{"id":46740,"date":"2023-04-22T01:00:45","date_gmt":"2023-04-22T06:00:45","guid":{"rendered":"https:\/\/www.bjultrasonic.com\/how-to-use-an-ultrasonic-sensor\/"},"modified":"2025-01-21T07:22:31","modified_gmt":"2025-01-21T12:22:31","slug":"how-to-use-an-ultrasonic-sensor","status":"publish","type":"post","link":"https:\/\/www.bjultrasonic.com\/vi\/how-to-use-an-ultrasonic-sensor\/","title":{"rendered":"H\u01b0\u1edbng d\u1eabn s\u1eed d\u1ee5ng c\u1ea3m bi\u1ebfn si\u00eau \u00e2m"},"content":{"rendered":"<p>C\u1ea3m bi\u1ebfn si\u00eau \u00e2m l\u00e0 m\u1ed9t thi\u1ebft b\u1ecb \u0111i\u1ec7n t\u1eed s\u1eed d\u1ee5ng s\u00f3ng \u00e2m thanh t\u1ea7n s\u1ed1 cao \u0111\u1ec3 \u0111o kho\u1ea3ng c\u00e1ch \u0111\u1ebfn m\u1ed9t v\u1eadt th\u1ec3. Ch\u00fang ho\u1ea1t \u0111\u1ed9ng d\u1ef1a tr\u00ean nguy\u00ean l\u00fd ph\u00e1t ra m\u1ed9t xung si\u00eau \u00e2m v\u00e0 \u0111o th\u1eddi gian \u0111\u1ec3 xung \u0111\u00f3 ph\u1ea3n x\u1ea1 tr\u1edf l\u1ea1i c\u1ea3m bi\u1ebfn.  Vi\u1ec7c hi\u1ec3u r\u00f5 c\u00e1ch s\u1eed d\u1ee5ng c\u1ea3m bi\u1ebfn si\u00eau \u00e2m m\u1edf ra nhi\u1ec1u \u1ee9ng d\u1ee5ng ti\u1ec1m n\u0103ng trong c\u00e1c l\u0129nh v\u1ef1c t\u1eeb robot, \u00f4 t\u00f4 \u0111\u1ebfn y t\u1ebf. B\u00e0i vi\u1ebft n\u00e0y s\u1ebd h\u01b0\u1edbng d\u1eabn chi ti\u1ebft c\u00e1ch s\u1eed d\u1ee5ng c\u1ea3m bi\u1ebfn si\u00eau \u00e2m m\u1ed9t c\u00e1ch hi\u1ec7u qu\u1ea3.<\/p>\n<h3>Nguy\u00ean l\u00fd ho\u1ea1t \u0111\u1ed9ng c\u1ee7a c\u1ea3m bi\u1ebfn si\u00eau \u00e2m<\/h3>\n<p>C\u1ea3m bi\u1ebfn si\u00eau \u00e2m th\u01b0\u1eddng g\u1ed3m m\u1ed9t b\u1ed9 ph\u00e1t v\u00e0 m\u1ed9t b\u1ed9 thu. B\u1ed9 ph\u00e1t ph\u00e1t ra m\u1ed9t xung si\u00eau \u00e2m ng\u1eafn. Khi xung n\u00e0y g\u1eb7p m\u1ed9t v\u1eadt c\u1ea3n, n\u00f3 s\u1ebd ph\u1ea3n x\u1ea1 l\u1ea1i v\u00e0 \u0111\u01b0\u1ee3c b\u1ed9 thu ghi nh\u1eadn.  Kho\u1ea3ng th\u1eddi gian t\u1eeb khi ph\u00e1t xung \u0111\u1ebfn khi nh\u1eadn \u0111\u01b0\u1ee3c t\u00edn hi\u1ec7u ph\u1ea3n x\u1ea1 \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 t\u00ednh to\u00e1n kho\u1ea3ng c\u00e1ch \u0111\u1ebfn v\u1eadt c\u1ea3n, d\u1ef1a tr\u00ean t\u1ed1c \u0111\u1ed9 \u00e2m thanh trong m\u00f4i tr\u01b0\u1eddng.<\/p>\n<h3>K\u1ebft n\u1ed1i c\u1ea3m bi\u1ebfn si\u00eau \u00e2m v\u1edbi vi \u0111i\u1ec1u khi\u1ec3n<\/h3>\n<p>Vi\u1ec7c k\u1ebft n\u1ed1i c\u1ea3m bi\u1ebfn si\u00eau \u00e2m v\u1edbi vi \u0111i\u1ec1u khi\u1ec3n th\u01b0\u1eddng kh\u00e1 \u0111\u01a1n gi\u1ea3n. H\u1ea7u h\u1ebft c\u00e1c c\u1ea3m bi\u1ebfn si\u00eau \u00e2m ph\u1ed5 bi\u1ebfn, v\u00ed d\u1ee5 nh\u01b0 HC-SR04, s\u1eed d\u1ee5ng b\u1ed1n ch\u00e2n k\u1ebft n\u1ed1i: VCC, GND, Trigger, v\u00e0 Echo.<\/p>\n<table class=\"table table-striped table-bordered\">\n<thead>\n<tr>\n<th>Ch\u00e2n<\/th>\n<th>Ch\u1ee9c n\u0103ng<\/th>\n<th>M\u00f4 t\u1ea3<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>VCC<\/td>\n<td>Ngu\u1ed3n \u0111i\u1ec7n d\u01b0\u01a1ng<\/td>\n<td>Th\u01b0\u1eddng l\u00e0 5V<\/td>\n<\/tr>\n<tr>\n<td>GND<\/td>\n<td>Ngu\u1ed3n \u0111i\u1ec7n \u00e2m<\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td>Trigger<\/td>\n<td>Ch\u00e2n k\u00edch ho\u1ea1t<\/td>\n<td>Nh\u1eadn xung \u0111\u1ec3 b\u1eaft \u0111\u1ea7u qu\u00e1 tr\u00ecnh \u0111o<\/td>\n<\/tr>\n<tr>\n<td>Echo<\/td>\n<td>Ch\u00e2n ph\u1ea3n h\u1ed3i<\/td>\n<td>Xu\u1ea5t xung c\u00f3 \u0111\u1ed9 r\u1ed9ng t\u1ec9 l\u1ec7 v\u1edbi th\u1eddi gian ph\u1ea3n x\u1ea1<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>Vi\u1ebft ch\u01b0\u01a1ng tr\u00ecnh \u0111i\u1ec1u khi\u1ec3n<\/h3>\n<p>\u0110\u1ec3 \u0111i\u1ec1u khi\u1ec3n c\u1ea3m bi\u1ebfn si\u00eau \u00e2m, b\u1ea1n c\u1ea7n vi\u1ebft ch\u01b0\u01a1ng tr\u00ecnh cho vi \u0111i\u1ec1u khi\u1ec3n.  M\u1ed9t v\u00ed d\u1ee5 \u0111\u01a1n gi\u1ea3n v\u1edbi Arduino:<\/p>\n<pre><code class=\"language-c++\">const int trigPin = 9;\nconst int echoPin = 10;\n\nvoid setup() {\n  Serial.begin(9600);\n  pinMode(trigPin, OUTPUT);\n  pinMode(echoPin, INPUT);\n}\n\nvoid loop() {\n  digitalWrite(trigPin, LOW);\n  delayMicroseconds(2);\n  digitalWrite(trigPin, HIGH);\n  delayMicroseconds(10);\n  digitalWrite(trigPin, LOW);\n\n  long duration = pulseIn(echoPin, HIGH);\n  float distance = duration * 0.034 \/ 2;\n\n  Serial.print(\"Khoang cach: \");\n  Serial.print(distance);\n  Serial.println(\" cm\");\n  delay(100);\n}<\/code><\/pre>\n<h3>X\u1eed l\u00fd d\u1eef li\u1ec7u v\u00e0 \u1ee9ng d\u1ee5ng<\/h3>\n<p>Sau khi nh\u1eadn \u0111\u01b0\u1ee3c d\u1eef li\u1ec7u kho\u1ea3ng c\u00e1ch t\u1eeb c\u1ea3m bi\u1ebfn, b\u1ea1n c\u00f3 th\u1ec3 x\u1eed l\u00fd d\u1eef li\u1ec7u n\u00e0y \u0111\u1ec3 ph\u1ee5c v\u1ee5 c\u00e1c \u1ee9ng d\u1ee5ng kh\u00e1c nhau. V\u00ed d\u1ee5, trong robot d\u00f2 \u0111\u01b0\u1eddng, d\u1eef li\u1ec7u kho\u1ea3ng c\u00e1ch \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 \u0111i\u1ec1u khi\u1ec3n robot tr\u00e1nh v\u1eadt c\u1ea3n. Trong h\u1ec7 th\u1ed1ng \u0111\u1ed7 xe t\u1ef1 \u0111\u1ed9ng, c\u1ea3m bi\u1ebfn si\u00eau \u00e2m gi\u00fap x\u00e1c \u0111\u1ecbnh kho\u1ea3ng c\u00e1ch \u0111\u1ebfn c\u00e1c xe kh\u00e1c.<\/p>\n<h3>L\u01b0u \u00fd khi s\u1eed d\u1ee5ng<\/h3>\n<p>C\u1ea7n l\u01b0u \u00fd m\u1ed9t s\u1ed1 y\u1ebfu t\u1ed1 \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn \u0111\u1ed9 ch\u00ednh x\u00e1c c\u1ee7a c\u1ea3m bi\u1ebfn si\u00eau \u00e2m nh\u01b0 nhi\u1ec7t \u0111\u1ed9, \u0111\u1ed9 \u1ea9m v\u00e0 g\u00f3c c\u1ee7a v\u1eadt c\u1ea3n.  Vi\u1ec7c hi\u1ec7u ch\u1ec9nh v\u00e0 l\u1ef1a ch\u1ecdn v\u1ecb tr\u00ed l\u1eafp \u0111\u1eb7t c\u1ea3m bi\u1ebfn ph\u00f9 h\u1ee3p l\u00e0 r\u1ea5t quan tr\u1ecdng \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o \u0111\u1ed9 ch\u00ednh x\u00e1c c\u1ee7a ph\u00e9p \u0111o.<\/p>\n<p>Vi\u1ec7c s\u1eed d\u1ee5ng c\u1ea3m bi\u1ebfn si\u00eau \u00e2m mang l\u1ea1i nhi\u1ec1u l\u1ee3i \u00edch trong vi\u1ec7c \u0111o kho\u1ea3ng c\u00e1ch kh\u00f4ng ti\u1ebfp x\u00fac.  T\u1eeb vi\u1ec7c hi\u1ec3u r\u00f5 nguy\u00ean l\u00fd ho\u1ea1t \u0111\u1ed9ng, c\u00e1ch k\u1ebft n\u1ed1i v\u00e0 l\u1eadp tr\u00ecnh, ng\u01b0\u1eddi d\u00f9ng c\u00f3 th\u1ec3 \u1ee9ng d\u1ee5ng c\u1ea3m bi\u1ebfn si\u00eau \u00e2m v\u00e0o nhi\u1ec1u d\u1ef1 \u00e1n v\u00e0 h\u1ec7 th\u1ed1ng kh\u00e1c nhau, t\u1eeb \u0111\u01a1n gi\u1ea3n \u0111\u1ebfn ph\u1ee9c t\u1ea1p. Hy v\u1ecdng b\u00e0i vi\u1ebft n\u00e0y \u0111\u00e3 cung c\u1ea5p cho b\u1ea1n nh\u1eefng ki\u1ebfn th\u1ee9c c\u1ea7n thi\u1ebft \u0111\u1ec3 b\u1eaft \u0111\u1ea7u s\u1eed d\u1ee5ng c\u1ea3m bi\u1ebfn si\u00eau \u00e2m m\u1ed9t c\u00e1ch hi\u1ec7u qu\u1ea3.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>C\u1ea3m bi\u1ebfn si\u00eau \u00e2m l\u00e0 m\u1ed9t thi\u1ebft b\u1ecb \u0111i\u1ec7n t\u1eed s\u1eed d\u1ee5ng s\u00f3ng \u00e2m thanh t\u1ea7n s\u1ed1 cao \u0111\u1ec3 \u0111o kho\u1ea3ng c\u00e1ch \u0111\u1ebfn m\u1ed9t v\u1eadt th\u1ec3. Ch\u00fang ho\u1ea1t \u0111\u1ed9ng d\u1ef1a tr\u00ean nguy\u00ean l\u00fd ph\u00e1t ra m\u1ed9t xung si\u00eau \u00e2m v\u00e0 \u0111o th\u1eddi gian \u0111\u1ec3 xung \u0111\u00f3 ph\u1ea3n x\u1ea1 tr\u1edf l\u1ea1i c\u1ea3m bi\u1ebfn. Vi\u1ec7c hi\u1ec3u r\u00f5<\/p>\n","protected":false},"author":1,"featured_media":26466,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6406],"tags":[],"class_list":["post-46740","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog","prodpage-classic"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.bjultrasonic.com\/vi\/wp-json\/wp\/v2\/posts\/46740","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.bjultrasonic.com\/vi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bjultrasonic.com\/vi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/vi\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/vi\/wp-json\/wp\/v2\/comments?post=46740"}],"version-history":[{"count":0,"href":"https:\/\/www.bjultrasonic.com\/vi\/wp-json\/wp\/v2\/posts\/46740\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/vi\/wp-json\/wp\/v2\/media\/26466"}],"wp:attachment":[{"href":"https:\/\/www.bjultrasonic.com\/vi\/wp-json\/wp\/v2\/media?parent=46740"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/vi\/wp-json\/wp\/v2\/categories?post=46740"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/vi\/wp-json\/wp\/v2\/tags?post=46740"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}