Meld Homepage , Electronic PCB PCBA , Software .NET AVR PLM BOM , Network TCP UDP MQTT , Microcontrollers AVR ARM , Powersupplys Switchmode , Nursecall MC5000 CD2000
Author: Erik Leth Danielsen
How to Blink an LED on Raspberry Pi 3 Node.js
Short:My goal was to describe how to blink an LED mainly in node.js
Hardware:
Connect led+ to (GPIO Pin11) and led- to (GPIO Pin9 GND) through a 680R resistor.
gpio drawing
1 Nodejs
2 C
3 Pyton
4 Scratch
Software Nodejs:
Short:I have tried npm wiring-pi and WiringPi-Node, but it doesn't work on raspberry pi 3
It's based on wiringpi.h
Youtube wiring-pi nodejs
Instead i found npm rpio
It's based on bcm2835.h
Support In, Out, I2C, PWM, SPI
Get the Newest version of Nodejs and Npm:
Obs1 Update Pre installed nodejs and node-red, on a raspberry pi:$ update-nodejs-and-nodered
$ sudo apt-get install npm
See node-red
Obs2 Install nodejs and npm, on a raspberry pi:
$ sudo apt-get update
$ sudo apt-get upgrade
$ sudo apt-get install nodejs npm
Install rpio:
Download code:meldcorpio.zip
Install rpio option 1:
move meldcorpio folder to home/pi by ftp
$ cd meldcorpio
$ npm install 'This will install the dependencies described in package.json
Install rpio option 2:
move meldcorpio folder to home/pi by ftp
$ cd meldcorpio
$ npm install rpio
npm rpio
Code:
Blink Sync: (sleep bad programming)To run it
$ cd meldcorpio
$ node blinksync.js
//Get rpio object
var rpio = require('rpio');
//Set Pin 11 to Output Init Low
rpio.open(11, rpio.OUTPUT, rpio.LOW);
//Loop/Blink 5 times
for (var i = 0; i < 5; i++) {
/* On for 1 second */
rpio.write(11, rpio.HIGH);
rpio.sleep(1);
/* Off for half a second (500ms) */
rpio.write(11, rpio.LOW);
rpio.msleep(500);
}
To run it
$ cd meldcorpio
$ node blinkasync.js
console.log("press ctrl+c to exit");
//Get rpio object
var rpio = require('rpio');
//Set Pin 11 to Output Init Low
rpio.open(11, rpio.OUTPUT, rpio.LOW);
//Timer Toggle led every 500mSec
var state=false;
setInterval(blink, 500);
function blink()
{
if(state)rpio.write(11, rpio.HIGH);
else rpio.write(11, rpio.LOW);
state=!state;
}
To run it
$ cd meldcorpio
$ node tstloop.js
This will give a square wave 970KHz
sometimes 486Khz maybe node does something else in the background.
console.log("press ctrl+c to exit");
//Get rpio object
var rpio = require('rpio');
//Set Pin 11 to Output Init Low
rpio.open(11, rpio.OUTPUT, rpio.LOW);
//Loop Toggle led until ctrl+c
while(1) {
rpio.write(11, rpio.HIGH);
rpio.write(11, rpio.LOW);
}
See other language Benchmarking Gpio
Software C:
bcm2835.h:
Install:
bcm2835Code:
Blink Sync://Blink GPIO17 Pin11 GPIO_0
#include <stdio.h>
#include <bcm2835.h>
int main(void)
{
printf("press ctrl+c to exit\n");
if(!bcm2835_init())return 1;
bcm2835_gpio_fsel(17,BCM2835_GPIO_FSEL_OUTP);
while(1)
{
bcm2835_gpio_set(17);
bcm2835_delay(500);
bcm2835_gpio_clr(17);
bcm2835_delay(500);
}
return 0;
}
wiringpi.h:
Install:
Wiring PiCode:
Blink Sync://Blink GPIO17 Pin11 GPIO_0
#include <stdio.h>
#include <wiringPi.h>
int main(void)
{
printf("press ctrl+c to exit\n");
wiringPiSetup();
pinMode(0, OUTPUT);
while (1)
{
digitalWrite(0, HIGH);
delay(500);
digitalWrite(0, LOW);
delay(500);
}
return 0;
}
Software Python:
#Blink GPIO17 Pin11 GPIO_0
import RPi.GPIO as GPIO
import time
GPIO.setmode(GPIO.BOARD)
GPIO.setup(11, GPIO.OUT)
print "press ctrl+c to exit"
while True:
GPIO.output(11,True)
time.sleep(0.5)
GPIO.output(11,False)
time.sleep(0.5)
GPIO.cleanup()
Software Scratch:
Links:
node.js
Visual Studio Code
Benchmarking Gpio
| E-mail: info@meldco.dk
| VAT ID: 34576149
412773
