Difference between revisions of "Matrix - RGB LED"
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For more details about this APIs called in this code sample refer to [[Matrix API reference manual]] <br> | For more details about this APIs called in this code sample refer to [[Matrix API reference manual]] <br> | ||
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Revision as of 15:32, 23 June 2016
Contents
1 Introduction
- Matrix-RGB_LED是一个RGB发光二极管模块。5-Pin 2.54mm排针,V接电源,G接地,R、G、B引脚分别控制二极管发出红、绿、蓝三种颜色的光,或者组合发出混色光。
- 您可以向R、G、B引脚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R、G、B引脚输出高电平时LED以最大亮度发光,低电平就完全熄灭;向R、G、B引脚输出可变占空比的PWM信号可以调节R、G、B颜色光发光的亮度,从而形成多种颜色的混色光。
2 Features
- GPIO或PWM控制,3.3/5V电平,亮度通过PWM可调
- Small
- 2.54 mm pitch pin-header
- PCB dimension(mm): 16 x 24
- Pin Description:
Pin | Description |
GND | Ground |
5V | Supply Voltage 5V |
R | Red |
G | Green |
B | Blue |
3 工作原理
- RGB_LED的内部封装了三颗不同颜色的灯珠,三个灯珠的阳极或者阴极并联,当给另外三个引脚施加控制信号时,对应的LED就会亮起。当两种或三种LED亮起时,根据三原色原理,会组成其他颜色的光。施加PWM信号时,不同占空比的PWM信号可以调节R、G、B颜色光发光的亮度,从而组合成多种颜色。
4 Applications
4.1 Connect to NanoPi M1
Refer to the following connection diagram to connect the module to the NanoPi M1:
Connection Details:
Matrix-RGBLED | NanoPi M1 |
R | Pin7 |
G | Pin8 |
B | Pin10 |
V | Pin4 |
G | Pin6 |
4.2 Connect to NanoPi 2
Refer to the following connection diagram to connect the module to the NanoPi 2:
Connection Details:
Matrix-RGBLED | NanoPi 2 |
R | Pin7 |
G | Pin8 |
B | Pin10 |
V | Pin4 |
G | Pin6 |
4.3 Connect to NanoPi M2 / NanoPi 2 Fire
Refer to the following connection diagram to connect the module to the NanoPi M2/ NanoPi 2 Fire.
Connection Details:
Matrix-RGBLED | NanoPi M2 |
R | Pin7 |
G | Pin8 |
B | Pin10 |
V | Pin4 |
G | Pin6 |
4.4 Connect to NanoPC-T2
Refer to the following connection diagram to connect the module to the NanoPC-T2:
Matrix-RGBLED_NanoPC-T2
Connection Details:
Matrix-RGBLED | NanoPC-T2 |
R | Pin15 |
G | Pin16 |
B | Pin17 |
V | Pin29 |
G | Pin30 |
5 Compile & Run Test Program
Boot your ARM board with Debian and copy the matrix code:
$ apt-get update && apt-get install git $ git clone https://github.com/friendlyarm/matrix.git
If your cloning is done successfully a "matrix" directory will be generated.
Compile and install Matrix:
$ cd matrix $ make && make install
Run test program:
$ matrix-rgb_led
Note: this module is not plug and play therefore before running the module please make sure it is connected to an ARM board.
Here is what you should observe:
Set RGB LED: 0 Set RGB LED: 1 Set RGB LED: 2 Set RGB LED: 3 Set RGB LED: 4 Set RGB LED: 5 Set RGB LED: 6 Set RGB LED: 7
You will see the LED displaying different colors.
6 Code Sample
This Matrix code sample can work with all the ARM boards mentioned in this module's wiki. The name of this code sample is "matrix-rgb_led". Here is its source code:
int main(int argc, char ** argv) { int ret = -1; int val, board; if ((board = boardInit()) < 0) { printf("Fail to init board\n"); return -1; } if (board == BOARD_NANOPI_T2) { ledPin1 = GPIO_PIN(15); ledPin2 = GPIO_PIN(16); ledPin3 = GPIO_PIN(17); } if ((ret = exportGPIOPin(ledPin1)) == -1) { printf("exportGPIOPin(%d) failed\n", ledPin1); } if ((ret = setGPIODirection(ledPin1, GPIO_OUT)) == -1) { printf("setGPIODirection(%d) failed\n", ledPin1); } if ((ret = exportGPIOPin(ledPin2)) == -1) { printf("exportGPIOPin(%d) failed\n", ledPin2); } if ((ret = setGPIODirection(ledPin2, GPIO_OUT)) == -1) { printf("setGPIODirection(%d) failed\n", ledPin2); } if ((ret = exportGPIOPin(ledPin3)) == -1) { printf("exportGPIOPin(%d) failed\n", ledPin3); } if ((ret = setGPIODirection(ledPin3, GPIO_OUT)) == -1) { printf("setGPIODirection(%d) failed\n", ledPin3); } signal(SIGINT, intHandler); for (val = 0; val < 8; val++) { printf("Set RGB LED: %x\n", val); setRGBLED(val); usleep(1000 * 1000); } unexportGPIOPin(ledPin1); unexportGPIOPin(ledPin2); unexportGPIOPin(ledPin3); return 0; }
For more details about this APIs called in this code sample refer to Matrix API reference manual