Difference between revisions of "Matrix - LED"
From FriendlyELEC WiKi
| Line 9: | Line 9: | ||
* 体积小巧， 带固定孔，方便嵌入到外壳 | * 体积小巧， 带固定孔，方便嵌入到外壳 | ||
* 2.54mm排针接口，接线方便，通用性强 | * 2.54mm排针接口，接线方便，通用性强 | ||
| + | |||
| + | ==使用方法== | ||
| + | ===连接=== | ||
| + | *连接到Tiny4412 SDK (1506) | ||
| + | ::将配件S针脚连接到GPIO PIN1, V接5V，G接地 | ||
| + | |||
| + | ===Linux下的C示例=== | ||
| + | <syntaxhighlight lang="c"> | ||
| + | #include <stdio.h> | ||
| + | #include <unistd.h> | ||
| + | #include "libfahw.h" | ||
| + | |||
| + | #define LED_BLINK_TIMES 10 | ||
| + | |||
| + | int main(int argc, char ** argv) | ||
| + | { | ||
| + | int ledPin = TINY4412_GPIO_PIN1; | ||
| + | int i = 0; | ||
| + | int ret = -1; | ||
| + | |||
| + | if ((ret = exportGPIOPin(ledPin)) == -1) { | ||
| + | printf("exportGPIOPin(%d) failed\n", ledPin); | ||
| + | } | ||
| + | if ((ret = setGPIODirection(ledPin, GPIO_OUT)) == -1) { | ||
| + | printf("setGPIODirection(%d) failed\n", ledPin); | ||
| + | } | ||
| + | |||
| + | for (i = 0; i < LED_BLINK_TIMES; i++) { | ||
| + | if (i % 2) { | ||
| + | ret = setGPIOValue(ledPin, GPIO_HIGH); | ||
| + | } else { | ||
| + | ret = setGPIOValue(ledPin, GPIO_LOW); | ||
| + | } | ||
| + | if (ret == -1) { | ||
| + | printf("setGPIOValue(%d) failed\n", ledPin); | ||
| + | } | ||
| + | printf("LED blinking times %d\n", i); | ||
| + | sleep(1); | ||
| + | } | ||
| + | unexportGPIOPin(ledPin); | ||
| + | return 0; | ||
| + | } | ||
| + | </syntaxhighlight> | ||
| + | |||
| + | ===编译并运行示例=== | ||
| + | <syntaxhighlight lang="bash"> | ||
| + | git clone http://github.com/friendlyarm/fa-hardware.git | ||
| + | cd fa-hardware | ||
| + | cd demo | ||
| + | cd matrix-led | ||
| + | make | ||
| + | </syntaxhighlight> | ||
| + | 将编译生成的LED通过ftp上传到开发板上运行即可测试。 | ||
| + | |||
| + | ==相关资料== | ||
Revision as of 02:57, 24 July 2015
Contents
1 介绍
File:Led.jpg
LED
一个直径为5mm的LED，3-Pin 2.54mm排针，V接电源，G接地，S信号通过一个三极管放大控制LED的导通或关闭。您可以向S输出静态的高低电平信号，也可以输出变化的PWM信号，信号电平可以是3.3V或5V。当您向S输出高电平时LED以最大亮度发光，低电平就完全熄灭，可变占空比的PWM信号可以调节发光的亮度。我们提供红、绿、蓝三种颜色的配件供您购买。
2 特性
- GPIO或PWM控制，3.3/5V电平，亮度通过PWM可调
- 体积小巧， 带固定孔，方便嵌入到外壳
- 2.54mm排针接口，接线方便，通用性强
3 使用方法
3.1 连接
- 连接到Tiny4412 SDK (1506)
- 将配件S针脚连接到GPIO PIN1, V接5V，G接地
3.2 Linux下的C示例
#include <stdio.h> #include <unistd.h> #include "libfahw.h" #define LED_BLINK_TIMES 10 int main(int argc, char ** argv) { int ledPin = TINY4412_GPIO_PIN1; int i = 0; int ret = -1; if ((ret = exportGPIOPin(ledPin)) == -1) { printf("exportGPIOPin(%d) failed\n", ledPin); } if ((ret = setGPIODirection(ledPin, GPIO_OUT)) == -1) { printf("setGPIODirection(%d) failed\n", ledPin); } for (i = 0; i < LED_BLINK_TIMES; i++) { if (i % 2) { ret = setGPIOValue(ledPin, GPIO_HIGH); } else { ret = setGPIOValue(ledPin, GPIO_LOW); } if (ret == -1) { printf("setGPIOValue(%d) failed\n", ledPin); } printf("LED blinking times %d\n", i); sleep(1); } unexportGPIOPin(ledPin); return 0; }
3.3 编译并运行示例
git clone http://github.com/friendlyarm/fa-hardware.git cd fa-hardware cd demo cd matrix-led make
将编译生成的LED通过ftp上传到开发板上运行即可测试。
