/NewMagellan.

The version hosted in this repo has been restructured to behave more sensibly in Visual Studio with a separate project for each output file.

You can absolutely still build your own driver. Just run "msbuild" or "xbuild" in the project directory. The point of these builds is to provide consistency in deployments.

Current builds are 32-bit, .NET 4.0.

Dev Notes

Alphabetically, what are these different projects?

• AxLayer is provides a standardized interface for ActiveX controls that NewMagellan optionally uses. This exists to allow testing without having the actual ActiveX controls present.
• Bitmap deals with signature images. The Signature class can create an image from a list of points. The additional convertor reduces a bitmap to a color depth of 1 (or 1 bit per pixel) which isn't a format natively supported by .NET.
• Discover is a library for converting strings to Type objects. This is used to convert configuration file contents into instances of classes.
• MsgInterface is an interface for classes that can send and receive messages. The main Magellan class, UDPMsgBox, and SerialPortHandlers all implement this interface and use it to exchange messages with one another.
• NewMagellan is the primary project that builds the driver executable.
• ParallelLayer is theoretically a cross-platform wrapper for writing to a parallel port. No real-world testing has occurred with it.
• SPH is the collection of Serial Port Handlers. All of the low-level logic for interacting with devices lives here.
• Tests contains unit tests. This is the only sub-project using F# instead of C#.
• UDBMsgBox is a simple UDP server that can receive messages over the network and relay them to another component.
• USBLayer is essentially a wrapper around HidSharp with alternatives that exist for backward compatibility. With new development using USBWrapper_HidSharp is strongly recommended.

Basic Operation

NewMagellan starts by reading configuration pairs from ../../../config.json (preferred) or ./ports.conf (legacy). A configuration pair consists of a port, such as COM1 or dev/ttyS0 and a serial port handler class, such as SPH_Magellan_Scale. For each pair it creates an instance of the specified class, assigns it to the specified port, and starts that object running in its own thread. Then finally it creates an instance of UDPMsgBox to handle incoming messages. In this arrangement NewMagellan is the parent, or recipient, for both UDPMsgBox and the serial port handlers.

USER <---------------- NewMagellan <----> SPH <-----> Device
    \                  /^
     \__> UDPMsgBox __/

When the user sends a message to the driver:

• UDPMsgBox receives the message. It then sends the message along to NewMagellan.
• NewMagellan relays the message to all serial port handlers
• Each serial port handler can do whatever it wants regarding the message - typically either sending a command to the device or ignoring the message entirely.

When a serial port handler sends a message to the user:

• The serial port handler passes the message to NewMagellan
• NewMagellan transmits the message to the user

Extending

To add support for an additional device, create a new class in the SPH project that inherits from SerialPortHandler (even if the device is not technically serial this is still where the class should go). The class is only required to implement two methods:

• void HandleMsg(string msg) is the method called when NewMagellan needs to pass a message to the serial port handler.
• void Read() is the thread that runs for the life of the application and interacts with the hardware device. Usually this consists of a synchronous or asynchronous loop waiting for input from the device.
• To pass messages back to the user call parent.MsgSend(string msg).