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Making IoT device
with Ruby
HASUMI Hitoshi
Monstar Lab, Matsue office
Nov. 2, 2018 (day 2)
RubyWorld Conference 2018
Kunibiki Messe, Shimane
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Information
mrubycKaigi#1 on Oct. 31, 2018 (the day
before yesterday)
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Information
Polish Ruby users group sent me an
invitation
they want me to talk about mruby/c
I'm going to have several talks and
workshops in May 2019
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Information
Polish Ruby users group sent me an
invitation
they want me to talk about mruby/c
I'm going to have several talks and
workshops in May 2019
RubyWorld!!!
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Making IoT device with Ruby
PoC product for a Sake brewery, 旭日酒造
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Making IoT device with Ruby
prototype for mass production
you can see the device at Monstar-lab's booth
downstairs today (Nov. 1-2)
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Making IoT device with Ruby
what does `with Ruby` mean?
not only CRuby
not only mruby/c, too
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Making IoT device with Ruby
what does `with Ruby` mean?
not only CRuby
not only mruby/c, too
but also RubyWorld
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About me
Monstar Lab / Matsue office (now hiring!)
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About me
HASUMI Hitoshi（羽角 均） @hasumikin
finished master's degree in architecture
department
majored in the history of Italian architecture
became a programmer at 35 years old
neither a computer specialist nor an
electricity expert
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Technology stack of IoT
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Technology stack of IoT (1/2)
TCP/IP
cloud service
RDB and KVS
server programming
mobile programming
security
test
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Technology stack of IoT (2/2)
high school physics electricity and
transistor
microcontroller and peripherals like
UART, I2C, ADC, etc.
circuit and PCB artwork
soldering and wiring
3D CAD for housing
suppliers
firmware programming
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Understanding the business
Sake brewing process and Sake itself
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The most thing you should know is
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The most thing you should know is
Ruby on Rails
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Ruby on Rails
tells you what a good API is
tells you what a reinventing the wheel is
tells you what an ecosystem is
tells you what a web service is
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Technology stack of IoT (1/2) again
✓TCP/IP
✓cloud service
✓RDB and KVS
✓server programming
✓mobile programming
✓security
✓test
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Ruby on Rails
gives you time on digging into
technologies other than the server app
gives you wings
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Technology stack of IoT (2/2) again
✓high school physics electricity and
transistor
✓microcontroller and peripheral
interfaces like UART, I2C, ADC, etc.
✓circuit and PCB artwork
✓soldering and wiring
✓3D CAD
✓suppliers
✓firmware programming
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Microcontroller
I use microcontrollers instead of single
board computers like Raspberry Pi
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Microcontroller, upside
starts immediately right after plugged in
end users, brewery workers in my case,
can use it simply
you can narrow security issue list
many a malware aims at linux or windows
platform as a target
you don't need to consider unnecessary
deamon
neither need to do `apt upgrade` nor `yum
update`
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Microcontroller, upside
low energy
rarely overheated
many choices of power supply
mass production
you can choose appropriate chipset
(number of GPIOs, memory size, etc.) for
your application
cost advantage for parts supply and
subcontractor manufacturing
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Microcontroller, downside
less resource
CPU, memory
hard to be soldered
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Sake IoT project
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Sake IoT project
IoT system for Asahi-shuzo（旭日酒造）
delivered to actual brew work in January
2018
devices post temperature of Sake
materials in brewing, surrounding
temperature and humidity to the cloud
then, those data are displayed on the
smartphone app
the firmware written in mruby/c
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what does mruby/c mean?
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what does mruby/c mean?
compact
concurrent
capability
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Sake IoT project
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So many factors to be troubled in IoT
circuit design, soldering, wiring,
peripheral equipments, network...
hard to find why the application doesn't
work well
in addition to above, I introduced a new
layer of mruby/c
one year ago, mruby/c was yet young,
had bugs and insufficiency
(now it is enough good)
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So many factors to be troubled in IoT
then, was mruby/c bad?
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So many factors to be troubled in IoT
then, was mruby/c bad? - NO
IoT at work makes you hurry, imagine
you have to go alternately to dark 10℃
storage cellar and humid 35℃
manufacturing room
brewery workers run around
you have to amend your firmware with
your small laptop in 10 minutes
you will thank Ruby's descriptiveness and
agility
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Does IoT at work make you hurry?
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Does IoT at work make you hurry?
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Pre-prototyping
preparation is the most important thing
you have to confirm if a part works as
same as the datasheet
sometimes it is different
you can prepare with Ruby
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Pre-prototyping
Raspberry Pi & CRuby are great for pre-
prototyping
use breadboard or make PCB for test like this
photo
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Pre-prototyping
ex) CRuby for serial communication test
# notice this is CRuby for RasPi
require 'rubyserial'
require 'timeout'
sp = Serial.new '/dev/serial0', BAUDRATE, 8 # match with your instrument
loop do
puts '[command]'
command = gets
sp.write command.sub("\n", "\r") # replace LF if needed
sleep 0.1
result = ''
begin
Timeout.timeout(10) do
loop do
line = sp.read(128)
break if line == '' && result != ''
result << line
sleep 0.1
puts '=> ' + result
rescue Timeout::Error
puts 'timeout!'
ennnnd
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Pre-prototyping
ex) CRuby for serial communication test
$ serial_communication_test.rb
[command]
# command
AT
=> OK
# response
[command]
# command
AT+CIMI
=> 123456789012 # response
[command]
# command
AT+XXX
=> error
# response
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Pre-prototyping
then, you can copy and paste CRuby
snippet to mruby/c source
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Firmware programming with mruby/c
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Firmware programming with mruby/c
Ruby power
string operations
encapsulation (object oriented)
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Firmware programming with mruby/c
# ex) string operations
#
# concatenation
parameter = 'name=' + name + '&age=' + age.to_s
# => name=hasumikin&age=43
# substitution
'what_a_wonderful_world'.tr('_', '-')
# => what-a-wonderful-world
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Firmware programming with mruby/c
# ex) encapsulation (object oriented)
class LoggerBase
def info(line)
write(:info, line)
ennd
class LoggerBLE < LoggerBase
def initialize(*args)
@ble = BluetoothLowEnergy.bind_characteristic(args[0])
end
def write(log_level, line)
@ble.notify(line)
ennd
class LoggerFlashROM < LoggerBase
def initialize(*args)
@rom_io = RomFileStream.open('/log.txt', 'w')
end
def write(log_level, line)
@rom_io.write_ln(line)
ennd
logger = LoggerBLE.new(:log) /* or */ logger = LoggerFlashROM.new
logger.info('this is log')
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Firmware programming with mruby/c
you must write both mruby and C
C for microcontroller I/O
mruby for business logic
mruby/c seems like a thin wrapper for C
two sides of the same coin:
you have to write C that directly communicate
with peripherals
you can fall back to C anytime you get stuck
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Find more information on
rubykaigi.org/2018/presentations/
hasumon.html
shimane.monstar-lab.com/hasumin
follow twitter.com/mrubyc_jp
ITOC and I are planning to make
workshops of mruby/c
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Conclusion
Thank Ruby
from pre-prototyping to production
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Conclusion
Thank Ruby
from pre-prototyping to production
Thank Rails
full of really important things
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Conclusion
Thank Ruby
from pre-prototyping to production
Thank Rails
full of really important things
Thank Sake
