PIC course

1. 1 PIC course Program design - Assignment hand-out Microchip – PICs and MPLAB 3) Input and Output – Digital and serial I/O 4) Debugging – using MPLAB simulator 5) Lab session 6) Analogue input 7) Interrupt programming – external and timers 8) Simulator - stimulus and DCMI 9) Test 2 – Assignment hand-in

2. 2 PIC course – PICs and MPLAB Programmable Interface Controllers (PICs) Why PICs ? Cheap, programmable devices Large variety I/O options. - Plus advanced I/O - USB, Ethernet, Manufactured by Microchip, www.microchip.com

3. 3 PIC course – PICs and MPLAB A few flavours: Low-end devices: (12-bit instruction size) – e.g. PIC16C5X Mid-range devices (14-bit instruction size) High(er)-end devices: (16-bit instruction size) – PIC18 range – we’ll use the PIC18C452 Top-end devices: (16-bit instruction and data word) – PIC24

4. 4 PIC course – PICs and MPLAB 18C452 Features: Operating voltage Standard: 4.5 - 5.5V, L parts: 2 – 6V Frequency DC – 40MHz Oscillator Crystal, external RC Program memory (bytes) 32K Data Memory (Bytes) 1536 I/O Ports 5 – Ports A, B, C, D, E Timers 4 Capture/Compare/PWM 2 Serial Communications MSSP, USART Parallel Communications PSP 10-bit Analog-to-Digital Module 8 input channels Programming In-circuit serial, or programmer

5. 5 PIC course – PICs and MPLAB Pin-out – note multi-function pins

6. 6 PIC course – PICs and MPLAB Circuit – simple – Clock: RC or crystal

7. 7 PIC course – PICs and MPLAB PIC registers PIC is controlled by Special Function Registers (SFR) I/O ports: TRIS (tri-state control register) – TRISA for PORTA, TRISB for PORTB etc. A ‘0’ sets pin as output - a ‘1’ sets it as input. Other SFRs, e.g: Analogue, timer, control and capture register Programming: SFRs defined in .H header file.

8. 8 PIC course – PICs and MPLAB PIC configuration register Holds design set-up e.g oscillator type (RC, crystal) and speed, watch dog timer, brown out & low voltage detect levels etc. Is controlled by a fuse, set when PIC programmed If relevant, have to set in code – e.g: #pragma config WDT = OFF

9. 9 PIC course – PICs and MPLAB C Programming ANSI – slightly different from C# (no Console reads or write) - No Op Sys or pre-written I/O with embedded systems Microchip MCC18 compiler MPLAB program debugger environment Free from Microchip – see notes

10. 10 PIC course – PICs and MPLAB Program is compiled, linked (with other programs) and run under MPLAB. MPLAB does have serial output emulator This week’s task First program writes to this.

11. 11 PIC course – PICs and MPLAB First program: // // Hello.c - prints Hello world ! - jba 6/09 // #include <stdio.h> // includes the printf definition #pragma config WDT = OFF // command to C18 - turn off the watch-dog timer - later void main (void) // main program starts here { printf ("Hello World !"); // print to MPLAB output window while (1) ; // permanent loop to end prog. }

12. 12 PIC course – PICs and MPLAB Other embedded processors ARM processors The ARM (Advanced RISC Machine) 32-bit architecture Used in PDAs, iPODs and mobile phones. There are many variants but they all use the same processor core. C compilers are available for these.

13. 13 PIC course – PICs and MPLAB Other embedded processors Arduino board Uses Atmel ATMega 32 bit processor Programmed via USB port Expanded using plug-in modules

14. 14 PIC course – PICs and MPLAB Summary PIC devices Features Pin-out Hardware design SFRs MCC18 & MPLAB First program Other embedded processors

15. 15 PIC course – PICs and MPLAB This week’s task Type in ‘Hello World’ program Run MPLAB – set up environment (PIC, add C program and link to PIC library and header files, set Memory model) Set output window to simulate serial I/O Run program Output: