Poppy Robot Core

This module is dedicated to remotely drive/query robots of the Poppy project family with a simple programmatic approach.

It has been done aiming to easily and automatically connect to any kind of/configuration of robot driven by the pypot library (a live discovering of the targeted robot is performed in order to get its structure aka aliases and motors).

Note it is based on the REST API exposed by the library pypot and then, depends on its release (see prerequisite).

Below a script example and its execution:

const { createPoppy, createScript } = require('poppy-robot-core')

const script = createScript()
  .select('all') // Select all motors
  .speed(150) // Set their speeds
  .stiff() // Make them programmatically "drivable"
  .position(0, true) // Then move all motors to position '0' degree.
  .select('m1','m2') // Next select only the motors 'm1' and 'm2'...
  .rotate(30) // and apply them a rotation by +30 degrees.

createPoppy().then(poppy => {
  poppy.exec(script)  
})

Or, using the ECMAScript 2017 async/await features:

const myFunction = async _ => {
  const poppy = await createPoppy()

  const script = createScript('all')
    .speed(150)
    .stiff()
    .position(0, true)
    .select('m1','m2')
    .rotate(30)

  await poppy.exec(script)
  // Other nice stuff with the poppy instance, next to this script execution  
  ...
}

This module is mainly based on the following objects:

• The Poppy object that handles:

  • The robot configuration (its structure, connection settings) and motor objects.
  • A script execution engine in order to perform action on motors

• The Motor Objects:

  • ExtMotorRequest that handles high level actions of the motors,
  • RawMotorRequest that handles the low-level rest requests to the motor register,
  • The RequestHandlerObject object in charge of all the requests to the REST API served by the pypot http server.

• The Script object in order to programmatically address and chain request to the motors,

• At last, the PoppyRequestHandler object in charge of querying/set the registers of motors.

Furthermore, it is provided with a bunch of high-level factories (see API.md) in order to facilitate use and settings of these objects such as settings connection parameters, automatically perform a live discovering of the target robot, etc... The configuration features are detailed here.

Table of Contents

• Prerequisite
• Install
• Configuring Robot Connection
• Write Scripts
• Examples
• API
• Known Limitations
• Credits
• License

Prerequisite

This module requires Poppy software ^v3.0.0 installed on robot.

Install

npm i poppy-robot-core

Configuring Robot Connection

By default, the poppy robot core performs a live discovering of the target robot using default connection settings for a Poppy Ergo Jr aka setting are respectively set to 'poppy.local' and 8080 for hostname and port of the pypot REST API.

Users can easily set their own settings through optionnal arguments of the createPoppy factory.

const { createPoppy } = require('poppy-robot-core')

let poppy = createPoppy(config)

where config is an object that handles user's configuration and then, overrides default ones.

As example:

let config = {
  connect: { // Connection settings
    hostname: poppy1.local,
    port: 8081
  }
}

where the connect property handles the connection settings (full description is available here),

Refer to the module API for further details or, in a easiest way, users can use the poppy-robot-cli module that provides a set of additional functionalities for such purpose (flags automatically appended to the node command line or serialized in a config file).

Write Scripts

The poppy robot core module is provided with a script execution engine and then, users, can write their own scripts to test complex combination of actions.

Such scripts are written in javascript language but all technical 'difficulties' have been hidden as much as possible and then, it allows users writing their own scripts without any particular knowledges/skills on javascript.

A set of examples of scripts are available into a dedicated repository. In this case too, their javascript-technical matters have been reduced insofar as possible or explained when needed.

At last, users can refers to the Script API for further details.

Examples

A set of scripts are available into a dedicated repository.

API

See API.md for more details.

Known Limitations

• This module have been only tested with the Poppy Ergo Jr (aka with a set of dynamixel XL-320). As it communicates with the robot via the REST API of the pypot library, it should be easily usable with any robots of the poppy family.

• position/rotate functions of Script/ExtMotorRequest: Awaiting end of movement i.e. setting the 'wait' argument to 'true' is based on the velocity of dynamixel XL-320 in order to compute/estimate the movement duration. The value is 0.666 degree per second (see documentation).

• Resolving 'poppy.local' is done looking for an ipv4 address and does not support ipv6 (yet?).

Credits

• Nicolas Barriquand (nbarikipoulos)

License

The poppy-robot-core is MIT licensed. See LICENSE.