{"id":659,"date":"2010-11-08T12:33:52","date_gmt":"2010-11-08T17:33:52","guid":{"rendered":"http:\/\/embedded-lab.com\/blog\/?p=659"},"modified":"2012-07-30T09:29:31","modified_gmt":"2012-07-30T13:29:31","slug":"lab-3-a-4-bit-binary-counter","status":"publish","type":"post","link":"https:\/\/embedded-lab.com\/blog\/lab-3-a-4-bit-binary-counter\/","title":{"rendered":"Lab 3: Four bit binary counter"},"content":{"rendered":"

Description<\/strong><\/p>\n

Today’s lab session is about binary counting LEDs. The binary 1 and 0 will be represented by turning LEDs on and off. You will make a 4-bit binary counter (using 4 LEDs) that counts from 0 to 15 (0000-1111 binary). The four LEDs are connected to RC0 through RC3 port pins of PIC16F688 with current limiting resistors (470? each) in series. A push button switch is connected to pin RC4 to provide input for the counter. The counter starts from 0, and increase by 1 every time the button is pressed. When the counter reaches 15 (all LEDs on), it will reset to 0 on the next press of the button.<\/p>\n

Required Theory<\/strong><\/p>\n

You should be familiar with the digital I\/O ports of PIC16F688 and their direction settings. If you are not, read Digital I\/O Ports in PIC16F688<\/strong><\/a>. <\/em>Read previous lab session (Lab 2: Basic digital input and output<\/em><\/strong><\/a>) to learn about reading inputs from a push button.
\n
\nCircuit Diagram<\/strong><\/p>\n

The circuit diagram and its construction on the breadboard are shown in figures below. The PIC16F688 microcontroller uses its internal clock at 4.0 MHz.<\/p>\n

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Software<\/strong><\/p>\n

Define PORTC pins RC0-RC3 as output, and the pin RC4 as an input. Disable comparators (CMCON0=7), and configure all I\/O pins as digital (ANSEL=0). Use Button() function to read input from the push button switch.<\/p>\n

\/*<\/span><\/pre>\n
 Lab 3: 4-bit up counter<\/span><\/pre>\n
 Internal Clock @ 4MHz, MCLR Enabled, PWRT Enabled, WDT OFF<\/span><\/pre>\n
 Copyright @ Rajendra Bhatt<\/span><\/pre>\n
 Nov 6, 2010<\/span><\/pre>\n
*\/<\/span><\/pre>\n
\/\/ Define Tact switch @ RC4<\/span><\/pre>\n
 sbit Switch at RC4_bit;<\/span><\/pre>\n
\/\/ Define button Switch parameters<\/span><\/pre>\n
 #define Switch_Pin 4<\/span><\/pre>\n
 #define Switch_Port PORTC<\/span><\/pre>\n
 #define Debounce_Time 20 \u00a0\/\/ Switch Debounce time 20ms<\/span><\/pre>\n
 unsigned short count;<\/span><\/pre>\n
 void main() {<\/span><\/pre>\n
 ANSEL = 0b00000000; \/\/All I\/O pins are configured as digital<\/span><\/pre>\n
 CMCON0 = 0x07 ; \/\/ Disbale comparators<\/span><\/pre>\n
 TRISC = 0b00010000; \/\/ PORTC all output except RC4<\/span><\/pre>\n
 TRISA = 0b00001000; \/\/ PORTA All Outputs, Except RA3<\/span><\/pre>\n
 count = 0;<\/span><\/pre>\n
 PORTC = count;<\/span><\/pre>\n
 do {<\/span><\/pre>\n
 if (Button(&Switch_Port, Switch_Pin, Debounce_Time, 0)) {<\/span><\/pre>\n
 if (!Switch) {<\/span><\/pre>\n
 count ++;<\/span><\/pre>\n
 if (count ==16) count =0;<\/span><\/pre>\n
 PORTC = count;<\/span><\/pre>\n
 }<\/span><\/pre>\n
 while (!Switch); \/\/ Wait till the button is \u00a0released<\/span><\/pre>\n
 }<\/span><\/pre>\n
 } while(1); \u00a0\/\/ Infinite Loop<\/span><\/pre>\n
}<\/span><\/pre>\n
Download HEX file<\/a><\/p>\n
Output<\/strong><\/p>\n
The counter starts from 0 (all LEDs off), and is incremented by 1 on every button press. After it reaches 15, it overflows and takes the next value 0. This repeats forever.<\/p>\n
\"\"<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"
Description Today’s lab session is about binary counting LEDs. The binary 1 and 0 will be represented by turning LEDs on and off. You will make a 4-bit binary counter (using 4 LEDs) that counts from 0 to 15 (0000-1111 binary). The four LEDs are connected to RC0 through RC3 port pins of PIC16F688 with current limiting resistors (470? each) in series. A push button switch is connected to pin RC4 to provide input for the counter. The counter starts from 0, and increase by 1 every time the button is pressed. When the counter reaches 15 (all LEDs on),<\/p>\n","protected":false},"author":2,"featured_media":720,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[32,4,38],"tags":[80,81,20],"class_list":["post-659","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-embedded-labs","category-pic-projects","category-pic-tutorials","tag-binary-counter","tag-pic-lesson","tag-pic16f688"],"_links":{"self":[{"href":"https:\/\/embedded-lab.com\/blog\/wp-json\/wp\/v2\/posts\/659","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/embedded-lab.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/embedded-lab.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/embedded-lab.com\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/embedded-lab.com\/blog\/wp-json\/wp\/v2\/comments?post=659"}],"version-history":[{"count":18,"href":"https:\/\/embedded-lab.com\/blog\/wp-json\/wp\/v2\/posts\/659\/revisions"}],"predecessor-version":[{"id":759,"href":"https:\/\/embedded-lab.com\/blog\/wp-json\/wp\/v2\/posts\/659\/revisions\/759"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/embedded-lab.com\/blog\/wp-json\/wp\/v2\/media\/720"}],"wp:attachment":[{"href":"https:\/\/embedded-lab.com\/blog\/wp-json\/wp\/v2\/media?parent=659"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/embedded-lab.com\/blog\/wp-json\/wp\/v2\/categories?post=659"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/embedded-lab.com\/blog\/wp-json\/wp\/v2\/tags?post=659"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}