Matrix - Buzzer

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1 Introduction

Buzzer

We utilize a 5V passive buzzer. To drive this buzzer an oscillating source is needed. Pin V is power, Pin G is grounded and Pin S is PMW signal input. Pin S is connected to a triode to turn on/off the buzzer. A PWM signal can be either 3.3V or 5V and the buzzer's sound will vary accordingly.

2 Features

• 5V Power Supply
• 3.3V/5V PWM
• Tiny, easy to be used in various situations
• 2.54mm spacing pin

3 How To

3.1 Connection

• Connect to Tiny4412 SDK (1506)

Firstly you need to remove the jumper on BP1_EN on the Tiny4412 SDK 1506 carrier board

Please connect Pin S to GPIO PIN1, V to 5V and G grounded

3.2 Code Sample in C Under Linux

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include "libfahw.h"
 
int parseCmd(int argc, char **argv, int *pin, int *Hz, int *duty)
{
    int num = atoi(argv[1]);
    int hz = atoi(argv[2]);
    int dt = atoi(argv[3]);
 
    if (hz<0) {
        return -1;
    }
    if (dt<0 || dt>1000) {
        return -1;
    }
    switch(num) {
    case 0:
        *pin = TINY4412_PWM0; 
        break;
    case 1:
        *pin = TINY4412_PWM1;
        break;
    default:
        printf("Unsupported pin TINY4412_PWM%d\n", num);
        num = 0;
        *pin = TINY4412_PWM0;
    }
    *Hz = hz;
    *duty = dt;
    printf("Using config: pin=PWM%d freq=%dHz duty=%d\n", num, hz, dt);
    return 0;
}
 
int main(int argc, char ** argv)
{
    int pin = TINY4412_PWM0;
    int Hz;
    int duty;
 
    if (argc == 4) {
        if (parseCmd(argc, argv, &pin, &Hz, &duty) == -1) {
            return -1;
        }
    } else {
        Hz = 1000;
        duty = 500;
        printf("Usage:%s PWM[0~1] freq duty[0~1000]\n", argv[0]);
        printf("Using default config: pin=PWM0 freq=%dHz duty=%d\n", Hz, duty);
    }
 
    if (PWMPlay(pin, Hz, duty) == -1) {
        printf("Fail to output PWM\n");
    }  
    printf("Press enter to stop PWM\n");
    getchar();
    PWMStop(pin);
    printf("Stopped PWM\n");
    return 0;
}

3.3 Compile and Run

git clone http://github.com/friendlyarm/fa-hardware.git
cd fa-hardware
cd demo
cd matrix-buzzer
make

Copy your compiled bin to your board and you are ready to go.