PiCraftZero

PiCraftZero is:

• a universal remote control supporting virtual (web) and physical (handheld) controllers.

• a collection of gpiozero compatible Python components for:

  • receiving joystick updates
  • auto discovering and controlling i2c based motor & servo add-ons for the Raspberry Pi
  • 'steering mixers' for converting joystick axis values to motor speeds
  • websocket messaging

• a camera streaming server and web client for single or dual cameras where:

  • remote stereo viewing can use a mobile phone with Google Cardboard
  • the mobile phones gyro can control a pan/tilt camera mount

• cross platform, tested to work on Pi (Jessie & Jessie-Lite), Linux, Mac & Windows.

• able to run without any additional hardware (e.g. Pi HATs or joypads), handy for dev & testing.

• able to use desktop connected gamepads and mobile paired gamepads if your PC or mobile webbrowser supports the HTML5 Gamepad API

Example

This is example is for robot that has 2 motors. It can be control using game controllers and web browsers on most desktop and mobile platforms. If a camera is attached then video can be streamed to the client.

#!/usr/bin/python3

from picraftzero import Joystick, Wheelbase, steering_mixer, start

joystick= Joystick()                         
motors = Wheelbase(left=0, right=1)  

motors.source = steering_mixer(joystick.values)

start()

A commented version of the code can be found here along with other examples.

Once picraftzero is installed (see below), download and run the example using:

git clone https://github.com/WayneKeenan/picraftzero.git
cd picraftzero/examples
python3 tiny4wd.py

Screenshots

Below is a 'screenshot' of PiCraftZero running in the Chromium browser on a RaspberryPi fitted with a Pimoroni HyperPixel touchscreen. The remote control is communicating via WiFi to the Coretec Robotics Tiny4WD robot.

You can watch a Coretech Tiny4WD in action off-road here. Thanks to Brian Corteil

You can watch a selection of physical, virtual controllers and remote camera viewer (inc. GoogleCardboard VR viewer) in this video:

You can watch PiCraftZero in action on the iPad, an Android tablet and a Mac in this video:

Status

PiCraft is in beta and all feedback is welcomed. For any feature requests, questions and bug reports please raise a GitHub issue

This README is currently the only documentation fit for end-user consumption, please ignore the 'docs' folder as that is mostly a collection of badly formatted notes, and is very much a work in progress.

Please note that whilst PiCraftZero is in beta the API's may change, breaking backwards compatibility.

Quick Start - Installing on a Pi

This quick start kicks the tyres to check that basic things are ok, this will run standlone on many platforms but please refer to the notes section, as this is more fun when installed on a Pi with the Pi Camera and i2c enabled.

To install:

sudo apt-get update
sudo apt-get install -y libav-tools python3-picamera python3-ws4py python3-smbus python3-dev python3-pip
sudo pip3 install evdev cap1xxx picraftzero

To run the default PiCraftZero behaviour which supports controlling 2 motors and 2 servos, if available, run:

python3 -m picraftzero

Open a web browser, on almost any platform or browser, to: http://raspberrypi.local:8000/ or http://<IP>:8000/

Click on the 'Single Camera' icon in the center of the toolbar.

The right hand side of the screen is virtual joystick used for motor control by default. The left hand side of the screen is virtual joystick used for pan/tilt control by default, if available.

If you move the joysticks around then you should see logging info on the console and if motors and servos connected they should move.

Notes

Raspbian prerequisites:

Use raspi-config to:

• Enable Camera,
• Enable i2c
• Set GPU memory to at least 128Mb

Hardware prerequisites

PiCraft zero has been written to work on many popular platforms with or without the physical robot hardware.

It uses auto-detection of common motor and servo controllers and will resort to using a 'just log a message' fallback if no actual hardware is detected.

A list of the hardware that can be used:

• A Motor Controller (optional) e.g. Pimoroni Explorer pHAT or 4tronix Piconzero
• A Servo Controller (optional) e.g. Pimoroni PanTilt HAT or 4tronix Piconzero
• Camera (optional)
• Joypad (optional) e.g. RockCandy
• Desktop, laptop, smartphone or tablet with a webbrowser

If your using a Piconzero pHAT then attach the pan servo to servo 0 and the tilt servo to servo 1.

If you need to flip the image because the camera image is upside down edit the PicraftZero config file:

sudo nano /etc/picraftzero.cfg

Add these lines:

[camera]
hflip=yes
vflip=yes

Enhancements

There are a few useful changes that can be made:

• running as a service and
• using an alternative camera streaming service which has higher framerates than the bundled default in PiCraftZero

Install UV4L Camera Service

To use a camera streaming service which has low latency you need to:

• Install and run uv4l RaspiCam service
• Update PiCraftZero config

Install uv4l (Raspbian Jessie only):

curl http://www.linux-projects.org/listing/uv4l_repo/lrkey.asc | sudo apt-key add -
echo 'deb http://www.linux-projects.org/listing/uv4l_repo/raspbian/ jessie main' | sudo tee --append /etc/apt/sources.list > /dev/null
sudo apt-get update
sudo apt-get install -y uv4l uv4l-raspicam  uv4l-raspicam-extras   uv4l-server

Install uv4l (Raspbian Stretch only):

curl http://www.linux-projects.org/listing/uv4l_repo/lpkey.asc | sudo apt-key add -
deb http://www.linux-projects.org/listing/uv4l_repo/raspbian/stretch stretch main
sudo apt-get update
sudo apt-get install -y uv4l uv4l-raspicam  uv4l-raspicam-extras   uv4l-server

Backup the orignal uv4l config file and download a customised uv4l config which has some optimsed settings:

sudo mv /etc/uv4l/uv4l-raspicam.conf /etc/uv4l/uv4l-raspicam.conf.original 
sudo wget https://raw.githubusercontent.com/WayneKeenan/picraftzero/master/picraftzero/resources/config/uv4l-raspicam.conf  -O /etc/uv4l/uv4l-raspicam.conf

Then run:

sudo systemctl restart uv4l_raspicam
sudo systemctl status uv4l_raspicam

Check the output and look for: Active: active (running)

You can verify UV4L working by going to http://raspberrypi.local:8080/stream

You will need to stop and re-run the PiCraftZero script.

If you want to stop the camera service type:

sudo systemctl stop uv4l_raspicam

Configure PiCraftZero camera URL

Add user defined config to use the UV4L server:

sudo wget https://raw.githubusercontent.com/WayneKeenan/picraftzero/master/picraftzero/resources/config/picraftzero_snippet_uv4l.cfg  -O /etc/picraftzero.cfg

Stop and re-run the default script:

python3 -m picraftzero

Press reload in your web browser.

Running as a service

The default PicraftZero script can be run as a systemd service.

It's also possible to configure PiCraftZero to use your own script, TODO:link.

Systemd setup

Download, enable and start the PiCraftZero systemd service by running:

sudo wget https://raw.githubusercontent.com/WayneKeenan/picraftzero/master/picraftzero/resources/config/picraftzero.service  -O /etc/systemd/system/picraftzero.service
sudo systemctl enable picraftzero
sudo systemctl start picraftzero

To show the service status run:

sudo systemctl status -l picraftzero

To show the service log file run:

sudo journalctl -u picraftzero

Disabling the service

To disable the service run:

sudo systemctl stop picraftzero
sudo systemctl disable picraftzero

Updates

When a new picraftzero module is published on PyPi run the following to update and restart:

sudo pip3 install --upgrade picraftzero
sudo systemctl restart picraftzero
sudo systemctl status -l picraftzero

To revert to a specific version, change the version at the end of the line in this example:

sudo pip3 install picraftzero==0.1.6