{"id":103,"date":"2009-05-06T23:26:01","date_gmt":"2009-05-06T22:26:01","guid":{"rendered":"http:\/\/stigern.net\/blog\/?p=103"},"modified":"2011-12-16T06:16:22","modified_gmt":"2011-12-16T05:16:22","slug":"how-to-make-a-light-tracker-using-photoresistors","status":"publish","type":"post","link":"https:\/\/stigern.net\/blog\/how-to-make-a-light-tracker-using-photoresistors\/","title":{"rendered":"How to make a light tracker using arduino & photoresistors!"},"content":{"rendered":"

[youtube=http:\/\/www.youtube.com\/watch?v=iEhX27ahreI&w=480&h=385]<\/p>\n

This is how to make a simple light tracker\/follower with the Arduino. The components you need apart from the Arduino is:<\/p>\n

2x Photoresistors<\/a>: “PHOTOCELL2 Miniature Photocell”.
\n2x 470 Ohms resistors<\/a>.
\n1x Servo.<\/a><\/p>\n

And of course some wires<\/a>, and a breadboard <\/a>or two :). Next step is to wire it all up, I’ve made a drawing in Fritzing that you can follow. Basically each photoresistor is wired likes this:<\/p>\n

PhotoR\u00a0\u00a0\u00a0 \u00a0\u00a0 470Ohms
\n+5\u00a0\u00a0\u00a0 o—\/\/\/–.–\/\/\/—o GND
\n|
\nPin 0 & 1 o——-<\/p>\n

\"\"<\/a><\/p>\n

<\/a><\/p>\n

Program Code:<\/p>\n

#include <Servo.h><\/p>\n

Servo myservo;<\/p>\n

int pos = 0;\u00a0 \/\/ Variable to store the servo position.
\nint inputPhotoLeft = 1; \/\/ Easier to read, instead of just 1 or 0.
\nint inputPhotoRight = 0;<\/p>\n

int Left = 0; \/\/ Store readings from the photoresistors.
\nint Right = 0; \/\/ Store readings from the photoresistors.<\/p>\n

void setup()
\n{
\nmyservo.attach(9); \/\/ Attach servo to pin 9.
\n}<\/p>\n

void loop()
\n{
\n\/\/ Reads the values from the photoresistors to the Left and Right variables.
\nLeft = analogRead(inputPhotoLeft);
\nRight = analogRead(inputPhotoRight);<\/p>\n

\/\/ Checks if right is greater than left, if so move to right.
\nif (Left > (Right +20))
\n\/\/ +20 is the deadzone, so it wont jiggle back and forth.
\n{
\nif (pos < 179)
\npos++;
\nmyservo.write(pos);
\n}<\/p>\n

\/\/ Checks if left is greater than right, if so move to left.
\nif (Right > (Left +20))
\n\/\/ +20 is the deadzone, so it wont jiggle back and forth.
\n{
\nif (pos > 1)
\npos -= 1;
\nmyservo.write(pos);
\n}<\/p>\n

\/\/ Added some delay, increase or decrease if you want less or more speed.
\ndelay(10);
\n}<\/p><\/blockquote>\n

PS. If you got any questions etc, please take it in my forums post here.<\/a><\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"

[youtube=http:\/\/www.youtube.com\/watch?v=iEhX27ahreI&w=480&h=385] This is how to make a simple light tracker\/follower with the Arduino. The components you need apart from the Arduino is: 2x Photoresistors: “PHOTOCELL2 Miniature Photocell”. 2x 470 Ohms resistors. 1x Servo. And of course some wires, and a breadboard or two :). Next step is to wire it all up, I’ve made a […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[14,4],"tags":[16,178,172,176,26,95,111,174,179,177,175,61],"class_list":["post-103","post","type-post","status-publish","format-standard","hentry","category-arduino-electronics","category-electronics","tag-arduino","tag-avdvanced","tag-boarduino","tag-follower","tag-guide","tag-how","tag-ldr","tag-light","tag-make","tag-resistor","tag-tracker","tag-tutorial"],"blocksy_meta":{"styles_descriptor":{"styles":{"desktop":"","tablet":"","mobile":""},"google_fonts":[],"version":8}},"_links":{"self":[{"href":"https:\/\/stigern.net\/blog\/wp-json\/wp\/v2\/posts\/103","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/stigern.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/stigern.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/stigern.net\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/stigern.net\/blog\/wp-json\/wp\/v2\/comments?post=103"}],"version-history":[{"count":1,"href":"https:\/\/stigern.net\/blog\/wp-json\/wp\/v2\/posts\/103\/revisions"}],"predecessor-version":[{"id":306,"href":"https:\/\/stigern.net\/blog\/wp-json\/wp\/v2\/posts\/103\/revisions\/306"}],"wp:attachment":[{"href":"https:\/\/stigern.net\/blog\/wp-json\/wp\/v2\/media?parent=103"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/stigern.net\/blog\/wp-json\/wp\/v2\/categories?post=103"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/stigern.net\/blog\/wp-json\/wp\/v2\/tags?post=103"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}