Generating PWM with PIC18F4520 Revision as of 15:11, 10 August 2016 by Sharana (Talk | contribs) (diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)

In this tutorial we will see how to generate the PWM signals using PIC18F4520.

Prerequisites

Please check this tutorial for detailed explanation on PIC18F4520 PWM module.

PIC18F4520 PWM Module

PIC18F4520 microcontroller has two independent CCP(Capture/Compare/PWM) modules, named as CCP1 and CCP2. Each CCP module has two 8-bit resistors(CCPxH,CCPxL) that can be use as:

• 16 bit Capture Register
• 16 bit Compare Register
• 10-bit PWM Register.

In this tutorial we will be discussing only the PWM part of CCP. PIC has 2PWM module with a resolution of 10-bits.
Below tables shows the PWM module of PIC.

PWM Channel	Port Pin	Control Register	Duty Cycle Register	Period Register
PWM1	PC.2	CCP1CON	CCPR1L	PR2
PWM2	PC.1	CCP2CON	CCPR2L	PR2

Code1

Below is the example to vary the brightness of the LED(PC.2) using PWM.

Code2

Progarm to generate the PWM signals of 25% & 75% duty cycle.

Ouptut measured using CRO: