README

@fustaro/pololu-maestro-controller

Node Pololu Maestro servo controller

USB Chained Mode (confirmed working on Windows 10, RPI 4 and RPI Zero W)

npm install @fustaro/pololu-maestro-controller

Create a ServoModel, specific to the brand and model of a particular servo

const servoModel = new ServoModel({
    pwmRange: { min: 1000, natural: 1500, max: 2000 },
    angleRange: { min: -60, natural: 0, max: 60 },
    speed: 0.1,
    servoDirection: ServoDirection.HIGHER_PWM_CLOCKWISE
});

Create Servo instances, specific to each servo you want to control

const servo = new Servo({
    servoModel: servoModel,
    centerOffsetPwm: 0,
    channel: 0,
    flipDirection: false
});

Create your MaestroServoController

import { getOrCreateMaestroController } from '@fustaro/pololu-maestro-controller';

const controller = getOrCreateMaestroController(uniqueHardwareName, portName, channels);

//uniqueHardwareName: A unique reference to a given Maestro, e.g. 'Maestro_COM4' 
//                    The ServoControllerFactory will only ever return a single
//                    ServoController for a given uniqueHardwareName

//portName: The USB port to find and connect the Maestro on. 
//          On Windows, this will typically be 'COM1', 'COM2', etc
//          On RPI, this will typically be '/dev/ttyACM0' or '/dev/ttyUSB0'

//channels: The amount of channels this Maestro supports (6, 12, 18, 24 etc)

Note on Raspberry Pi running multiple Pololu Maestros from multiple USB ports, you may need to reference the ports by hardware ID, for example;

const port_m1 = '/dev/serial/by-id/usb-Pololu_Corporation_Pololu_Mini_Maestro_12-Channel_USB_Servo_Controller_********-if00';
const port_m2 = '/dev/serial/by-id/usb-Pololu_Corporation_Pololu_Mini_Maestro_12-Channel_USB_Servo_Controller_********-if00';

const servoController_m1 = getOrCreateMaestroController('Maestro_M1', port_m1, 12);
const servoController_m2 = getOrCreateMaestroController('Maestro_M2', port_m2, 12);

To get your unique hardware ids, just plug in your Maestros and run;

ls /dev/serial/by-id/

Run your servo

controller.setAngleDegrees(servo, 40);

Sample scripts

import { beginAngleLoop, stopAngleLoop } from '@fustaro/pololu-maestro-controller/dist/samples/angleLoop';

const controller = <create your controller>;
const servo = <create your servo>;

//this will set your servo to 40°, 0°, -40°, 0°, etc - changing every 500ms
beginAngleLoop(controller, servo, [40, 0, -40, 0], 500);

import { beginSinLoop, stopSinLoop } from '@fustaro/pololu-maestro-controller/dist/samples/sinLoop';

const controller = <create your controller>;
const servo = <create your servo>;

//this will run your servo in a sin loop, +/- 40°
//updating every 15ms and doing 2 full loops every second
beginSinLoop(controller, servo, 40, 15, 2);

Usage no npm install needed!