Summary of PIC16F877 timer1 code and Proteus simulation
This tutorial explains using Timer1 and its interrupts on the PIC16F877, with example C code (HI-TECH C) and a Proteus simulation. It shows a 20 MHz crystal setup where Timer1 triggers an ISR that toggles RB0 about every 13 ms; the period can be changed in code. The article assumes basic PIC LED blinking knowledge and provides downloadable code and Proteus files.
Parts used in the PIC16F877 Timer1 tutorial:
- PIC16F877 microcontroller
- 20 MHz external crystal
- Proteus simulation software (for verifying circuit and code)
- MPLAB IDE (version used: v8.85)
- HI-TECH C compiler (version used: v9.83)
- LED (implied for observing RB0 toggling)
- Downloadable project files (code and Proteus simulation)
This PIC16F877 microcontroller tutorial answers the question,
” How to use timer1 of PIC16F877 and how to handle its interrupts? ”
Using PIC16 simulator (Proteus) you can verify this PIC timer1 code and change it according to your needs. This code is written in C language using MPLAB with HI-TECH C compiler. You can download this code from the ‘Downloads‘ section at the bottom of this page.
It is assumed that you know how to blink an LED with PIC16F877 microcontroller. If you don’t then please read this page first, before proceeding with this article.
The following diagram (made in Proteus) shows the PIC microcontroller circuit diagram.
In this circuit, PIC16F877 is running on external crystal of 20MHz value. RB0 pin is toggled every time timer1 expires and executes it’s ISR[1] code. In the above figure, it is clear that after approximately every 13msec, RB0 pin is toggled i-e timer1 expires. You can easily change this value in the code.
Code
The main function code is shown below.
Downloads
Timer1 code for PIC16F877 was compiled in MPLAB v8.85 with HI-TECH C v9.83 compiler and simulation was made in Proteus v7.10. To download code and Proteus simulation click here.
For more detail: PIC16F877 timer1 code and Proteus simulation
- How is Timer1 of PIC16F877 demonstrated in the tutorial?
Timer1 is configured to generate interrupts; its ISR toggles RB0 approximately every 13 ms as shown in the Proteus circuit and example C code. - Can I simulate the Timer1 example before using hardware?
Yes, the tutorial uses Proteus to verify the PIC Timer1 code and simulation files are provided for download. - What compiler and IDE were used to build the Timer1 code?
The code was compiled using HI-TECH C v9.83 in MPLAB v8.85. - Does the tutorial require prior PIC knowledge?
Yes, it assumes you know how to blink an LED with PIC16F877; it recommends reading a referenced page if you do not. - How often does the example toggle RB0 when Timer1 expires?
The example toggles RB0 approximately every 13 ms, and this value can be changed in the code. - What clock source is used in the example circuit?
The PIC16F877 in the example runs on an external 20 MHz crystal. - Where can I get the example code and Proteus files?
The article provides downloadable code and Proteus simulation files via the Downloads section and a link to download them.
