This library is designed to receive serial input on a microprocessor, parse
it, match it against a list of possible commands and call the appropriate
one. It incorporates basic parameter checking (correct number only) and
returns a CommandHandlerReturn object which indicates how each call went.
It is designed to be lightweight in terms of RAM usage: space requirements
are 6 bytes + 8 per command + buffer size, where the buffer should be the
length of your longest possible command (default COMMAND_SIZE_MAX = 128
bytes).
See the example files for a demonstration of how to use the library.
Briefly, to use this library, first create a CommandHander object:
// Create a CommandHandler object to hold 5 commands
CommandHandler<5> h;
Then, create functions that match the template of a commandFunction. In
other words, the must return void and take only a const ParameterLookup&
object as a paremeter. This object contains c strings for each of the
parameters passed to your function by the user.
For example, if the user input VOLT? 1 2.872 hello :
params[0] = "VOLT?"
params[1] = "1"
params[2] = "2.872"
params[3] = "hello"
params[4] = NULL pointer
params[-5] = NULL pointer
Commands must be registered using registerCommand(). E.g. to register the
above command that takes 3 parameters:
h.registerCommand(COMMANDHANDLER_HASH("volt?"), 3, &theFunctionToCall)
N.B. h.registerCommand("volt?", 3, &theFunctionToCall) would also work, but
would store the string in memory which is wasteful.
When serial input is received, you must pass it along to the CommandHandler
using h.addCommandChar.
To check for waiting commands use h.commandWaiting().
To call any queued commands use h.executeCommand().
Since this library is designed to be run on a microcontroller where memory
comes at a premium, it avoid all dynamically assigned memory: all features are
implemented statically and all variables, buffers etc. are assigned on the
stack and have a lifetime tied to the CommandHandler object.