Advanced PIC24 C Programming
Duration: 5 Days
The C programming language is over 40 years old. It is a testament to the genius of the gifted researchers at Bell Labs who developed it that it is still very widely used. C programming is a mainstay of embedded systems programming. In an age where traditional analog systems have. laregely, been replaced by digital systems capable of capturing and processing analog inputs digitally and controlling analog outputs digitally knowing how to program in C is an essential skill. The genius of C is that it is both a high level programming language, and yet, one that is very close to assembler. The aim of an advanced C programming course is to provide an overview of more advanced C programming techniques. These include coverage of dynamic data structures and algorithms such as linked lists and binary trees, the implementation and use of circular buffers and simple memory management systems as well as the use of state machine based approaches to areas such as protocol implementation and multi-tasking.
Course Prerequisites and Target Audience
A sound basic knowledge of C, preferably in the context of embedded systems application development is assumed, to the level covered in the Introduction to PIC24 C programming course.
The course emphasises the implementation of disciplined and well structured code and the design of modules with clean interfaces. Topics include:
- Advanced use of dynamic data structures and algorithms for manipulating them.
- Structured interrupt handling
- Implementation of simple schedulers and operating systems
- Working with embedded operating systems
- Understanding standard techniques for inter-process communication, and their uses.
- Finite state machines, statecharts, and their uses
- Advanced algorithms and research-oriented approaches
Lab exercises are used to consolidate key concepts.
The course uses PIC24 and dsPIC systems as a platform for hands-on work. The course also covers basic multi-tasking techniques using state machine driven scheduling approaches and simple timer interrupt driven deterministic scheduling techniques. The course uses the MPLABX IDE and the Microchip XC16 compiler. A variant of this course using the older MPLAB IDE and the C30 compiler is available on request.
Students successfully completing this course will have a sound understanding of C programming. You will understand the basic C data types, arrays and pointers.
You will have a good appreciation of data structures and their uses, and the use of pointers to data structures and arrays of data structures.
You'll learn how to use arrays to implement circular buffers and how to use them, and how to use arrays to implement stacks, and the uses of software stacks.
You will also be introduced to basic techniques of memory management and programming with dynamic data structures - and to circular buffers and stacks and linked lists. You'll also learn techniques for implementing interrupt handler code in C, multi-module programming including applications containing a mixture of C and assembly language modules, and techniques for manipulating hardware registers and special function registers in C.
Students completing this course will considerably improve the discipline and rigour with which they design and write embedded systems applications in C.
You'll be able to implement classical data structures such as circular buffers, linked lists, and trees -- and you'll know when it's appropriate to use them.
You'll be exposed to a variety of advanced programming idioms and algorithms with their associated data structures, for tasks such as indexing, data compression and error detection.
You'll learn to write event driven programs, to implement Finite State Machines, and to design hierarchical state machines using statecharts.
You'll learn structured programming techniques for implementing multi-tasking applications.
You will also learn basic techniques for mixed C and Assembler programming
The hands on exercises also introduce the use of simulation, debugging and In Circuit Debugging techniques, as well as techniques for In System Programming.
The knowledge acquired on this course can be readily transferred to other processor architectures such as PIC24, dsPIC and PIC32.
- Intensive overview of essential C concepts and idioms
- Data types, data structures, pointers and arrays
- Using pointers to search collections of data
- Arrays and buffers
- Circular buffers
- Polygonal buffers
- I/O vectors
- Linked Lists in depth
- Singly linked and doubly linked lists
- Using lists to implements FIFO queues and LIFO queues (stacks)
- Using lists of linked lists
- Using linked list nodes containing void * pointers to implement heterogeneous collections of data
- Using linked lists to implement resizeable arrays
- Binary trees, their uses and their relations
- Basic binary trees
- Self-balancing binary trees (AVL, Red-Black, Splay)
- Heaps and their uses
- Huffman encoding
- Priority queues
- Error detection
- CRC checksums (16 bit and 32 bit)
- Implementing simple memory management schemes
- Implementing simple flash memory file systems
- State Machines and Statecharts
- Event driven programming
- Basic FSMs
- Pattern matching
- State driven hardware and communication protocols
- Implementing FSMs using switch statements
- Implementing FSMs using a table driven approach
- Limitations of FSMs
- Extended FSMs and hierarchical FSMs
- Extending FSMs by adding variables and conditional transitions
- Nesting state machines (push down automata)
- Hierachical FSMs and extended FSMs (simple statecharts)
- Orthogonal statecharts and concurrency
- Active objects - linking multi-tasking, message passing and event driven programming
- Basic Multi Tasking
- Multi tasking concepts
- What is meant by Real Time ?
- Soft vs. Hard Real Time
- What is a scheduler?
- Scheduling without an operating system
- State machines and mosaic schedulers
- Timer interrupt and task queue based scheduling
- Polling vs. Interrupts for working with peripherals ?
- Synchronisation mechanisms in operating systems free applications
- Optional - Advanced Module - FreeRTOS on the PIC24
- Task structures
- Task life cycle
- Task management
- Task data structures
- Task queues
- Message queues
- Semaphores (counting, binary, mutex)
- Memory management services
- Device drivers
- Optional - Advanced Module - FreeRTOS Standard Inter-Process Communication Idioms
- Producer - Consumer
- Readers and Writers