How to build an effective IoT demo with OSGi - Derek Baum & Walt Bowers

Copyright © 2005 - 2016 Paremus Ltd.May not be reproduced by any means without express permission. All rights reserved.October 2016 www.paremus.com

OSGi Community Event 2016co-located at

EclipseCon Europe 2016

How to build an effective IoT demo with OSGi

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Copyright © 2005 - 2016 Paremus Ltd.May not be reproduced by any means without express permission. All rights reserved.October 2016 2

about: me [email protected]

• Studied Electronic Engineering

• Only ever worked as a Software Engineer:- Unix - 1980- System III, System V, Solaris

- C/C++ - 1982-

- Linux - 1990- 0.9

- Java - 1995- 1.0

- OSGi - 2006- R4

• Until IoT came along..- First time I’ve used a soldering iron for over 30 years!

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Copyright © 2005 - 2016 Paremus Ltd.May not be reproduced by any means without express permission. All rights reserved.October 2016 www.paremus.com

OSGi IoT Demo

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about: presentation

• What makes an effective IoT demo?

• Bottom-up review of OSGi IoT demo:- Mechanical Engineering (Lego®)- Electronic Engineering (Things)- Software Engineering (OSGi)

• Problems encountered• Resolutions & extensions• Questions?


What makes an effective IoT demo?

• A cool UI?


A cool UI?



• A cool UI?

• or some Things?


Some things?



• A cool UI?

• or some Things?Things are more compelling as you can see them physically doing stuff.Things draw attention to your demo/product.You can then demonstrate your cool UI :-)


June 2015: Radio Controlled Cars?


July 2015: Remote Controlled Trains?

• Goal – Demonstrate OSGi as a viable technology to control low level IO on the device and high level control in the cloud


Lego® Train


Lego® Train: Actuators & Sensors

What actuators & sensors do we need?

• Actuators - perform some action (write-only)

- setSpeed(train#, speed)

- setLight(train#, on_off)

- setTrackSwitch(switch#, normal_alternate)

- setSignal(signal#, colour)

• Sensors - report some status (read-only)

- getLocation(train#)


Lego® Train: What’s in the box?

• Working system:

• Infrared remote controlled battery-powered train

- 4 channel, capable of controlling speed and lights of 4 trains

✓setSpeed()

✓setLight()

• Track

• Lego® bricks :-)


Lego® Train: What’s missing?

• Track signals

• Track switch actuators

• Train location sensors


Hardware Engineering

Lego® Engineering


Lego® Engineering


Lego® VIP member



✓Track signals

✓Track switch actuators

✗Train location sensors


Electronic Engineering

Thing Engineering


Train location sensors?

• No Lego® location sensors available :-(

• Mechanical or magnetic switches?

- too low tech?; can’t distinguish multiple trains

• Scan barcode on train?

- TBD

• Read RFID tag on train?

- cheap RFID readers available

- use 6 fixed readers and an RFID tag on each train


MF-RC522 RFID reader


MF-RC522 RFID reader - testing



✓Track signals

✓Track switch actuators

✓Train location sensorsMF-RC522 RFID readers seem to work OK• supported on Raspberry PI using SPI bus• tested using Python RFID reader program• range not great, 1-2cm, but should be OK


Actuator & sensors

• Train speed & lights - infrared

• Track signals - high power LEDs

• Track switch actuators - Lego® motors

• Train location sensors - RFID


Lego® Infrared protocol?


Lego® Infrared protocol?

Protocol consists of 38 kHz cycles:Low bit length = 16 x 1/38K = 421 usHigh bit length = 27 x 1/38K = 711 usStart bit length = 45 x 1/38K = 1184 usStop bit length = 45 x 1/38K = 1184 us

sub-ms timings require some real-time capability


LIRC - www.lirc.com

http://www.lirc.com


LIRC <-> Lego® RC

• LIRC enables control of Lego® RC functions simply by writing the correct sequence of “pulses” to /dev/lirc0.

• We converted an example C program into Java- http://www.nishioka.com/train/control.c

http://www.nishioka.com/train/control.c


Actuator & sensor drivers?

• Raspberry Pi GPIO cannot drive high-power LEDs or motors

• We need to use “driver” chips

Raspberry Pi GPIO connector


LED driver: ULN2003A €0.50


Motor driver: SN754410 €2.00

Copyright © 2005 - 2016 Paremus Ltd.May not be reproduced by any means without express permission. All rights reserved.October 2016

IoT Demo Dual Segment Controller Hardware 20-July-2015

2 x MF-RC522 RFID Readerconnected to GPIO SPI Bus

ULN2003ALED driver for signals

Raspberry Pi 2 GPIO connector

Motor driver for track switches

40

Dual segment driver


Attach to Raspberry Pi


Fritzing


Fabricate


Attach to Raspberry Pi


fritzing.org

http://fritzing.org


Software Engineering

OSGi Engineering


Service model

Remote services


Deployment model


SignalSegmentImpl


Problems

Problems?


Problems: RFID readers

MF-RC522 RFID readers seem to work OK• range not great, 1-2cm, but should be OK

Not OK!• unreliable, many not working at all• range insufficient for reliable train detection• help!


Problems: RFID readers

•Use mechanical micro-switches instead of RFID

•Detect micro-switches by creating code to read GPIO pin


Extensions

Extensions?


RFID #2

Despite failure of RFID#1, it still seemed like the most viable detection mechanism.Previously, we did not research available RFID devices, and just used the cheapest, most readily available device.RFID#2• use a better RFID reader• mount reader on train• use multiple passive RFID tags on track


RFID #2 - Better RFID Reader

• use a better RFID reader• RMD6300• works at 125kHz vs

13Mhz for old reader• provides serial output• still cheap: €5


RFID #2 - Expensive Tags - >€1.00 each


RFID #2 - Cheap Tags - €0.10 each


RFID #2 - Perfect Tags - <€0.50 each


RFID #2 - Better RFID Reader

• Produces serial output• How to mount in train?• Use bluetooth!


RFID #2 - Mount on train


Service model

Kura

MQTT


Extensions - Hardware refactoring


Summary

Summary


Summary

• What makes an effective IoT demo?

• Bottom-up review of OSGi IoT demo:- Mechanical Engineering (Lego®)- Electronic Engineering (Things)- Software Engineering (OSGi)

• Problems encountered• Resolutions & extensions• Questions?


Q & A

Questions?


Q & A


www.paremus.com @Paremus [email protected]

[email protected]

http://fritzing.org/projects/raspberry-pi-rfidmotorled-driver

https://github.com/osgi/osgi.iot.contest.sdk

mailto:[email protected]

http://fritzing.org/projects/raspberry-pi-rfidmotorled-driver

https://github.com/osgi/osgi.iot.contest.sdk

How to build an effective IoT demo with OSGi - Derek Baum & Walt Bowers

Technology

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