Table Of ContentTable of Contents
1 Introduction .................................................................................. 9
1.1 The Arduino Project . 10
1.2 Book Structure and Target Audience ............................................ 10
2 Structure and Function of the Hardware ........................................ 11
2.1 Lots to Choose From: Arduino Versions ........................................ 12
2.2 Available for all Purposes: Shields ............................................... 13
2.2.1 Proto Shield ................................................................... 13
2.2.2 Motor Shield .................................................................. 13
(WKHUQHW6KLHOG. 14
1RWKLQJ+DSSHQVZLWKRXW3RZHUWKH3RZHU6XSSO\ ....................... 15
7KH0LFURFRQWUROOHU+HDUWRIWKH$UGXLQR ..................................... 15
2.5 The PC Connection: USB interface ............................................... 16
3 D evelopment Environment and Programming Basics ..................... 17
,QWHJUDWHG'HYHORSPHQW(QYLURQPHQW,'( ................................. 17
)RU/LQX[8VHUV$UGXLQR,'(8QGHU8EXQWX ................................. 23
6LPSOH%HJLQQLQJV7KH:DUQLQJ/LJKW ......................................... 24
3.4 General Structure of an Arduino Sketch ....................................... 24
%DVLF(OHPHQWVRIWKH&3URJUDPPLQJ/DQJXDJHIRU$UGXLQR ........... 27
3.6 Program Structures ................................................................... 29
$UGXLQR6SHFL¿F)XQFWLRQV ......................................................... 29
$UGXLQR3XQFWXDWLRQ6\QWD[(OHPHQWV. 30
'DWD6WRUDJH(OHPHQWV9DULDEOHV ............................................... 30
3.10 The Art of Math: Operators ........................................................ 31
3.11 To Be Clear: Logical Operators .................................................... 32
3.12 Unchanging Parameters: Constants ............................................. 35
3.13 Dealing with Related Data of the Same Type: Arays . 36
3.14 Program Control Structures ........................................................ 36
3.15 Controling Timing . 39
3.16 Mathematical Functions ............................................................. 40
3.17 Random numbers ..................................................................... 40
([WHQGLQJWKH2SWLRQV$GGLQJ/LEUDULHV ....................................... 41
4 Electronic Components and Low-Cost ‘Freeduinos’ ........................ 43
%UHDGERDUGV6LPSOHDQG(IHFWLYHZLWKRXW6ROGHULQJ . 43
4.2 Prototyping Boards: Durable Construction without Chemicals .......... 44
/RZ&RVWµ)UHHGXLQRV¶ . 45
$UGXLQRDQG,WV+HOSHUV%DVLF(OHFWURQLF&RPSRQHQWV ................... 46
4.4.1 USB Cable ..................................................................... 46
4.4.2 Resistors . 46
4.4.3 Capacitors . 47
4.4.4 Potentiometers . 47
/('V ............................................................................. 48
5*%/('V ...................................................................... 48
5
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4.4.7 Switches . 49
4.4.8 Silicon Diodes................................................................. 49
4.4.9 Transistors . 49
5 Helo World . 51
5.1 Cut to the Chaser ..................................................................... 51
,W*HWV%ULJKWHU&RQWUROOLQJ3RZHU/('V ...................................... 53
5.3 POVino: Persistence-of-Vision Display .......................................... 54
6 Displays and Display Techniques ................................................... 59
6.1 Bar Graph Display: The Classic for Measurement Applications ......... 59
6.2 Simple and Cheap: 7-Segment Displays . 59
'LJLW6HJPHQW'LVSOD\V$.H\&RPSRQHQWIRU,QVWUXPHQWDWLRQ 62
0LQL0RQLWRUIRU6LJQVDQG*UDSKLFV7KH/(''RW0DWUL[ . 67
6.5 Dot Matrix Display as a Two-Digit Digital Display ........................... 70
0LFUR/HDUQVWR:ULWH$OSKDQXPHULF'LVSOD\ ................................ 72
6.7 The LCD .................................................................................. 76
7 Measurement and Sensors ............................................................. 81
)OH[LEOHDQG(DV\WR5HDG$Q/('9ROWPHWHU . 81
9ROW$PPHWHU3UHFLVH,QVWUXPHQWIRUWKH+REE\LVW¶V/DE ............. 83
.LORRKPPHWHUIRU6SHFL¿F$SSOLFDWLRQV . 87
1R0RUH)DXOW\(OHFWURO\WLF&DSDFLWRU:RHV7KHµ(OFDGXLQR¶7HVWHU .. 89
µ3LFRIDUDGXLQR¶0HDVXULQJ6PDOOHU&DSDFLWDQFHV ........................... 91
µ7UDQVLVWLQR¶7UDQVLVWRU7HVWHU . 93
7.7 A Simple NTC Thermometer ....................................................... 95
+RWRU&ROG"7HPSHUDWXUH0HDVXUHPHQW8VLQJWKH$' ...... 98
7.9 Remote Thermometer . 99
µ7KHUPRGXLQR¶3UHFLVLRQ7KHUPRPHWHUZLWK6HJPHQW'LVSOD\ ...... 100
:KHQ$UH:H0RVW&RPIRUWDEOH"±7KH+\JURPHWHU ...................... 105
µ%DWGXLQR¶&DSDFLW\0HDVXUHPHQWIRU5HFKDUJHDEOH%DWHULHV . 107
2SWLFDO6HQVRUV,PSRUWDQWIRU0RUHWKDQ-XVW3KRWRJUDSK\ . 112
5HÀH[/LJKWIRU*HRFDFKLQJ ........................................................ 113
7.15 For Professional Photographers: A Digital Light Meter . 115
+RPHµ5DGDU6WDWLRQ¶'LVWDQFH0HDVXUHPHQW8VLQJ8OWUDVRXQG. 117
8 Timers, Clocks and Interrupts . 123
8.1 Morning and Night Fun: Grand Prix Toothbrush Timer .................... 123
3UDFWLFDODQG$FFXUDWH'LJLWDO&ORFNZLWK/(''LVSOD\ . 130
:KR¶V)DVWHU"$5HDFWLRQ7LPHU .................................................. 135
µ7LPHULQR¶8QLYHUVDO7LPHUZLWKD6HJPHQW'LVSOD\ . 138
3OXJLQ7LPHUWR0DNH/LIH(DVLHU ................................................ 141
8.6 Atomic Precision: The DCF77 Radio Clock ..................................... 142
2XWSXWRI7LPHDQG'DWHWRWKH6HULDO,QWHUIDFH ............................ 145
8.8 Stand-Alone DCF77 Clock with LCD Display .................................. 146
9 Interfaces . 149
8QLYHUVDODQG6LPSOH7KH,ð&,QWHUIDFH ...................................... 149
:KHQ:H5XQ2XWRI3LQV3RUW([SDQVLRQ . 152
+H[DGHFLPDO'HEXJJHU'LVSOD\8VLQJD'LJLW6HJPHQW'LVSOD\ . 155
/&'&RQWUROYLD,ð&8VLQJWKH3&) . 158
9.6 This Time, Fully Digital: The LM75 Thermometer ........................... 160
9.7 Power-Saving: Real-Time Clock with Date Display ......................... 163
6
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$IWHU,QFOXGLQJ7KH,5UHPRWH:LUHOHVV3UDFWLFDO4XLFN7KH,5,QWHUIDFH 167
µ/DPSLQR¶$Q,5&RQWUROOHG5*%/DPS ........................................ 171
7LPHO\/X[XU\$Q,5&RQWUROOHG'LJLWDO&ORFN ............................... 174
2SWLPDOIRU0LFURFRQWUROOHUV7KH36,QWHUIDFH ........................... 178
.H\ERDUGDQG0RXVHDV8QLYHUVDO,QSXW'HYLFHV ........................... 178
9.13 A Complete Microcomputer with LCD Monitor and Keyboard . 181
10 Sounds and Synthesizer . 185
10.1 Simple Tones . 185
7UDQVGXFHUVDQG$PSOL¿HUV . 187
)DVW3:00DNHV,W+DSSHQ1RW-XVWWRQHV%XW6RXQG:DYHV ........ 188
7KHUHPLQ7KH&RQWDFWOHVV0XVLFDO,QVWUXPHQW ............................. 195
10.5 Audio Processing. 197
9&2$7XQDEOH6LQH:DYH6RXUFH .................................... 198
10.5.2 Digital Signal Processing .................................................. 200
10.6 Sound Cloud: A Digital Synthesizer .............................................. 203
11 Digital Control Techniques ............................................................. 207
11.1 Control Types ........................................................................... 208
11.1.1 P Controler . 208
,&RQWUROOHU .................................................................... 209
3,&RQWUROOHU .................................................................. 209
11.1.4 PD Controller ................................................................. 209
3,'&RQWUROOHU ................................................................ 210
2SWLPXP:RUNVWDWLRQ/LJKWLQJ'LJLWDO,OOXPLQDWLRQ&RQWURO ............. 210
11.3 A Classic of Control Theory: The Gravity Compensator ................... 214
12 Physical Computing ....................................................................... 221
6HUYRV&RQWUROWKH:RUOG ........................................................... 221
µ3KRWLQR¶'&DPHUD6ZLYHO . 225
µ&UDQLQR¶0RXVH&RQWUROOHG&UDQH ..............................................
13 Processing . 231
13.1 Arduino and Processing: A Formidable Team ................................. 232
,QWHUDFWLRQZLWK3URFHVVLQJ'DWD/RJJLQJ7UHQG*UDSKVHWF ........ 233
14 The ‘Living Room Box’: Our Modular Concluding Project ................ 241
14.1 Always Useful: A Clock ............................................................... 242
&RQWUROIURP$IDU7KH,5,QWHUIDFH .............................................. 243
9&RQWUROIRU+L)LV\VWHPV7HOHYLVLRQV/DPSVHWF. 243
7LPHUVDQG6HQVRUVDVWKH%DVLVIRU+RPH$XWRPDWLRQ ................... 243
,QGRRUDQG2XWGRRU7KHUPRPHWHUV .............................................. 244
1R0RUH'U\$LU$+\JURPHWHU ................................................... 244
7KH+DUGZDUH ............................................................................ 244
Bibliography ......................................................................................... 249
Listings ................................................................................................ 251
List of Figures ...................................................................................... 253
List of Tables ........................................................................................ 257
Index ................................................................................................... 259
7
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1
Introduction
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ERDUGZKLFKKDVVLJQL¿FDQWO\HDVHGHQWU\LQWRWKHPLFURFRQWUROOHUKDUGZDUHDUHQD7\SL-
FDOEHJLQQHUSUREOHPVVXFKDVEDGSRZHUVXSSOLHVSUREOHPVZLWKVHWWLQJWKHFRQ¿JXUD-
WLRQSDUDPHWHUVIXVHELWVDQGFU\VWDOVWKDWZRQ¶WRVFLOODWHGXHWREDGORDGFDSDFLWDQFHV
DUHDOOIRUHLJQWRWKH$UGXLQRZRUOG7KHERDUGLVVLPSO\FRQQHFWHGWRD3&¶V86%SRUW
DQGRIIZHJR3HRSOH\RXQJDQGROGZKR¶YHQHYHUEHHQLQYROYHGLQHOHFWURQLFVZRQ¶W
KDYHDQ\GLI¿FXOW\
The second success factor is the associated programming interface, which is provided as
free-of-charge open source software. The second success factor is the associated pro-
JUDPPLQJLQWHUIDFHZKLFKLVSURYLGHGDVIUHHRIFKDUJHRSHQVRXUFHVRIWZDUH,QDGGL-
tion, installation is quick and easy, so the environment is usable immediately. Simple in-
troductory examples encourage rapid progress. The selection of complicated parameters
LVQRWUHTXLUHGDQGWKH¿UVWH[DPSOHSURJUDPVPD\EHRSHQHGDQGUXQZLWKLQPLQXWHV
Furthermore, the Arduino is backed up with a wealth of software libraries, and the num-
EHURIZKLFKJURZVGDLO\RIWHQSUHVHQWLQJEHJLQQHUVZLWKWKHLU¿UVWSUREOHPDIWHUWKH
introduction of simple examples, the way forward is not clear. This is often due to the
lack of detailed descriptions and explanations. The number of projects on the internet,
which are explained to a greater or lesser extent, is more likely to cause confusion. Be-
cause these applications are designed by a number of different people, each with their
own goals in mind, there is no common thread connecting them.
7KDW¶VZKHUH WKLV ERRN FRPHV LQ 3URMHFWV DUH LQWURGXFHG V\VWHPDWLFDOO\ HDFK LQWUR-
ducing a different theme. A practical hands-on approach is employed alongside the
necessary theoretical foundations and, in a similar vein, important concepts such as A/D
conversion, timers and interrupts are presented using practical projects. There are run-
ning lights, fully-functional voltmeters, precise digital thermometers, clocks of all kinds,
reaction timers and a mouse-controlled robot crane. Along the way, the reader will gain
an understanding of the associated controller techniques and pick them up fully — in the
truest sense of the word.
The practical projects presented herein will not be relegated to the status of mere ‘lab-
RUDWRU\SURWRW\SHV¶%\PHDQVRIDSSURSULDWHKLQWVDQGQRWHVRWKHUSUDFWLFDOGHYLFHV
will arise, which may be used for home, hobby and work. The projects are always imple-
PHQWHGXVLQJHDV\WR¿QGDQGLQH[SHQVLYHFRPSRQHQWV
,Q WKH¿QDOFKDSWHUDQ$UGXLQREDVHG µ/LYLQJ5RRP%R[¶ LVSUHVHQWHG ,W LVGHVLJQHG
modularly and may be adapted to individual requirements. The knowledge gleaned
throughout the book is used practically to produce a very useful, yet unusual, device.
9
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1.1 The Arduino Project
The ArduinoFRQFHSWFDPHWREHLQDWWKH,QVWLWXWHIRU,QWHUDFWLYH'HVLJQLQ,YUHD
,WDO\ 7KH VHDUFK IRU D ORZFRVWPLFURFRQWUROOHU V\VWHP IRU GHVLJQ VWXGHQWV OHG WR D
handy printed circuit board that contained all of the necessary electronic building blocks.
The main objective was the development of an inexpensive microcontroller board that
could be utilized quickly and simply by art and design students who had no previous
knowledge of programming or electronics.
7KH¿UVWYHUVLRQRIWKH$UGXLQRKDUGZDUHFRQVLVWHGRIDNLWWKDWFRXOGEHVROGHUHGWR-
gether easily, and it sold out quickly. Newer versions followed in rapid succession. De-
signers and artists from other regions took up the idea and the Arduino principle spread,
¿UVWLQ,WDO\WKHQLQWR(XURSHDQGHYHQWXDOO\WRWKHUHVWRIWKHZRUOG
,QWHUHVWJUHZUDSLGO\LQDSSOLFDWLRQDUHDVRXWVLGHRIDUWDFDGHPLHVDQGGHVLJQVFKRROV
The concept of a simple and low-cost hardware platform with a freely available, easy-to-
learn programming language was quickly embraced by hobbyists. Finally, schools and
XQLYHUVLWLHVLQWKHVFLHQWL¿FDQGWHFKQLFDO¿HOGVUHFRJQL]HGWKHHQRUPRXVSRWHQWLDORIWKH
$UGXLQRLGHD1HZKDUGZDUHYHUVLRQVDVZHOODVSOXJLQH[SDQVLRQERDUGVRUµVKLHOGV¶
DURVHDQG$UGXLQRDSSOLFDWLRQDUHDVZHUHOLPLWHGRQO\E\XVHUV¶LPDJLQDWLRQV
0HDQZKLOHWKHQXPEHURI$UGXLQRVVKLSSHGKDVH[FHHGHGWKHPDUNE\IDU,I
',<YHUVLRQVDQGFORQHVDUHFRQVLGHUHGDVZHOOWKHDFWXDO¿JXUHPD\H[FHHGPLOOLRQ
,WLVWKHUHIRUHQRH[DJJHUDWLRQWRFODLPWKDWWKH$UGXLQRPLFURFRQWUROOHUERDUGLVWKH
most successful of all time.
1.2 Book Structure and Target Audience
7KLVERRNLVDLPHGDWWKRVHZKR¶YHDOUHDG\KDGVRPHEDVLFH[SHULHQFHLQWKHHOHFWURQ-
LFV¿HOG7KHW\SLFDOKLJKVFKRROOHVVRQVRQFLUFXLWV2KP¶VODZHWFDUHIXOO\VXI¿FLHQW
,Q&KDSWHUWKHEDVLFIXQFWLRQVDQGFKDUDFWHULVWLFVRIWKHPDMRUFRPSRQHQWVDUHH[-
SODLQHG,QGXHFRXUVHPRUHHODERUDWHSURMHFWVDUHGLVFXVVHGVRWKDWHYHQVWXGHQWV
and teachers who come with some pre-existing technical knowledge will encounter new
challenges.
7KHSURMHFWVDUHJURXSHGLQWRLQGLYLGXDOWKHPHV+RZHYHUFDUHZDVWDNHQWRSODFHWKH
less technically challenging material at the beginning of the book. For this reason, be-
JLQQHUVZLOO¿QGLWKHOSIXOWRJRWKURXJKWKHERRN¶VFKDSWHUVLQRUGHUHYHQLIQRWHYHU\
single project is constructed.
10
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Figure 4.1:
Breadboard
4.2 Prototyping Boards: Durable Construction without Chemicals
,IDSDUWLFXODUFLUFXLWKDVEHHQFRPSOHWHO\WHVWHGDQGLVZRUNLQJSURSHUO\LWPD\WKHQ
be built on prototyping board. There are different versions available. The most common
types are stripboard and perfboard. The former usually results in a circuit with fewer
solder connections, although many circuit traces are likely to require severing. On the
other hand, boards with individual solder pads require all electrical connections have to
be individually created, so no manual severing is required on the board itself, but many
more solder connections are required.
Figure 4.2:
Stripboard
Figure 4.3:
A Perfboard has Individual Pads
44
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+RZHYHUWKHVHDUHUHODWLYHO\XQFRPPRQDQGWKHUHIRUHH[SHQVLYHVRWKH\ZRQ¶WEHGH
scribed any further here. Another option for displaying alphabetical characters, the dot
matrix display, is covered in a later section.
Figure 6.1:
Typical Pin Layout on a Single 7-Segment Display
The wiring of a common-cathode 7-segment display is shown in Figure 6.2. Since a
numeric digit requires several segments to be lit simultaneously, one might expect an in-
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Figure 6.2:
Control of a Single 7-Segment
Display.
60
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The problems associated with NTCs, such as the nonlinear relationship between tem-
perature and resistance, as well as the requirement of a second resistor to make up a
voltage divider, which introduces additional inaccuracy, etc., all fall away.
7KH/0LVDGYDQWDJHRXVHYHQZKHQFRPSDUHGZLWKWKHDQDORJ$':KHQDQ
alog transmission of temperature data takes place over a long cable, errors are eas-
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electromagnetic radiation, such as from mobile phones and electric motors, may cause
unacceptable interference. Lastly, contact stresses at plugs and connections may lead to
HUURQHRXVUHDGLQJV)RUVKRUWOLQHVWKHVHLQÀXHQFHVDUHXVXDOO\QHJOLJLEOHEXWDOUHDG\
for lines in excess of 1 m, problems start occurring in practice. Digital transmission via
,ð&RQWKHRWKHUKDQGLVVLJQL¿FDQWO\PRUHUHVLOLHQW
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and its corresponding pin. For larger applications, this can quickly lead to a pin short-
3
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FRQQHFWHGWRWKH,ð&EXVVLPXOWDQHRXVO\
Figure 9.11:
LM75 for Local
Measurements
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,Qsetup(), Wire and Lcd are initialized. Then follows the printing of a template for
the output of temperature values to the LCD. The main loop begins by setting the most
VLJQL¿FDQWDQGOHDVWVLJQL¿FDQWE\WHVIRUHDFKFRQQHFWHGVHQVRU7KHWZRVHQVRUVDUH
then read, one after the other. Conversion of the byte values takes place as per the
/0¶VGDWDVKHHW)LQDOO\WKHWHPSHUDWXUHUHDGLQJLVRXWSXWWRWKH/&'
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click = Mouse.read();
mouseX = Mouse.read();
mouseY = Mouse.read();
// send data
Serial.print(“X=”);
Serial.print(mouseX, DEC);
Serial.print(“\tY=”);
Serial.print(mouseY, DEC);
switch (click) {
case
Serial.print(“\t left click”);
break;
case 10:
Serial.print(“\t right click”);
break;
case 11:
Serial.print(“\t both click”);
break;
}
Serial.println();
delay(20);
}
void mouseInit() {
Mouse.write(0xff); // reset
Mouse.read(); // con¿rm byte times
Mouse.read();
Mouse.read();
Mouse.write(0xf0); // remote mode
Mouse.read(); // con¿rm
delayMicroseconds(100);
}
,QRXUODWHUFKDSWHURQSK\VLFDOFRPSXWLQJSURMHFWVDUHSUHVHQWHGLQZKLFKYDULRXVGH-
vices are controlled using the mouse.
9.13 A Complete Microcomputer with LCD Monitor and Keyboard
Connect a keyboard and a mouse to the Arduino, and you have yourself a complete
microcomputer. Together with an LCD display, it forms a system with performance com-
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181
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