Steps to Setup the Netduino

Wiring the LCD Display–

Figure 6 - Tape the pins into place onto the LCD display

Figure 7 - Solder wires to the LCD display.

Hook up the cables as follows -

LCD Pin Number	Symbol	Netduino Pin	Description
1	VSS	GND	Ground
2	VDD	5V	Logic voltage
3	V0	10K Pot Leg 2	op voltage for LCD. Controls color/contrast
4	RS	D12	Register selector
5	R/W	GND	Low means write, so you can just ground it
6	E	D11	Chip enable
7	DB0	D9	Data Bit 0
8	DB1	D8	Data Bit 1
9	DB2	D7	Data Bit 2
10	DB3	D6	Data Bit 3
11	DB4	D5	Data Bit 4
12	DB5	D4	Data Bit 5
13	DB6	D3	Data Bit 6
14	DB7	D2	Data Bit 7
15	LED(+)	Resistor to 5V	Backlight LED Anode
16	LED(-)	Ground	Backlight LED Cathode

Figure 8 - Begin to Attach the Netduino to the Breadboard with Cables

Code

Classes created by Secret Labs for the Netduino –

Class	Namespace	Assembly
AnalogInput	SecretLabs.NETMF.Hardware	SecretLabs.NETMF.Hardware.dll
Pins	SecretLabs.NETMF.Hardware.Netduino-Plus	SecretLabs.NETMF.Hardware.Netduino-Plus.dll

Classes created by the author of Getting Started with the Internet of Things – Cuno Pfister

Class	Namespace	Assembly
Buffer	Gsiot.Server	Gsiot.Server.dll
CSharpRepresentation	Gsiot.Server	Gsiot.Server.dll
DigitalActuator	Gsiot.Server	Gsiot.Server.dll
Digital Sensor	Gsiot.Server	Gsiot.Server.dll
Http Server	Gsiot.Server	Gsiot.Server.dll
Manipulated Variable	Gsiot.Server	Gsiot.Server.dll
Measured Variable	Gsiot.Server	Gsiot.Server.dll
PachubeClient	Gsiot.PachubeClient	Gsiot.PachubeClient.dll
RequestHandler Context	Gsiot.Server	Gsiot.Server.dll

Gsiot.Server project

The Gsiot.Server project encapsulates some of the web server functionality needed to interpret and respond to web requests. The project as it comes from the book needs to be modified and re-compiled in order to handle and relay requests to the LCD.

File		Notes		Code
Representations.cs	Add this function to allow the handling of string variables in the put method.		public static bool TryDeserializeString(RequestHandlerContext context, out object content) { if (context.RequestContent != null) { content = context.RequestContent; return true; } content = null; return false; }

Other changes in the Server.cs file have been made to expose network settings assigned by the DHCP server in your router to the program that will be using this DLL. Please see the code.

public string DHCP { get; set; }

public string MAC { get; internal set; }

public string IPAddress { get; internal set; }

public string GWAddress { get; internal set; }

public string DNS1Address { get; internal set; }

public string BaseURI { get; internal set; }

Then further down in the code -

void NetworkConfiguration()

{

NetworkInterface[] nis =

NetworkInterface.GetAllNetworkInterfaces();

// we assume that a network interface is available

Contract.Assert(nis[0] != null);

var x = new char[17];

var i = 0;

byte[] a = nis[0].PhysicalAddress;

const string hex = "0123456789ABCDEF";

for (var j = 0; j != 6; j = j + 1)

{

x[i] = (char)(hex[(a[j] & 0xF0) >> 4]);

i = i + 1;

x[i] = (char)(hex[a[j] & 0x0F]);

i = i + 1;

if (i != 17)

{

x[i] = '-';

i = i + 1;

}

Debug.Print("DHCP enabled: " + nis[0].IsDhcpEnabled);

if (nis[0].IsDhcpEnabled) { DHCP = "true"; } else { DHCP = "false"; }

string mac = new string(x);

Debug.Print("MAC address: " + mac);

MAC = mac;

string localHost = nis[0].IPAddress;

Debug.Print("Device address: " + localHost);

IPAddress = localHost;

Debug.Print("Gateway address: " + nis[0].GatewayAddress);

GWAddress = nis[0].GatewayAddress;

if (nis[0].DnsAddresses.Length > 0)

{

Debug.Print("Primary DNS address: " + nis[0].DnsAddresses[0]);

DNS1Address = nis[0].DnsAddresses[0];

}

string uri = "http://";

if (RelayDomain != null)

{

uri = uri + RelayHost;

}

else

{

uri = uri + localHost;

}

if (Port != 80)

{

uri = uri + ":" + Port;

}

if (RelayDomain != null)

{

uri = uri + "/" + RelayDomain;

} serviceRoot = uri; Debug.Print("Base Uri: " + uri + "/"); BaseURI = serviceRoot;

}

After making these changes compile the Gsiot.Server in Release mode.

The newly compiled DLL Gsiot.Server.dll will require the be and the le directories whenever you include it in your project. The new project name is NetworkLCD -

NetworkLCD project

The NetworkLCD project handles 3 main functions:

- Listen for incoming web requests using a multithreaded instance of the Gsiot.Server.

- Initialize and write text to the LCD display.

- Initialize and blink the on-board LED at a given rate.

Figure 9 - Hello World! And the Blinking LED

Code from the Program.cs in the NetworkLCD program -

/* --Code from Program.cs in the NetworkLCD program--------------------

* SET UP LCD

* --------------------- */

var lcdThread = new Thread(lcd.Run);

lcdThread.Start();

print(bufferStr,"start LCD");

/* ---------------------

* SET UP LED

* --------------------- */

var blinkerThread = new Thread(blinker.Run);

blinkerThread.Start();

print(bufferStr, "start LED");

/* ---------------------

* Start Server

* --------------------- */

webServer.Open();

print(bufferStr,"Server " + webServer.BaseURI);

baseuri = webServer.BaseURI;

webServer.Run();

}

/* ---------------------

* put txt message in

* buffer for LCD thread

* to pick up and display

* --------------------- */

static void print(Buffer buffer, string msg) {

buffer.HandlePut(msg);

}

/* ---------------------

* return a "file" to the

* web client with instructions

* on which put methods to

* send us

* --------------------- */

static void HandleBlinkTargetHtml(RequestHandlerContext context) {

string requestUri = context.BuildRequestUri("/blinkingPeriod/target");

string requestUri2 = context.BuildRequestUri("/lcdMessage/target");

var script =

@"<html>

<head>

var r;

try {

r = new XMLHttpRequest();

} catch (e) {

r = new ActiveXObject('Microsoft.XMLHTTP');

}

function put (content) {

r.open('PUT', '" + baseuri + requestUri + @"');

r.setRequestHeader(""Content-Type"", ""text/plain"");

r.send(document.getElementById(""period"").value);

}

function putLCD (content) {

r.open('PUT', '" + requestUri2 + @"');

r.setRequestHeader(""Content-Type"", ""text/plain"");

r.send(document.getElementById(""msg"").value);

}

</script>

</head>

<body>

<p>

Blink Rate

</p><p>

Message

</p>

</body>

</html>";

context.SetResponse(script, "text/html");

}

/* ---------------------

* Continuously checks for

* new strings in the buffer

* to display

* --------------------- */

public class LCD {

public Buffer SourceBuffer { get; set; }

static GpioLcdTransferProvider lcdProvider = new GpioLcdTransferProvider(

Pins.GPIO_PIN_D12, // RS

Pins.GPIO_NONE, // RW

Pins.GPIO_PIN_D11, // enable

Pins.GPIO_PIN_D9, // d0

Pins.GPIO_PIN_D8, // d1

Pins.GPIO_PIN_D7, // d2

Pins.GPIO_PIN_D6, // d3

Pins.GPIO_PIN_D5, // d4

Pins.GPIO_PIN_D4, // d5

Pins.GPIO_PIN_D3, // d6

Pins.GPIO_PIN_D2); // d7

static Lcd lcd;

public void Run() {

// create the LCD interface

lcd = new Lcd(lcdProvider);

// set up the LCD's number of columns and rows:

lcd.Begin(16, 2);

// Print a message to the LCD.

print("init LCD");

var period = 500;

string msg = "";

while (true) {

Thread.Sleep(period / 2);

object setpoint = SourceBuffer.HandleGet();

if (setpoint != null) {

if (msg != (string)setpoint) {

msg = (string)setpoint;

Debug.Print(msg);

print(msg);

}

static void print(string msg) {

lcd.Clear();

lcd.Write(msg);

}

End of today's post.

Tuesday, February 28, 2012

Steps to Setting Up the Netduino

Steps to Setup the Netduino

Wiring the LCD Display–

Code

Gsiot.Server project

NetworkLCD project

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