This program shows how to use ULN2003A and PWM mode to control light dimming. When program run, the DC light will dim from dark to bright. This tutorial will work with the Hi-Tech C compilers. 

PWM (Pulse-width modulation) Operations:

• PWM Period = [(PR2) + 1] x 4 x Tosc x (TMR2 Prescale Value)
• Pulse Width = (CCPRxL:CCPxCON) x Tosc x (TMR2 Prescale Value)
• Duty Cycle Ratio = (CCPRxL:CCPxCON)/4(PR2 + 1)
• Tosc = 1 / Fosc

iBoard connection:

• RC2(CCP1): ULN2003A Module (O3): LED Light (-)
• * (12Vdc): ULN2003A Module (*): LED Light (+)

  Video:

• Tutorial 9 - Light Dimming Demo: Video

Download:

• Tutorial 9 - Light Dimming Demo: Source Code; Schematic
• ULN2003A Datasheet: Link
• PIC16F722 DataSheet
• MPLAB IDE 8.40 (93.7MB)
• Hi-Tech C Setup Guide
• Hi-Tech C User Guide