High performance GPIO tool kit for raspberry pi, including quadrature_decoder, DC motor control, soft PWM, buttons, etc. Based on c wiringpi.
npm install perf-gpio``
npm install perf-gpio --save
Note: perf-gpio depend on dynamic-linked wiringPi at run-time, make sure you have wiringPi installed (/usr/local/lib/libwiringPi.so file).
js
var onoff = require('perf-gpio').onoff;// wiring-pi 2 = GPIO27 = PIN13
var led = onoff(2);
led.set(1);
`onoff -- flash
js
var onoff = require('perf-gpio').onoff;// wiring-pi 2 = GPIO27 = PIN13
var led = onoff(2);
var current = false;
setTimeout(timeout, 1000);
function timeout() {
setTimeout(timeout, 1000);
current = !current;
led.set(current);
console.log(current);
}
`button -- simple read
js
var button = require('perf-gpio').button;// wiring-pi 3 = GPIO22 = PIN15
var b = button(3, button.PUD_UP); // use raspberry pi build-in 50k pull-up resistor
setTimeout(timeout, 1000);
function timeout() {
setTimeout(timeout, 1000);
var current = b.get();
console.log(current);
}
`button -- callback
js
var button = require('perf-gpio').button;// wiring-pi 3 = GPIO22 = PIN15
var b = button(3, button.PUD_UP);
b.watch(function(err, status) {
console.log(status? 'UP' : 'DOWN');
});
`inputBank (setup multiple pins, read all at once, as bit mask)
js
var inputBank = require('perf-gpio').inputBank();
// wiring-pi 25/24/23 = GPIO26/19/13 = PIN37/35/33
var bank = inputBank([25, 24, 23], "PUD_DOWN");setTimeout(timeout, 1000);
function timeout() {
setTimeout(timeout, 1000);
var val = bank();
// bit mask: bit 0 <= wp25, bit 1 <= wp24, bit 2 <= wp23
console.log(val);
}
`
* Note: support batch read, but don't support edge-triggered callback. If you need callback, consider using button.
* Note: inputBank and button can share the same pin. Under the hood they are both "input" mode, thus no conflict.
quadrature_decoder
` js
var qd = require('perf-gpio').quadrature_decoder;// quadrature_decoder you need 2 pins, phase A and B
// wiringpi PIN 0 and 1, maps to BCM GPIO 17 and 18
var counter = qd(0,1);
timeout();
function timeout() {
setTimeout(timeout, 1000);
console.log(counter.getCounter());
}
`led (DMA-PWM basic)
js
var led = require('perf-gpio').led();
var pin = led(25); // wiringPi 25, GPIO 26
pin(0.5); // 50% on
`led (DMA-PWM cnt.)
js
var led = require('perf-gpio').led();
var pin = led(25); // wiringPi 25, GPIO 26
pin(1);setTimeout(function() {
pin(0.5);
setTimeout(function() {
pin.close(); // turn off led before quit
led.shutdown(); // shutdown DMA device before quit
process.exit(0);
}, 2000);
}, 2000);
`DC motor control
js
var motor = require('perf-gpio').motor();
// Need 2 pin to control a DC motor (forward/backword)
// you need a H-bridge module to drive a DC motor
var pin = motor(23, 25);pin(-0.5); // anywhere range from [-1.0, +1.0]
function timeout() {
pin.close(); // turn off motor before quit
motor.shutdown(); // shutdown DMA device before quit
process.exit(0);
}
setTimeout(timeout, 2000);
`
Note: DC motor and LED shares the same DMA channel (14 for pi2/3/zero and 7 for pi4), 5ms cycle with 2us step size.Servo control
js
var servo = require('perf-gpio').servo();
var pin = servo(29); // wiringpi_25=gpio_21=Phys_40pin(1500); // 1.5ms (mid)
setTimeout(function () {
pin(500); // 0.5ms (min)
setTimeout(function () {
pin(2500); // 2.5ms (max)
setTimeout(function () {
pin(1500); // 1.5ms (mid)
setTimeout(function () {
servo.shutdown();
process.exit(0);
}, 500);
}, 1000);
}, 1000);
}, 1000);
`
Note: Servo runs on it's own DMA channel (13 for pi2/3/zero and 6 for pi4), 20ms cycle with 10us step size.Clock Output
js
var clockOut = require('./index').clockOut();// wiring-pi 22 = GPIO6 = PIN31
var pinNum = 22;
var pin = clockOut(pinNum);
pin.setFeq(10000); // 10kHz
.....
pin.shutdown();
``MIT