SCPI parser

This library provides a simple ("KISS") SCPI implementation for embedded devices (instruments).

The implementation is not 100% complete, but it's sufficient for basic SCPI communication.

What's supported

• The hierarchical header model (commands with colon)
• Long and short header variants (eg. SYSTem?)
• Easy configuration with one const array of structs and callback functions (see main.c)
• Semicolon for chaining commands on the same level
• String, Int, Float, Bool arguments
• Block data argument with callback each N received bytes (configurable)
• Status Register model
• Error queue including error messages from the SCPI spec
• All mandatory SCPI commands (headers) are implemented as built-ins

Built-in commands can be overriden in user command array.

See main.c for example of how to use the library.

What is missing

• Setting error type flags in the ESR when error is added to queue
• There may be some bugs in the status registers (not tested much)
• Character data argument ("string without quotes", enum-like)
• Number units and metric suffixes (k,M,G,m,u,n)
• DEF, MIN, MAX, INF, NINF argument values for numbers

Support for units and "constants" (DEF etc) in numeric fields will need some larger changes to the numeric parser and SCPI_argval_t.

Feel free to propose a pull request implementing any missing features.