Linux Format - UK (2020-03)

http://www.techradar.com/pro/linux March 2020 LXF260 41

Raspberry Pi projects

borgs) and optionally can be fitted with four ultrasonic

distance sensors, which you can use to practice, say,

safer parking.

The borgs, and many other robots, are sold as build-

it-yourself kits. Depending on the particular kit, this

might be quite an involved process, involving small

parts, soldering and possibly swearing (and sheepishly

having to order replacement parts). Building the Diddy

takes a couple of hours from start to finish.

Having constructed it we wanted to know more

about what it could do. Not content with making

glorious hardware, PiBorg also provides some great

code examples to get you started. These will need some

tweaking to work on other hardware, but they should

give you some idea of how to talk to the hardware in

Python. Robot kits will provide scripts to deal with all the

low-level communication – in our case this is all done

through the ThunderBorg.py file (which you can peruse

at http://bit.ly/LXF260piborg). This handles all the

raw I2C coding, so you don’t need to worry about that,

and provides more human functions, like SetMotor1() ,

which sets the speed of the left-hand-wheels.

Home assistant

We’re pretty cynical about voice assistants here at LXF

Towers. Our (nameless) sister magazines rant and rave

about the latest Alexa additions and how they make

ordering from Amazon even easier. They quietly forgive

the chaos that ensues when Siri’s name is spoken on

the television, as all the fruity phones within earshot

frantically start offering to help. Tech pundits wax lyrical

on the importance of shoving a network stack deep into

every single appliance in your house so that it can be

“smart”, so that the “smart” appliances can all chatter

among themselves about their dumb masters.

But all things have their uses, and much of the

shadier side of voice assistants can be obviated by the

power of open source. The Mycroft (https://mycroft.ai)

Mark 1 (launched in 2016) and Mark 2 (coming soon)

are Raspberry Pi-powered home assistants that we

don’t mind listening to us.

You probably already know that Sherlock Holmes

had an elder brother called Mycroft. You may even be

aware that in Heinlein’s classic The Moon Is A Harsh

Mistress, the HOLMES FOUR computer that accidentally

became self aware was named Mycroft (shortened to

Mike). In case you weren’t, that’s where the Mycroft

home assistant gets its name. Don’t worry though,

despite our best efforts we couldn’t get our Mycroft to

become sentient, and at no point did we feel threatened

by Mycroft.

You don’t need to buy the official hardware to use

Mycroft, as it can run on any good Linux distribution.

Alternatively you can download Picroft (a ready-to-go

image of Mycroft for the Pi) and run that right away.

Voice recognition and intent recognition are

reasonably taxing CPU-wise, so you’ll need at least a Pi

2 to run Picroft. Even that will struggle, though, and the

official word (see https://mycroft.ai/documentation/

picroft) is to use a Pi 3. That way you also won’t have to

worry about getting Wi-Fi working, since Picroft is

(currently) based on Raspbian Stretch that already has

those drivers built in.

Since the Pi’s onboard audio doesn’t have any kind

of analogue input, you’ll need a microphone. We used

the reasonably fancy Seeed ReSpeaker mic array, which

has four microphones so that it can (with some work)

determine the direction of an audio source. You’ll also

need some kind of speaker. This could connect either to

the 3.5mm analogue output or via USB, or via HDMI if

your display has speakers.

Mycroft’s core Skills (as Mycroft’s powers are

known) include a basic Hello World example, which

responds to its title “How are you” and, graciously,

“Thank you”. This is intended to introduce people to

programming their own skills. For fun and games try

asking it to sing a song or tell a joke. You can also ask

it things like how to spell words or to check stock

prices. But thanks to the community, a raft of

other skills are available (further jokes are also

available in the Better Joke skill). One of the

most popular skills for Mycroft is

openHAB (home automation bus),

which is a platform for talking to all

kinds of home appliances under a unified web

interface. It can communicate with a multitude of

different devices, including other smart home platforms

such as Nest.

Mycroft’s glorious

ASCII splash

screen. Yet another

opportunity

for Cool Retro

Term to make an

appearance.

The UltraBorg that connected our ultrasonic sensors can connect

PWM servos too. It communicates over the Pi’s I2C bus

MYCROFT WILL OBEY

“Despite our best efforts we

couldn’t get our Mycroft to become

sentient, and at no point did we

feel threatened by Mycroft.”

3332March 0 h2rSenshSnigtom March 2020LXF260 41

Raspberry Pi projects

borgs) and optionally can be fitted with four ultrasonic
distance sensors, which you can use to practice, say,
safer parking.
The borgs, and many other robots, are sold as build-
it-yourself kits. Depending on the particular kit, this
might be quite an involved process, involving small
parts, soldering and possibly swearing (and sheepishly
having to order replacement parts). Building the Diddy
takes a couple of hours from start to finish.
Having constructed it we wanted to know more
about what it could do. Not content with making
glorious hardware, PiBorg also provides some great
code examples to get you started. These will need some
tweaking to work on other hardware, but they should
giveyousomeideaofhowtotalktothehardwarein
Python.Robotkitswillprovidescriptstodealwithallthe
low-levelcommunication–inourcasethisisalldone
throughtheThunderBorg.pyfile(whichyoucanperuse
athttp://bit.ly/LXF260piborg).Thishandlesallthe
rawI2Ccoding,soyoudon’tneedtoworryaboutthat,
andprovidesmorehumanfunctions,likeSetMotor1() ,
which sets the speed of the left-hand-wheels.

Home assistant
We’re pretty cynical about voice assistants here at LXF
Towers. Our (nameless) sister magazines rant and rave
about the latest Alexa additions and how they make
ordering from Amazon even easier. They quietly forgive
the chaos that ensues when Siri’s name is spoken on
the television, as all the fruity phones within earshot
frantically start offering to help. Tech pundits wax lyrical
on the importance of shoving a network stack deep into
every single appliance in your house so that it can be
“smart”, so that the “smart” appliances can all chatter
among themselves about their dumb masters.
But all things have their uses, and much of the
shadier side of voice assistants can be obviated by the
power of open source. The Mycroft (https://mycroft.ai)
Mark 1 (launched in 2016) and Mark 2 (coming soon)
are Raspberry Pi-powered home assistants that we
don’t mind listening to us.
You probably already know that Sherlock Holmes
had an elder brother called Mycroft. You may even be
aware that in Heinlein’s classic The Moon Is A Harsh
Mistress, the HOLMES FOUR computer that accidentally
became self aware was named Mycroft (shortened to
Mike). In case you weren’t, that’s where the Mycroft
home assistant gets its name. Don’t worry though,
despite our best efforts we couldn’t get our Mycroft to
become sentient, and at no point did we feel threatened
by Mycroft.

You don’t need to buy the official hardware to use

Mycroft, as it can run on any good Linux distribution.

Alternatively you can download Picroft (a ready-to-go

image of Mycroft for the Pi) and run that right away.

Voice recognition and intent recognition are

reasonably taxing CPU-wise, so you’ll need at least a Pi

2 to run Picroft. Even that will struggle, though, and the

official word (see https://mycroft.ai/documentation/

picroft) is to use a Pi 3. That way you also won’t have to

worry about getting Wi-Fi working, since Picroft is

(currently) based on Raspbian Stretch that already has

those drivers built in.

Since the Pi’s onboard audio doesn’t have any kind

ofanalogueinput,you’llneedamicrophone.Weused

thereasonablyfancySeeedReSpeakermicarray,which

has four microphones so that it can (with some work)

determine the direction of an audio source. You’ll also

need some kind of speaker. This could connect either to

the 3.5mm analogue output or via USB, or via HDMI if

your display has speakers.

Mycroft’s core Skills (as Mycroft’s powers are

known) include a basic Hello World example, which

responds to its title “How are you” and, graciously,

“Thank you”. This is intended to introduce people to

programming their own skills. For fun and games try

asking it to sing a song or tell a joke. You can also ask

it things like how to spell words or to check stock

prices. But thanks to the community, a raft of

other skills are available (further jokes are also

available in the Better Joke skill). One of the

most popular skills for Mycroft is

openHAB (home automation bus),

which is a platform for talking to all

kinds of home appliances under a unified web

interface. It can communicate with a multitude of

different devices, including other smart home platforms

such as Nest.

Mycroft’s glorious

ASCII splash

screen. Yet another

opportunity

for Cool Retro

Term to make an

appearance.

The UltraBorg that connected our ultrasonic sensors can connect

PWM servos too. It communicates over the Pi’s I2C bus

MYCROFT WILL OBEY

“Despite our best efforts we

couldn’t get our Mycroft to become

sentient, and at no point did we

feel threatened by Mycroft.”