unleashed-firmware/applications/system/js_app/examples/apps/Scripts/gpio.js

let eventLoop = require("event_loop");
let gpio = require("gpio");

// initialize pins
let led = gpio.get("pc3"); // same as `gpio.get(7)`
let led2 = gpio.get("pa7"); // same as `gpio.get(2)`
let pot = gpio.get("pc0"); // same as `gpio.get(16)`
let button = gpio.get("pc1"); // same as `gpio.get(15)`
led.init({ direction: "out", outMode: "push_pull" });
pot.init({ direction: "in", inMode: "analog" });
button.init({ direction: "in", pull: "up", inMode: "interrupt", edge: "falling" });

// blink led
print("Commencing blinking (PC3)");
eventLoop.subscribe(eventLoop.timer("periodic", 1000), function (_, _item, led, state) {
    led.write(state);
    return [led, !state];
}, led, true);

// cycle led pwm
print("Commencing PWM (PA7)");
eventLoop.subscribe(eventLoop.timer("periodic", 10), function (_, _item, led2, state) {
    led2.pwmWrite(10000, state);
    return [led2, (state + 1) % 101];
}, led2, 0);

// read potentiometer when button is pressed
print("Press the button (PC1)");
eventLoop.subscribe(button.interrupt(), function (_, _item, pot) {
    print("PC0 is at", pot.readAnalog(), "mV");
}, pot);

// the program will just exit unless this is here
eventLoop.run();

// possible pins https://docs.flipper.net/gpio-and-modules#miFsS
// "PA7" aka 2
// "PA6" aka 3
// "PA4" aka 4
// "PB3" aka 5
// "PB2" aka 6
// "PC3" aka 7
// "PA14" aka 10
// "PA13" aka 12
// "PB6" aka 13
// "PB7" aka 14
// "PC1" aka 15
// "PC0" aka 16
// "PB14" aka 17

// possible modes
// { direction: "out", outMode: "push_pull" }
// { direction: "out", outMode: "open_drain" }
// { direction: "out", outMode: "push_pull", altFn: true }
// { direction: "out", outMode: "open_drain", altFn: true }
// { direction: "in", inMode: "analog" }
// { direction: "in", inMode: "plain_digital" }
// { direction: "in", inMode: "interrupt", edge: "rising" }
// { direction: "in", inMode: "interrupt", edge: "falling" }
// { direction: "in", inMode: "interrupt", edge: "both" }
// { direction: "in", inMode: "event", edge: "rising" }
// { direction: "in", inMode: "event", edge: "falling" }
// { direction: "in", inMode: "event", edge: "both" }
// all variants support an optional `pull` field which can either be undefined,
// "up" or "down"