User manual
Table Of Contents
- Chapter 1. Overview
- 1.1 Introduction
- 1.2 Highlights
- 1.3 PICDEM™ Lab Development Kit Contents
- 1.4 PICDEM™ Lab Development Board Construction and Layout
- 1.5 Target Power
- 1.6 Connecting the PICkit™ 2 Programmer/Debugger
- 1.7 Solderless Prototyping Area Strip Configuration
- Chapter 2. Getting Started
- 2.1 Introduction
- 2.2 Prerequisites
- 2.3 The Software Control Loop
- 2.4 MPLAB® IDE Download Instructions
- 2.5 Installing the Included Lab Files
- Chapter 3. General Purpose Input/Output Labs
- 3.1 Introduction
- 3.2 General Purpose Input/Output Labs
- 3.3 GPIO Output Labs
- 3.3.1 Reference Documentation
- 3.3.2 Equipment Required for GPIO Output Labs
- 3.3.3 PICDEM Lab Development Board Setup for GPIO Output Labs
- Figure 3-1: PICDEM Lab Schematic for GPIO Output Labs
- 3.3.4 Lab 1: Light LEDs
- Figure 3-2: MAIN() Software Control Loop Flowchart for Lab 1
- Figure 3-3: Step One
- Figure 3-4: Step Two
- Figure 3-5: Step Three
- Figure 3-6: Step Four
- Figure 3-7: Summary
- Figure 3-8: Project Window
- Figure 3-9: PICkit 2 PROGRAMMER/DEBUGGER TOOLBAR
- Figure 3-10: Lab 1 LED Output
- 3.3.5 Lab 2: Flash LEDs (Delay Loop)
- Figure 3-11: Main() Software Control Loop Flowchart for Lab 2
- Figure 3-12: Timing() Delay Routine Flowchart for Lab 2
- 3.3.6 Lab 3: Simple Delays Using Timer0
- Equation 3-1: TMR0 Overflow Period using FOSC/4
- Equation 3-2: TMR0 Overflow Period when including the Prescaler
- Equation 3-3: Calculating a TMR0 PreLoad Value to generate a 10mS Overflow Period
- Figure 3-13: Delay_10mS() using Timer0
- Equation 3-4: Maximum TMR0 Overflow Period
- Figure 3-14: Delay_1S() using Timer0
- 3.3.7 Lab 4: Rotate LEDs
- Figure 3-15: Main() Software Control Loop Flowchart for Lab 4
- Figure 3-16: Decide() Flowchart for Lab 4
- Figure 3-17: Results of Do_Output()
- 3.4 GPIO Input Labs
- 3.4.1 Reference Documentation
- 3.4.2 Equipment Required for GPIO Input Labs
- 3.4.3 PICDEM Lab Development Board Setup for GPIO Input Labs
- Figure 3-18: PICDEM Lab Schematic for GPIO Input Labs
- 3.4.4 Lab 5: Adding a Push Button
- Figure 3-19: Main() Software Control Loop Flowchart for Lab 5
- Figure 3-20: Get_Inputs() Software Flowchart for Lab 5
- Figure 3-21: Delay_5mS() Software Flowchart for Lab 5
- Figure 3-22: Decide() Software FlowChart for Lab 5
- 3.4.5 Lab 6: Push Button Interrupt
- Figure 3-23: Main() Software Control Loop Flowchart for GPIO Lab 6
- Figure 3-24: pb_pressISR() for Lab 6 Showing Switch Debounce
- 3.4.6 Lab 7: Push Button Interrupt-on-Change
- Figure 3-25: pb_pressisr Flowchart for Lab 7
- 3.4.7 Lab 8: Using Weak Pull-Ups
- Chapter 4. Comparator Peripheral Labs
- 4.1 Introduction
- 4.2 Comparator Labs
- 4.2.1 Reference Documentation
- 4.2.2 Comparator Labs
- 4.2.3 Equipment Required
- 4.2.4 Lab 1: Simple Compare
- Figure 4-1: Schematic for Comparator Lab 1
- Figure 4-2: Main() software Control Loop Flowchart for Comparator Lab 1
- 4.2.5 Lab 2: Using the Comparator Voltage Reference
- Equation 4-1: CVref Output Voltage
- Equation 4-2: Calculating a 2.5V Internal Reference (Low-Range Method)
- Figure 4-3: Schematic for Comparator Lab 2
- 4.2.6 Lab 3: Higher Resolution Sensor Readings Using a Single Comparator
- Figure 4-4: Basic Relaxation Oscillator Circuit
- Figure 4-5: Schematic for Comparator Lab 3
- Figure 4-6: Main() software Control Loop Flowchart for Comparator Lab 3
- Figure 4-7: TMR0_ISR Flowchart for Comparator Lab 3
- Chapter 5. Analog-to-Digital Converter Peripheral Labs
- 5.1 Introduction
- 5.2 ADC Labs
- Figure 5-1: Schematic for ADC Lab 1
- Figure 5-2: Main() software Control Loop Flowchart for Comparator Lab 1
- Figure 5-3: Main() software Control Loop Flowchart for Comparator Lab 1
- Figure 5-4: ADC Result Bit Significance
- Figure 5-5: Schematic for ADC Lab 2
- Figure 5-6: Main() software Control Loop Flowchart for ADC Lab 2
- Appendix A. Schematic
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Lab Development Board User’s Guide
DS41369A-page 52 © 2009 Microchip Technology Inc.
EXAMPLE 3-24: INITIALIZE() CODE FOR GPIO LAB 6
It should be noted that the Global Interrupt Enable bit (GIE) is set last in the
Example 3-24. This ensures that interrupts will not occur during the Initialize(),
having adverse consequences on code operation.
//Clear PORTC to a known state
//Set the least significant bit to 1 so that it can be
//shifted through
PORTC = 0b00000001;
//Clear the PORTA register to a known state
PORTA = 0b00000000;
//Configure PORTC's ANALOG/DIGITAL pins as all Digital
ANS4 = 0;//Associated with RC0
ANS5 = 0;//Associated with RC1
ANS6 = 0;//Associated with RC2
ANS7 = 0;//Associated with RC3
ANS8 = 0;//Associated with RC6
ANS9 = 0;//Associated with RC7
//Configure PORTC pins as all output
//i.e. 1 = Input, 0 = Output
TRISC0 = 0;//Associated with RC0
TRISC1 = 0;//Associated with RC1
TRISC2 = 0;//Associated with RC2
TRISC3 = 0;//Associated with RC3
TRISC4 = 0;//Associated with RC4
TRISC5 = 0;//Associated with RC5
TRISC6 = 0;//Associated with RC6
TRISC7 = 0;//Associated with RC7
//Configure PORTA bit RA0 as Digital input
ANS2 = 0;
TRISA2 = 1;
//Configure Timer0 to overflow every 5mS
T0CS = 0; //Select FOSC/4 as Timer0 clock source
T0SE = 0; //Increment TMR0 on rising clock edge
PSA = 0; //Assign prescaler to Timer0
//Select a 1:32 prescaler
PS0 = 0;
PS1 = 0;
PS2 = 1;
//Initialize the direction flag to shift bits from
//right-to-left
//(i.e. 0 = Shift PORTC bits from right-to-left
// 1 = Shift PORTC bits from left-to-right
direction = 0;
//Initialize LED_Output to all zeros
LED_Output = 0b00000000;
//Configure for external interrupts on RA2
INTEDG = 0; //Interrupt to occur on High-to-LOW
//transition of RA2 voltage
INTE = 1; //Enable the external interrupt
INTF = 0; //Clear the external interrupt flag
GIE = 1;//Enable interrupt capability on the
//PIC16F690 ***ALWAYS DONE LAST*****