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PIC Development Environment
MPLAB IDE integrates all of the tools that we
will use

• Project Manager -Groups together all files and
  data related to a project
• Editor Standard text editor to write code with
• Assembler and Linker Stand-alone or to group
  several sources/libraries
• Debugger Standard debugger, used with simulator
  or in-circuit emulator
• Execution Engines Instruction-level simulators
  for PIC devices
• Programmer Transfers the executable to the PIC
  part

Cross-Compiler generates PIC machine code from a
high-level language We need a C cross-compiler,
will use HI-TECH C for PIC10/12/16
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Downloading/Installing Tools

• PICKit 1 comes with CDs but you should download
  the newest versions
• MPLAB IDE
• Go to www.microchip.com, select MPLAB IDE link
• Select MPLAB IDE v8.50 Full Release Zipped
  Installation link
• Unzip and install
• During the installation you will be prompted to
  download/install Hi-Tech C Compiler

• HI-TECH C Compiler
• You may need to install this directly
• Go to www.htsoft.com
• Select PIC10/12/16 MCUs
• Download lite mode v9.70
• Include PICC path in your path when prompted

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Development Example
How to Make a Project 1. Write some C code using
an editor, save it in a directory Try
blinking-LED code on course webpage 2. Create a
new project using Project gt Project Wizard 3.
Select device PIC16F684 4. Prompt Select a
language toolsuite, choose HI-TECH Universal
Toolsuite 4. Choose a name and directory for your
project 5. Prompt Add Existing Files, add your C
source file Select the C source file on the
left, click Add button 6. Select Finish if
everything looks OK
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Compiling and Programming

• 1. Select Project gt Build to compile the project
• - You should see a window and eventually a
  Build Successful msg
• 2. Plug in the PICKit 1
• 3. Choose board with Select Programmer gt PICKit 1
• 4. Program the PIC with Programmer gt Program
  Device
• The program should run after a few seconds.

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Simulation with MPLAB

• Simulation is useful to try before hooking up
  real hardware
• Simulation is not perfectly accurate
• No understanding of analog effects

• Debugger gt Select Tool gt MPLAB Sim to start
  simulator
• Basic Debugger Operations (via new buttons)
• Run
• Pause
• Animate run slowly
• Step In step to next line
• Step Over step past a function
• Step Out complete current function
• Reset start simulation at beginning

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Breakpoints, Timing, Watching

• Breakpoints
• Set breakpoints by double-clicking on the line of
  code
• Manage breakpoints using Debugger gt Breakpoints
• Stopwatch
• Debugger gt Stopwatch shows cycle count and time
• Useful to make delays with loops
• Watch Window
• Watch window shows register and variable contents
• Add SFR to add a register, Add Symbol to add a
  variable

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Blinking LED Code
include ltpic.hgt __CONFIG (FCMDIS IESODIS
BORDIS UNPROTECT MCLRDIS PWRTEN WDTDIS
INTIO) main () int i PORTA 0 TRISA4
0 TRISA5 0 while (1 1) for(i0 i lt
25000 i) RA4 RA4 gt 1
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Blinking Light Code Components

• Include required libraries
• includeltpic.hgt defines the memory mapping of all
  special registers
• Set the Configuration Bits of the microcontroller
• These bits control processor functions (clock
  source, watchdog, etc.
• Use __CONFIG macro to set them in C
• Be careful with these
• Initialize I/O pins input or output? Initialize
  values
• Infinite while loop Common in embedded systems
• Delay loop Needed to slow system to match human
  perception

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Controlling Digital I/O Pins

• PORTA is a 6 bit bi-directional port
• TRISA is the corresponding direction register
• Setting a TRISA pin 1 makes the corresponding
  PORTA pin an input
• Clearing a TRISA pin makes the corresponding
  PORTA pin an output
• Reading the PORTA register shows the status of
  the pins
• Writing to PORTA writes to the pins (if they are
  outputs)
• Can refer to individual bits in the PORTA and
  TRISA registers
• TRISA0 0
• RA0 1

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Length of Delay Loop
for (i0 ilt25000 i)
Clock freq 4MHz, Period 250 ns

• How long is this loop?
• 25000 clocks?
• Loop needs to compare i to 25000 and to increment
  i.
• 25000 is larger than 8 bits.

• Need to see the assembly code to know for sure.