Matrix - RGB LED

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1 Introduction

Matrix-RGB LED.png
  • The Matrix-RGB_LED is a RGB LED module. It has a 2.54mm pitch pin-header in which 5V is power supply, GND is ground, and R,G,B are connected to the LED’s red, green and blue pins.
  • The inputs to Pin R, G and B can be either GPIO signals or PWM signals. The signal level can be either 3.3V or 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 or PWM input, 3.3/5V, LED lightness controllable via PWM
  • Small
  • 2.54 mm pitch pin-header
  • PCB dimension(mm): 16 x 24

Matrix-RGB LED PCB.png

  • 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:
Matrix-RGBLED_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:
Matrix-RGB_LED_nanopi2

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.
Matrix-RGBLED_nanopi_m2

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

7 Resources