maXbox_Arduino_Pascal_Magazine

Issue Nr 6 2015 BLAISE PASCAL MAGAZINE70
MAXBOX STARTER 18 PAGE 1/8
START WITH ARDUINO PROGRAMMING V3.1
Arduino hardware is programmed using a Wiring-
based language (syntax and libraries), similar to C++
and Object Pascal with some simplifications and
modifications, and a Processing-based integrated
development environment like Delphi or Lazarus
with Free Pascal.
Current versions can be purchased preassembled;
hardware design information is available for
those who would like to assemble an Arduino by
hand. Additionally, variations of the Italian-
made Arduino — with varying levels of
compatibility — have been released by third
parties; some of them are programmed using the
Arduino software or the sketch firmware.
The Arduino is what is known as a Physical or
Embedded Computing platform, which means
that it is an interactive system that through the
use of hardware, firmware and software can
interact with its environment.
This lesson will introduce you to Arduino and the
Serial communication (see Tutorial 15). We will
now dive into the world of serial communications
and control our lamp from a browser to a web
server by sending commands from the PC to the
Arduino using a serial monitor with interface.
In our case we explain one example of a HTTP
server which is an intermediate to the COM serial
communication with the AVR based micro
controller on Arduino.
Another Controller is the Delphi Controller. A
Delphi Controller and the DelphiDevBoard were
designed to help students, Pascal programmers
and electronic engineers understand how to
program micro controllers and embedded
systems especially in programming these devices
and targets (see links at the end).
This is achieved by providing hardware (either
pre-assembled or as a DIY kit of components), using
course material, templates, and a Pascal
compatible cross-compiler and using of a
standard IDE for development and debugging
(Delphi, maXbox, Lazarus or Free Pascal).
Let’s begin with HTTP (Hypertext Transfer
Protocol) and TCP. TCP/IP stands for
Transmission Control Protocol and Internet
Protocol. TCP/IP can mean many things, but in
most cases, it refers to the network protocol itself.
Each computer on a TCP/IP network has a
unique address associated with it, the so called
IP-Address. Some computers may have more
than one address associated with them. An IP
address is a 32-bit number and is usually
represented in a dot notation, e.g. 192.168.0.1.
Each section represents one byte of the 32-bit
address. In maXbox a connection with HTTP
represents an object.
In our case we will operate with the local host. It
is common for computers to refer to themselves
with the name local host and the IP number
127.0.0.1.
PHYSICAL COMPUTING WITH RGB LED
Today we enter a topic in programming called
embedded computing with the internet; we code a
RGB LED light on a Arduino board with a breadboard
on which we switch off or on the light by a browser
on an android device with our own web server and
their COM protocols too. Hope you did already work
with the Starter 1 till 17 (especially the 17) at:
http://sourceforge.net/apps/mediawiki/maxbox/
maXbox
maXbox
GET THE CODE
As you already know the tool is split up into the
toolbar across the top, the editor or code part in
the centre and the output window at the bottom.
Change that in the menu /view at our own style.
In maXbox you will start the web server as a
script, so the web server IS the script that starts
the Indy objects, configuration and a browser too
(on board: Options/Add_ons/Easy_Browser/.
Before this starter code will work you will need
to download maXbox from the website. It can be
down-loaded from
http://www.softwareschule.ch/maxbox.ht
m (you’ll find the download maxbox3.zip on our
website in your personal download area). Once the
download has finished, unzip the file, making
sure that you preserve the folder structure as it is.
If you double-click maxbox3.exe the box opens a
default demo program.

Issue Nr 6 2015 BLAISE PASCAL MAGAZINE 71
program ;Motion_HTTPServer_Arduino42_RGB_LED_Light
• This example requires two objects from the
classes: TIdCustomHTTPServer and
TComPort so the second one is to connect and
transport with the COM ports to Arduino
(see below). TComPort by Dejan Crnila are
Delphi/C++ Builder serial communications
components. (It will be in your download area after
publishing this issue).
It is generally easy to use for basic serial
communications purposes, alternative to the
TurboPower ASYNCPro.
It includes 5 components: TComPort,
TComDataPacket, TComComboBox,
TComRadioGroup and TComLed.
So the object HTTPServer has some methods and
properties like Active you can find in the
TIdCustomHTTPServer.pas unit or
IdHTTPServer library. A library is a collection of
code or classes, which you can include in your
program. Once a unit is tested it’s stable to use.
START WITH ARDUINO PROGRAMMING V3.1 maXbox
maXbox
Test it with F9 / F2 or press Compile and you can
open now the script example:
443_webserver_arduino_rgb_light5.txt
If you want to get the whole package with Arduino
sketches too, then try the zip-file:
http://www.softwareschule.ch/download/
ardpac.zip
Now let’s take a look at the code of this project.
Our first line is
Figure 1:
The GUI of the Win App
Indy is designed to provide a very high level of
abstraction. Much more stuff or intricacies and
details of the TCP/IP stack are hidden from the
Indy programmer. A typical Indy client session
looks like this:
with do beginIndyClient
:= ;Host 'zip.pbe3.com' // Host to call
:= ;Port 6000 // Port to call the server on
;Connect // get something to do with it
end;
With these tools you can build serial
communication apps easier and faster than ever.
First we start with the web server and second we
explain the COM port. After creating the object
we use first methods to configure our server
calling Port and IP. The object makes a bind
connection with the Active method by passing a
web server configuration.
HTTPServer TIdCustomHTTPServer Create self:= . ( );

Indy is different than other so called winsock
components you may be familiar with. If you've
worked with other components, the best approach
for you may be to forget how they work. Nearly
all other components use non-blocking
(asynchronous) calls and act asynchronously.
They require you to respond to events, set up state
machines, and often perform wait loops.
• In fact there are 2 programming models used in
TCP/IP applications. Non Blocking means that
the application will not be blocked when the
application socket read/write data. This is
efficient, because your application don't have to
wait for a connection. Unfortunately, it is
complicated to develop.
Figure 2: The Use Case
maXbox
So let’s get back to our HTTP Create in line 123.
In line 131 and 132 you see port and IP address
configuration of a Const, instead of IP you can
also set a host name as a parameter.
• Host names are "human-readable" names for
IP addresses.
An example host name is max.kleiner.com, the
www is just a convention and not necessary.
Every host name has an equivalent IP address,
e.g. www.hower.org = 207.65.96.71.
Log Result
<<extend>>
Win Form
Control LED
Matrix
HTTP Service
Com Interface
Arduino Terminal Monitor
System Micro Controller Boundary
Start COM Interface
Start HTTP Server
Open Browser
Indy HTTP Server
Arduino Board RGB LED
<<include>>
Actor HEX in the BOX
Browser Web Form
with doHTTPServer
begin
If then ;Active Free
If not thenActive
begin
. ;Bindings Clear
. ;bindings Add
bindings items Port APORT. [ ]. := ;0
bindings items IP IPADDR. [ ]. := ;0
//'127.0.0.1'; 192.168.1.53'
Active true:= ;
onCommandGet HTTPServerGet:= @ ;
PrintF( ,'Listening HTTP on %s:%d.'
[ [ ]. , [ ]. ]);Bindings IP Bindings Port0 0
;end

3: A few gadgets for Arduino
The full target of the request
message is given by the URL
property. Usually, this is a URL that
can be broken down into the
protocol (HTTP), Host (server system), script
name (server application), path info
(location on the host), and a query.
• So far we have learned little
about HTTP and host names.
Now it’s time to run our program
at first with F9 (if you haven’t done yet) and
learn something about GET and HTML.
The program (server) generates a standard
HTML output or other formats (depending on
the MIME type) after downloading with GET
or HEAD.
So our command to shine on a LED is ../LED and
to switch off is ../DEL (127.0.0.1:8000/LED).
Those are GET commands send with the browser,
or /R for Red or /G for Green.
The first line identifies the request as a GET.
A GET request message asks the Web server
application to return the content associated with
the URI that follows the word GET.
The following shows the magic behind in the
method HTTPServerGet():
One word concerning the thread: In the internal
architecture there are 2 threads categories.
First is a listener thread that “listens” and waits
for a connection. So we don't have to worry about
threads, the built in thread TIdPeerThread will be
served by Indy through a parameter:
if ( ) = ( )uppercase localcom uppercase '/LED'
then
begin
. ( )cPort WriteStr '1'
( + );writeln localcom ': LED on'
. := ( );RespInfo ContentText getHTMLContentString 'LED is: ON'
end
else
if then begin( ) = ( )uppercase localcom uppercase '/DEL'
. ( );cPort WriteStr 'A'
( + );writeln localcom ': LED off'
. := ( )RespInfo ContentText getHTMLContentString 'LED is: OFF'
end;
webswitch webswitch:= ;NOT
if thenwebswitch
begin
cPort WriteStr. ( )'1' //goes to Arduino
RespInfo ContentText. :=
getHTMLContentString( );'LED is: ON Switch'
end
else
begin
cPort WriteStr. ( );'A'
RespInfo ContentText. :=
getHTMLContentString( )'LED is: OFF Switch'
end
end
maXbox
( : ;procedure HTTPServerGet aThr TIdPeerThread
reqInf TIdHTTPRequestInfo respInf TIdHTTPResponseInfo: ; : );
HTTP request messages contain many headers
that describe information about the client, the
target of the request, the way the request should
be handled, and any content sent with the request.
Each header is identified by a name, such as
"Host" followed by a string value. It then does a
request.
• You can also switch with F5 in a browser to
switch LED on and off:

One of a practical way to learn much more
about actually writing HTML is to get in
maXbox editor and load or open a web-file
with the extension html. Or you copy the
output and paste it in a new maXbox instance.
Then you click on the context menu and
change to HTML Syntax!
In this mode the PC is a master and executes
the control algorithm while the Arduino or Delphi
Controller acts as an interface slave and follows
commands coming from the PC or browser
through its RS232 port. Each RGB field in these
records reflects a state of the sensors and
actuators of the LED in those sense only actors as
LED light are in use.
A running Arduino (M485A) monitor server will
accept commands on input through a RS232 port:
When the browser starts from script the server is
ready for commands to pass chars to the serial
communication. When a the server application
finishes with our client request, it lights the LED
and constructs a page of HTML code or other
MIME content, and passes the result back (via the
server in TIdHTTPResponseInfo ) to the client
for display.
Figur 4: The Browser controls
Have you tried the program, it’s also possible to
test the server without Arduino or a browser.
When you run this code from the script
102_pas_http_download.txt you will see a
content (first 10 lines) of the site in HTML format
with the help of the method memo2.lines.add:
begin
:= . ( )idHTTP TIdHTTP Create NIL
try
. . := . ( )memo2 lines text idHTTP Get2 'http://127.0.0.1'
:=for to doi 1 10
. . ( ( )+ + . [ ])memo2 lines add IntToStr i memo2 lines i' :'
finally
.idHTTP Free
end
• The Object TIdHTTP is a dynamically
allocated block of memory whose structure
is determined by its class type. With the
method Get1 you can download files.
maXbox
if ( == )val '1' {
digitalWrite(ledPin11,HIGH); }
( == )else if val 'A' {
digitalWrite(ledPin1,LOW);
}
( == )if val '2' {
digitalWrite(ledPin2,HIGH); }
writeln localcom( + );': LED on'
. := ( );RespInfo ContentText getHTMLContentString 'LED is: ON'
begin
myURL:=
'http://www.softwareschule.ch/download/maxbox_examples.zip
zipStream TFileStream Create fmCreat:= . ( ,'myexamples2.zip'
idHTTP TIdHTTP Create:= . ( )NIL
try
idHTTP Get1 myURL zipStream. ( , )
Of course a lot of lines to get a file from the web try
it shorter with the magic function wGet():
wGet( ,'http://www.softwareschule.ch/download/maxbox_starter17.pdf'
'mytestpdf.pdf');
It downloads the entire file into memory if the
data is compressed (Indy 9 does not support
streaming decompression for HTTP yet). Next we
come closer to the main event of our web server in
line 40, it’s the event onCommandGet with the
corresponding event handler method
@HTTPServerGet() and one object of
TidPeerThread.
You can use them as server as the way to serve
files of many kinds!

SERIAL LINE
Please read more about serial coding in Tutor 15!
The serial communications line is simply a way
for the Arduino to communicate with the outside
world, in this case to and from the PC (via USB)
and the Arduino IDE’s Serial Monitor or from
the uploaded code to I/O Board back.
We just create and configure our COM settings
(depends in which COM port a USB hub works).
maXbox
The Arduino can be used to develop stand-alone
interactive objects or it can be connected to a
computer to retrieve or send data to the Arduino
and then act on that data (e.g. send sensor data
out to the web or write data on a control LED).
Now we change to the Arduino editor to explain
how he handles our commands (chars).
Serial.begin tells Arduino to start serial and the
number within the parenthesis, in this case 9600,
sets the baud rate (chars per second) that the
serial line will communicate at.
5: maXuino Together Settings
procedure ( : );TForm1_FormCreateCom Sender TObject
begin
:= . ( );cPort TComPort Create self
with do begincPort
:= ;BaudRate br9600
:= ;Port COMPORT //'COM3';
. := ;Parity Bits prNone
:= ;StopBits sbOneStopBit
:= ;DataBits dbEight
;end
In the main loop we have an “if statement”. The
condition it is checking the value in (Serial.read).
The Serial.available command checks to see if any
characters have been sent down the serial line. If
any characters have been received then the
condition is met and the code within the “if
statements” code block is now executed, you see if
‘1’ then ON and if ‘A’ then OFF.
The condition of checking is simply a char it’s up
to you to code a protocol of your own .
void ()loop {
// read on the serial portval = Serial.read();
if val ! -1)( = {
val 1'if ( ==' ){
digitalWrite ledPin1 HIGH( , );
}
( == )else if val 'A' {
digitalWrite ledPin1 LOW( , );
}
Serial print Data entered. (" : ");
int val = ;0
// variable to store data from the serial port
int ledPin11 = ;11
// LED connected to digital pin 11 or the inbuilt 13!
void setup() {
pinMode(ledPin11,OUTPUT);
// declare a LED's pin as output mode
// connect to serial porterial.begin(9600);
..}

and this is our way of sending data back from
the Arduino to the PC. In this case the print
command sends whatever is within the
parenthesis to the PC, via the USB cable, where
we can read it in the monitor window or in
maXbox.
BREAD BOARD FLOW
At last but not least some words about
breadboards and electronics. A breadboard (or
protoboard) is usually a construction base for
prototyping devices of electronics. The term
"breadboard" is commonly used to refer to a
solder less breadboard (plug board).
With the breadboard you prepared above or
below, add three wires for power to RGB light and
one for ground GND for your AVR controller.
Place 3 resistors and LED as shown. Make sure the
longest leg of the LED is to GND, connected to the
minus. The resistors don’t have a direction, so it
doesn’t matter which way it goes in.
6: Breadboard Settings
If you're using a standard breadboard, you'll
need to use wires to reach the Arduino. Run 3
wires (red, green and blue) to the pin sockets on
the Arduino. Run the other wire (black) to one of
the GND sockets on the Arduino. The colours
aren't essential but they will help you remember
what the wires are connected to and black is a
convention for ground GND!
Once the connection to a client socket is
completed, the server connection is
indistinguishable from a client connection. Both
end points have the same capabilities and
receive the same types of events. Only the
listening connector is fundamentally different,
as it has only a single endpoint.
Sockets provide an interface between your
network server or client application and a
networking software. You must provide an
interface between your application and clients
that use it.
maXbox
Figure 7: PWM Signal measure in Oscilloscope
Sockets let your network application
communicate with other systems over the
network. Each socket can be viewed as an
endpoint in a network connection. It has an
address that specifies:
• The system on which it is running.
• The types of interfaces it understands.
• The port it is using for the connection.
A full description of a socket connection
includes the addresses of the sockets on
both ends of the connection. You can
describe the address of each socket
endpoint by supplying both the IP address
or host and the port number.

Issue Nr 6 2015 BLAISE PASCAL MAGAZINE
In the next line we just start a browser to test our
server in a so called frame work flow.
Some notes at last about firewalls or proxy-servers.
It depends on your network infrastructure to get a
file or not, maybe you can’t download content
cause of security reasons and it stops with
Socket-Error # 10060 and a time out error.
Furthermore, it also depends on the firewall in use
at both ends. If it's automatic and recognises data
that needs a response automatically it will work.
It needs an administrator to open ports etc. you’re
stuffed or configured.
Hope you did learn in this tutorial the theme of
Arduino with a web server. The Arduino is an
amazing device and will enable you to make
anything from interactive works of art to robots.
With a little enthusiasm to learn how to program
the Arduino and make it interact with other
components a well as a bit of imagination,
you can build anything you want.
The Arduino can also be extended with the use
of Shields which circuit boards are containing
other devices (e.g. GPS receivers, LED Cubes,
LCD Displays, Sneakers, MIDI Synthesizers,
Ethernet connections, etc.) that you can simply
slot into the top of your Arduino to get extra
functionality.
The Arduino board is made of an Atmel AVR
microprocessor, a crystal or oscillator (basically a
crude clock that sends time pulses to the micro-
controller to enable it to operate at the correct what
type of Arduino you have, you may also
have a USB connector to enable it to be
connected to a PC or Linux to upload or
retrieve data. The board exposes the
micro-controllers I/O (Input/Output)
pins to enable you to connect those pins
to other circuits, buses or to sensors, etc.
Feedback please to: max@kleiner.com
Literature:
Kleiner et al., Patterns konkret, 2003,
Software & Support
maXbox 77
procedure ;letOpenBrowser
// TS_ShellExecuteCmd = (seCmdOpen,seCmdPrint,seCmdExplore);
begin
//ShellAPI.ShellExecute(Handle,PChar('open'),'http://127.0.0.1:80/',Nil,Nil,0);
S_ShellExecute IPADDR IntToStr APORT seCmdOpen( + + + ( )+ , , )'http:' ':' '/' ''
end;
Try to change the IP address in line 132 of
IP:= IPADDR with a DHCP or dynDNS address,
so you can reach Arduino from an Android, but also
change settings.
Links of maXbox, Web of Things, Arduino
and Indy:
http://www.softwareschule.ch/download/
webofthings2013.pdf
http://www.softwareschule.ch/
maxbox.htm
http://www.indyproject.org/
Sockets/index.EN.aspx
http://en.wikipedia.org/wiki/Arduino
http://fritzing.org/
http://sourceforge.net/projects/maxbox
http://sourceforge.net/projects/
delphiwebstart
http://www.blaisepascal.eu/index.php?
actie=./subscribers/
UK_Electronics_Department
http://www.blaisepascal.eu/subscribers/
vogelaar_elctronics_info_english.php
APPENDIX DELPHI CONTROLLER
http://www.blaisepascal.eu/index.php
?actie=./subscribers/UK_Electronics_Department
DELPHI SCHEMA

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