Android I/O Board

132 Pages·2015·27.29 MB·English

Edition 5/2015 | September & October 2015
www.elektormagazine.com
LEARN ● DESIGN ● SHARE
Android I/O Board
Control embedded electronics from
your Android phone or tablet
VFD Shield
for Arduino
AC/DC
Power Meter AC/DC Power Meter • Android I/O Board • Arduino 73 NP2re o1wRIg1en r1M aa L TdRmoaheedbmirvuss’is il enPeE wPgsrdor i&Cojteioj oePcuctnCrstsB:sess
Sound-Level Protector • ARM Micros and the and lots more
Analog World • Bike Inclinometer • BL600 e-BoB
• I2C and temperature sensor • Camelback Water
Level Indicator • Dimensioning a 3D Model • Err-lectronics • FFT Analysis in VB
• Hexadoku • I/O App (2) • Learn-‘n-Go Infrared Remote Controlled Dimmer
AAA Cell
• Over-Air LiPo Battery State Monitor • PIC Assembler Crash Course • Retronics:
Replacement
Preco 39 Years On • RPI Measures Electricity Consumption • Selected Gerber
on USB Files • Selenium Rectifiers • Single Wire LCD Interface • SMD Codes Revealed
• TinkerForge Bricks & Bricklets • USB Pseudo Battery • VFD Shield for Arduino •
Wireless I2C Sensor … and more
P C O S C I L LO S CO PE S
•10 MHz to 200 MHz bandwidth
Low cost •100 MS to 1 GS/s sampling
•8 bit resolution (12 bit enhanced)
•8 to 48 kS buffer memory
•USB powered
•Prices from $129 €99 £79
•2 or 4 analog channels + 16 digital
MSO •50 to 200 MHz bandwidth
•8 bit resolution (12 bit enhanced)
•64 to 512 MS buffer memory
•USB or AC adaptor powered
•Prices from $819 €659 £499
•20 MHz bandwidth
Eight
•80 MS/s sampling
•12 bit resolution (16 bit enhanced)
channels
•256 MS buffer memory
•USB powered
•Just $2305 €1845 £1395
•8, 12, 14, 15 & 16 bits all in one device
Flexible •60 to 200 MHz bandwidth
•250 MS/s to 1 GS/s sampling
rrreeesssooollluuutttiiiooonnn •8 to 512 MS buffer memory
•USB or AC adaptor powered
•Prices from $1155 €929 £699
•250 MHz to 1 GHz bandwidth
2 GS •5 GS/s sampling
•8 bit resolution (12 bit enhanced)
memory •256 MS to 2 GS buffer memory
•AC adaptor powered
•Prices from $3295 €2645 £1995
•DC to 20 GHz bandwidth
222000 GGGHHHzzz
•17.5 ps rise time
•16 bit, 60 dB dynamic range
sssaaammmpppllliiinnnggg
•AC adaptor powered
•Sig. gen, CDR, diff. TDR/TDT
•Prices from $14,995 €12,035 £9,085
Full software included as standard with serial bus decoding and analysis (CAN, LIN, RS232, I2C, I2S, SPI, FlexRay), segmented www.picotech.com/PS411
memory, mask testing, spectrum analysis, and software development kit (SDK) all as standard, with free software updates.
Five years warranty real time oscilloscopes, 2 years warranty sampling oscilloscopes.
Untitled-5 1 03/08/15 15:18
Edition 5/2015
Volume 41, No. 464 & 465
September & October 2015
ISSN 1947-3753 (USA / Canada distribution)
ISSN 1757-0875 (UK / ROW distribution)
Beyond Repair, never
www.elektor.com,
www.elektormagazine.com
Beyond Measurement
Elektor Magazine, English edition
is published 6 times a year by
Elektor International Media
If we have to accept that the electronic engineer is
78 York Street
London W1H 1DP, UK no longer the highly respected tech wizard on the
Phone: (+44) (0)20 7692 8344 block or street, always ahead of mass produced
consumer stuff on the shelves, and forever pushing
the performance of ‘his’ components, let’s content ourselves with doing measurements
Head Office:
and spreading the word on perfecting the art of measuring in the world of electronics.
Elektor International Media b.v.
PO Box 11 Even if your daughter’s 14-inch super VGA LCD monitor is not worth repairing as it would
NL-6114-ZG Susteren have been 20 years ago, there is value and satisfaction in hunting down the one elec-
The Netherlands trolytic capacitor with the bad ESR, replacing it, and finally moving that monitor to your
Phone: [phone]
workspace where an old PC is running programs Windows 8 does not like. As a spinoff
Fax: [phone]
there should be enough impressive numbers and Dilbert-ish commbuzzwords that can be
linked to your repair job, for your daughter to copy-paste a report with for her economics
USA / Canada Memberships:
classes, like “bathtub curve”, “costing estimate” and “parts resources”, as well as a ton of
Elektor USA
acronyms like DOA, FOA, BR, DIY. And she can have a new HDMI 23-inch LED screen.
P.O. Box 462228
Escondido, CA 92046 Your part of the job requires knowledge, basic test equipment and some confidence.
Phone: [phone] If designing a circuit is fun and creative, so is repairing and restoring one labeled BR
E-mail: [email protected] (beyond repair). In both cases, expert test gear is required and a deep knowledge of
Internet: www.elektor.com/member
what you are measuring. Browsing this edition of Elektor I hope you have as little dif-
UK / ROW Memberships: ficulty finding measurement-related articles as I had while compiling the lot and going
Please use London address through the pre-press phases: the PIC Assembler Course this month touches on analog
E-mail: [email protected] circuitry, this intrinsically involves ADC’ing real-world quantities; FFT Analysis on page
Internet: www.elektor.com/member
30 should be obvious; just like AC/DC Power Meter on page 46; and of course the RPi
Electricity Consumption Meter (page 59). Challenging articles, all three. At a less ambi-
Advertising & Sponsoring: tious level at least electronically there’s the Camelback Water Level Indicator (page 76)
Johan Dijk
and the Bike Inclinometer (page 80).
Phone: [phone]
Although all projects mentioned here appear designed for a purpose, the articles hope-
E-mail: [email protected]
fully contain elements that widen, trigger or channel your own creativity. Our humble
www.elektor.com/advertising
contributions this month include how-to’s of power metering the proper way, water level
Advertising rates and terms available on
request. metering the cheap way (with two 4060’s), and LiPo voltage metering, hey, over-air!
Measure it — understand it — stay in the lead!
Copyright Notice
The circuits described in this magazine are for domestic
Enjoy reading this edition
and educational use only. All drawings, photographs,
printed circuit board layouts, programmed integrated Jan Buiting, Editor-in-Chief
circuits, disks, CD-ROMs, DVDs, software carriers, and
article texts published in our books and magazines
(other than third-party advertisements) are copyright
Elektor International Media b.v. and may not be repro- The Circuit
duced or transmitted in any form or by any means,
including photocopying, scanning and recording, in Editor-in-Chief: Jan Buiting
whole or in part without prior written permission from
Publisher: Don Akkermans
the Publisher. Such written permission must also be
obtained before any part of this publication is stored Membership Manager: Raoul Morreau
in a retrieval system of any nature. Patent protection
Client Executive: Cindy Tijssen
may exist in respect of circuits, devices, components
etc. described in this magazine. The Publisher does not International Editorial Staff: Harry Baggen, Jaime González-Arintero,
accept responsibility for failing to identify such pat- Denis Meyer, Jens Nickel
ent(s) or other protection. The Publisher disclaims any
responsibility for the safe and proper function of read- Laboratory Staff: Thijs Beckers, Ton Giesberts, Luc Lemmens,
er-assembled projects based upon or from schematics, Clemens Valens, Jan Visser
descriptions or information published in or in relation
Graphic Design & Prepress: Giel Dols
with Elektor magazine.
Online Manager: Daniëlle Mertens
© Elektor International Media b.v. 2015
Printed in the USA Printed in the Netherlands
www.elektormagazine.com September & October 2015 3
this edition
VFD Shield for Arduino
Volume 41 – Edition 5/2015 Nixie tubes have enjoyed renewed popularity for some time with retro
& vintage enthusiasts and on the Internet there are countless designs
No. 464 & 465 September & October 2015
for Nixie clocks to be found. In Elektor too, we have published several
projects with Nixie tubes in recent years. However, in this project we do
not use Nixies, but instead make use of VFD (Vacuum Fluorescent Display)
tubes. These are somewhat different from the well-known Nixie tubes and
6 Elektor Circuits & Connections are currently gaining popularity.
This Arduino shield has been designed
34 Industry: News & New Products
from an educational viewpoint and
36 Industry: therefore does not have any SMD
Man & Machine: components or parts that are
the Distance that Brings us Closer difficult to obtain.
38 Welcome to Elektor Labs
54
104 Elektor Store
LEARN DESIGN SHARE
9 Welcome to the LEARN section
10 From 8 to 32 Bits: ARM Microcontrollers for
Beginners (5): The Analog World
15 Peculiar Parts: Selenium Rectifiers
16 DesignSpark Mechanical CAD Tips & Tricks
(2): Dimensioning a 3D Model
18 PIC Assembler Crash Course (2): Mini dev
board and electronic die
24 I/O App (2): Control external hardware with
a Windows app
29 Tips & Tricks: Safety Tip for AVR Control-
lers; Variometer Tuning
30 FFT Analysis in VB
LEARN DESIGN SHARE
59
40 Welcome to the DESIGN section
41 Learn-‘n-Go Infrared Remote Controlled 76 Camelback Water Level Indicator
Dimmer
80 Bike Inclinometer
46 AC/DC Power Meter
84 Wireless I2C Sensor
54 VFD Shield for Arduino
88 Arduino Sound-Level Protector
59 RPI Measures Electricity Consumption
92 Single Wire LCD Interface
64 Android I/O Board (1)
96 Over-Air LiPo Battery State Monitor
71 BL600 e-BoB (4):
The I2C port and the temperature sensor 102 USB Pseudo Battery
4 september/oktober 2015 www.elektormagazine.nl
46
magazine
LEARN DESIGN SHARE
AC/DC
111 Welcome to the SHARE section
Power Meter
112 Review: German Brickwork
(TinkerForge Bricks & Bricklets)
This project consists of a measurement
board holding the ADS1115-eBoB 116 Escaped from the Labs: Selected Gerber
together with a small filter board. Good Files
isolation is guaranteed between the power
118 What’s Hot at dot Labs:
connections (AC or DC) on the primary side and the measurement signal
It’s been a hot, hot summer
outputs on the secondary side. The signals on the secondary side are
digitized by the ADS1115, and the digital data is fed to an Arduino Uno with 120 Err-lectronics:
an Elektor Prototyping Shield. The displayed quantities for AC are effective
UART/RS-232 Data Logger; J2B Synthesizer;
power, voltage and current, as well reactive power and power factor.
USB Hub; ARM Course (3); USB-to-
Multiprotocol Converter; AVR Port Toggle;
TCA580 Gyrator
122 Web Scouting: SMD Codes Revealed
124 Retronics: Preco 39 Years On
Android I/O Board
128 Elektor World News
Part 1 130 Play & Win: Hexadoku
Control embedded electronics
from your Android phone or tablet next edition
64
MEASSY Audio Measurement System
This compact device combines a high-quality microphone
preamplifier with phantom power supply with a small audio
output stage in a single enclosure. You guessed it: MEASSY is
geared to loudspeaker system measurements.
Compact 60-watt Audio Amp
This audio output stage is an all-discrete design. The circuit
contains only commonly available components, is easy to
build, takes up little board space, yet delivers fine sound
quality.
Red Pitaya Does FM Stereo Radio
This article underscores the sheer versatility of the Red Pi-
taya development system. By adding a small prestage, and
doing efficient digital editing, FM broadcasts (stereo and
RDS) can be decoded.
124
Edition 6 / 2015 covering November & December is published
on October 15, 2015.
Delivery of printed copies to Gold members subject to transport.
Contents and article titles subject to change.
www.elektormagazine.nl september/oktober 2015 5
Elektor Circuits &
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Untitled-1 1 16/04/15 07:35 PCBservice EN for magazine.indd 1 04/06/15 07:39
Welcome to the LEARN section
E By Jens Nickel
@ the Maker Faire
R
By the time you Brick ‚R‘ Knowledge (www.brickrknowledge.de);
A read this the last these well designed modules look particularly use-
discarded coffee ful for (but not just for) the teaching of electron-
cup, wire clipping ics. Another interesting project is the ‘SenseBox’.
H and solidified solder This IoT sensor kit is also targeted at education
blob will already be and includes an Internet platform to collect data
swept up and con- from numerous environmental sensors measuring
S signed to the trash air pressure, temperature, humidity and incident
after this year’s light levels. Two versions of the system are avail-
Maker Faire held in able; one for education and another for DIY use.
Hannover, Germany.
I would like to thank
all our colleagues at
Make: for ensuring
this event was such
a success. I don’t know how, but they even man-
aged to arrange good weather! The hands-on activ-
ities were particularly inspiring for all the (really)
N
young engineers in attendance. The eight solder-
ing stations at our workshops (photo) were only
allowed to cool down once the last ‘Electronic Dice’
G
kit had been fully assembled.
It was also a good opportunity to check out many
of the latest developments, boards and projects
I
that were on show. One product that caught my
S
eye was the system of hardware modules from
E
Learning to Program (2)
D
I have already received a number of emails in from page 30). Another reader suggested the
connection with the ‘(High)School Board’ sug- low-cost Launchpad range of development kits
gestion and the ‘Learning to program’ editorial, from TI. Once again I was grateful for the com-
many thanks for those, your feedback is always ments from another reader who, like me, wanted
welcomed. Amongst other things a reader pointed a board programmable using C# supporting both
me toward ‘Project Oberon’ by Niklaus Wirth. I PC and embedded environments that could be
must admit I had not been aware of this FPGA- programmed by using just one programming lan-
based processor hardware (see for example www. guage. Perhaps we should begin with a Raspberry
xilinx.com/publications/archives/xcell/Xcell91.pdf, Pi 2 running Windows — quite intriguing.
N
And then there was…
R
Another episode from the ongoing ‘stupid-mis- compiler worked its magic without any errors but
takes-made-while-designing-and-developing’ saga. something here didn’t look right; the power LED
A I would of course prefer to keep these to myself on the MIDI module did not light up when it is
but that way nobody would profit from my errors. plugged into the Xmega board. I chose a second
Finally I got to porting the MIDI Analyzer (featured board, this time it worked. A quick look at the sche-
E
in the last edition) firmware from the Arduino Uno matic revealed the reason why: The first board was
to the Elektor Xmega Webserver board. My EFL con- missing a jumper! Sometime in the past I had, for
L figurator had been set up so that with just a single some reason, removed it. The lesson here is that
key press an Xmega project is generated with all it always pays to double check the documentation
the necessary files and the hardware-independent before you bring a board back into use again. This
source code for the MIDI analyzer. Now all I need is especially true when you are totally confident you
to do is change the number of the UART interface already know the board inside out!
(150319)
in the code which talks to the MIDI module. The
www.elektormagazine.com September & October 2015 9
learn design share
The analog world
From 8 to 32 bits: ARM Microcontrollers for Beginners (5)
By Viacheslav Gromov (Germany)
So far in this course we have looked at the SAM D20’s wide range of digital peripheral blocks; now it is
the turn of the analog circuitry. It will come as no surprise to readers with experience from the world of
8-bit microcontrollers that we will be looking in detail at both the analog-to-digital converter (ADC) and
analog comparator (AC); and to those we also add the digital-to-analog converter (DAC).
Our SAM D20 includes a powerful ADC of the inputs are designed to be used in steps of approximately 0.0002 V. Other
with a resolution selectable between with internal sources such as the DAC functions available include amplifying the
eight, ten and twelve bits. Its structure or temperature sensor. As can be seen input signal with a gain of between 0.5
is illustrated in Figure 1. The same rule from the block diagram, the ADC always and 16, and a window comparison mode
of thumb applies as in the case of eight- requires a non-inverting and an inverting to monitor whether the measured values
bit microcontrollers: the lower the reso- input and will convert the voltage differ- fall within a specified range. An inter-
lution, the shorter the conversion time. ence between these two inputs into a rupt can be triggered if the limits are
The SAM D20’s ADC can manage up to digital value. The inverting input can of exceeded. The ADC can be configured
350,000 conversions per second, while in course simply be connected to ground. to carry out a single conversion or to
oversampling mode it can achieve a res- The ADC also requires a reference volt- carry out continuous conversions when
olution of 16 bits. As many as 32 inputs age, of which several are available. If, for started. Further information on the ADC
to the converter are available, of which example, the voltage reference is 1 V, the can be found in the datasheet starting
up to ten can be used as inverting inputs maximum voltage the ADC can measure on page 481.
and 25 as non-inverting inputs (some will also be 1 V; if the resolution is set to
being able to function as either). Some 12 bits, then the output will be expressed First experiments with the ADC
The ADC is an important peripheral block,
and so we of course want to see what
it can do in practice. Figure 2 shows a
CTRLA WINCTRL simple circuit that can be built using an
AVGCTRL WINLT LM335 analogue temperature sensor. The
two components can easily be soldered
SAMPCTRL WINUT
INPUTCTRL together in mid-air (see Figure 3). To
EVCTRL OFFSETCORR obtain accurate readings the cable should
SWTRIG GAINCORR be kept reasonably short.
The temperature sensor is easy to use
ADC0
... and exhibits good linearity [1]. We would
ADCn like to measure the temperature using the
INT.SIG
ADC POST ADC and output the readings once per
RESULT
PROCESSING
second to the PC over the virtual serial
ADC0
... port (UART). The project ‘ADC Test1’
ADCn shows how this is accomplished: like all
INT.SIG
the code accompanying this article it is
INT1V CTRLB available for download at [2]. Supplemen-
INTVCC
VREFA tary documents including code listings are
VREFB
PRESCALER also available from the same location.
REFCTRL At the beginning of the main file are the
commands to create the instance struc-
tures for the U(S)ART and for the ADC,
Figure 1. Outline structure of the analog-to-digital converter (ADC). the function prototypes, the declaration
10 September & October 2015 www.elektormagazine.com