ARM HOW-TO GUIDE Interfacing SPI- Ethernet with · PDF file25/12/2014 ·...

ARM HOW-TO GUIDE

Interfacing SPI-

Ethernet with LPC2148

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Contents at a Glance

ARM7 LPC2148 Slicker Board ........................................... 3

SPI (Serial Peripheral Interface) ........................................ 3

Ethernet .......................................................................... 4

The ENC28J60 Ethernet Controller ................................... 4

Interfacing SPI-Ethernet ................................................... 5

Interfacing SPI-Ethernet with LPC2148 ............................. 7

Pin Assignment with LPC2148 .......................................... 7

Circuit Diagram to Interface SPI-Ethernet with LPC2148 ... 8

Source Code .................................................................... 8

C Program to interface Ethernet with LPC2148 ................. 9

Testing the SPI-Ethernet with LPC2148 ........................... 16

General Information ...................................................... 17



ARM7 LPC2148 Slicker Board

The ARM7 LPC2148 Slicker board is specifically

designed to help students to master the required skills in

the area of embedded systems. The kit is designed in such

way that all the possible features of the microcontroller will

be easily used by the students. The kit supports in system

programming (ISP) which is done through serial port.

NXP’s ARM7 (LPC2148), ARM Slicker Kit is proposed to

smooth the progress of developing and debugging of

various designs encompassing of High speed 32-bit

Microcontrollers.

SPI (Serial Peripheral Interface)

Serial Peripheral Interface (SPI) is a synchronous serial

data protocol used by microcontrollers for communicating

with one or more peripheral devices quickly over short

distances. It can also be used for communication between

two microcontrollers.



Ethernet

Ethernet is the most widely-installed local area network

(LAN) technology. An Ethernet LAN typically uses coaxial

cable or special grades of twisted pair wires. Ethernet is also

used in wireless LANs. The most commonly installed

Ethernet systems are called 10BASE-T and provide

transmission speeds up to 10 Mbps. Devices are connected

to the cable and compete for access using a Carrier Sense

Multiple Access with Collision Detection (CSMA/CD)

protocol.

The ENC28J60 Ethernet Controller

Microchip’s ENC28J60 controller is a 28-pin, 10BASE-T

standalone Ethernet Controller, with on board MAC & PHY,

8 Kbytes of Buffer RAM and an SPI serial interface used as

an Ethernet network interface for any microcontroller

equipped with SPI interface. So the microcontroller can

then control remotely any hardware.



Interfacing SPI-Ethernet

Fig. 1 shows how to interface the SPI-Ethernet to

microcontroller. With an SPI connection there is always one

master device (usually a microcontroller) which controls the

peripheral devices. Typically there are three lines common

to all the devices,

Master In Slave Out (MISO) - The Slave line for

sending data to the master,

Master Out Slave In (MOSI) - The Master line for

sending data to the peripherals,

Serial Clock (SCK) - The clock pulses which

synchronize data transmission generated by the master,

and

Slave Select pin - the pin on each device that the

master can use to enable and disable specific devices. When

a device's Slave Select pin is low, it communicates with the

master. When it's high, it ignores the master.



This allows you to have multiple SPI devices sharing the

same MISO, MOSI, and CLK lines.

Fig. 1 Interfacing SPI-Ethernet to Microcontroller

The Ethernet buffer contains transmit and receive

memory used by the Ethernet controller. The entire buffer

is 8 Kbytes, divided into separate receive and transmit

buffer spaces. The sizes and locations of transmit and

receive memory are fully programmable by the host

controller using the SPI interface. Any space within the 8-

Kbyte memory, which is not programmed as part of the

receive FIFO buffer, is considered to be the transmit buffer.



Interfacing SPI-Ethernet with LPC2148

In SPI, the clock signal is controlled by the master

device LPC2148 Slicker Board. All data is clocked in and out

using this pin. These lines need to be connected to the

relevant pins on the LPC2148 Slicker Board. Any unused GIO

pin can be used for CS, instead pull this pin high. The

ENC28J60 requires a single per packet control byte to

precede the packet for transmission to Microcontroller. An

IP address is used to access the Ethernet control. The

ENC28J60 SPI connections with LPC2148 have four I/O lines

required.

Pin Assignment with LPC2148

SPI Connector

LPC2148

Processor Lines

UA

RT0

(P1

)

ISP

PG

M

SCK P0.4

MOSI P0.5

UA

RT1

(P2

) MISO P0.6

CS P0.7



Circuit Diagram to Interface SPI-Ethernet with LPC2148

Source Code

The Interfacing UART with LPC2148 program is very

simple and straight forward, which controls the LED &

Switches in LPC2148 Slicker Board from Ethernet through

SPI. In C programs are written in Keil software. When we

select LED or Switch in Internet Explorer by using IP address

then the output is enabled in LPC2148 controller.

+3.3VJ10

HEADER 4X2

2468

1357

ETH_3.3V

ETH_CS

INT*_ETH

U23

74LS245

A02

A13

A24

A35

A46

A57

A68

A79

G19 DIR1

B018

B117

B216

B315

B414

B513

B612

B711

VC

C20

GN

D10

MISO_ETHWOL*_ETH

+5V

+5VR58 100E

+5V

R6110K

ETH_WOLETH_INT

MISO

C200.1uF

3.3V

C62

22pf

C63

22pf

X26

12MHz

LPC2148

U16

VSS16 V

DD

A7

VSS218

VD

D3

23

VSS325

VD

D2

43

VSS442

VR

EF

63

XT

AL1

62

XT

AL2

61

VSSA59

VD

D1

51

VSS550

P0.1238

P0.630

P0.529

P0.427

P0.1339

P0.1441

P0.1545

A1

A2

U21

RJ45

TD+1

CT4

TD-2

RD+3

CT5

RD-6

K2

11

A2

12

K1

10

A1

9

GND8

R54 56E

R53 56E

TD+

TD-

C240.1uF

C230.1uF

RD+

L2F-BEAD

R5956E

RD-R60 56E

ETH_3.3V

R49 1K C1910UF

TD

+

MISO_ETHWOL*_ETHINT*_ETH

R55 100ER57 100E

R52 1K

U18

ENC28J60

VCAP1

VS

S2

CLKOUT3

/I/N/T4

/WO/O/L5

SO6

SI7

SCK8

/C/S9

RESET10

VS

SR

X11

TPIN-12

TPIN+13

RBIAS14

VDD28

LEDA27

LEDB26

VDDOSC25

OSC224

OSC123

VS

SO

SC

22

VS

SP

LL

21

VDDPLL20

VDDRX19

VS

ST

X18

TP

OU

T+

17

TP

OU

T-

16

VDDTX15

R56330E

R50330E

Y2

25M

Hz

D12LED

A1

D13LED

A2

C21 22pf

RD+T

D-

RD-

C22 22pf

ETH_3.3V



C Program to interface Ethernet with LPC2148

*************************************************************************************** Title : Program to control LED & Switches from Ethernet using SPI

***************************************************************************************

#include <LPC214X.H>

#include "string.h"

#include "ENC28J60.h"

#include "c_ctype.h"

#include "conv.h"

#include "Utility.h"

#define ENC28J60_HALFDUPLEX 0

#define ENC28J60_FULLDUPLEX 1

const unsigned char httpHeader[] = "HTTP/1.1 200 OK\n

Content-type: "; // HTTP header

const unsigned char httpMimeTypeHTML[] = "text/html\n\n";

const unsigned char httpMimeTypeScript[] = "text/plain\n\n";

unsigned char httpMethod[] = "GET /";

const char *indexPage = "<HTML><HEAD></HEAD><BODY>\

<h1> ARM& LPC214x </h1>\

<h2> WEB SERVER </h2>\

<a href=/>Reload</a>\

<script src=/s></script>\

<table><tr><td valign=top><table border=2 style=

\"font-size:25px ;font-family: terminal ;\">\

<tr><th colspan=3>ADC</th></tr>\

<tr><td>AN0</td><td><script>document.write(AN0)

</script></td></tr>\

<tr><td>AN1</td><td><script>document.write(AN1)

</script></td></tr>\



</table></td><td><table border=1 style=

\"font-size:15px ;font-family: terminal ;\">\

<tr><th colspan=3>P1[31..24]</th></tr>\

<script>\

var str,i;\

str=\"\";\

for(i=0;i<8;i++)\

{str+=\"<tr><td bgcolor=blue>BUTTON #\"+i+\"</td>\";\

if(PORT1_31_24&(1<<i)){str+=\"<td bgcolor=green>ON\";}\

else {str+=\"<td bgcolor=#cccccc>OFF\";}\

str+=\"</td></tr>\";}\

document.write(str) ;\

</script>\

</table></td><td>\

<table border=2 style=\"font-size:15px ;font-family:

terminal ;\">\

<tr><th colspan=4>P1[23..16]</th></tr>\

<script>\

var str,i;\

str=\"\";\

for(i=0;i<8;i++)\

{str+=\"<tr><td bgcolor=orange>LED #\"+i+\"</td>\";\

if(PORT1_23_16&(1<<i)){str+=\"<td bgcolor=blue>ON\";}\

else {str+=\"<td bgcolor=#cccccc>OFF\";}\

str+=\"</td><td><a href=/t\"+i+\">Toggle</a></td></tr>\";}\

document.write(str) ;\

</script>\

</table></td></tr></table>\

This is HTTP request

#<script>document.write(REQ)</script></BODY></HTML>\

";

unsigned char myMacAddr[6] = {0x00, 0x1f, 0xD0, 0xE3,

0x90, 0xDD}; // my MAC address

unsigned char myIpAddr[4] = {192, 168, 1, 60}; //IP address

unsigned char getRequest[15]; // HTTP request buffer

unsigned char dyna[31]; // buffer for dynamic response

unsigned long httpCounter = 0; // counter of HTTP requests



int main (void)

{

PINSEL0 = 0;

PINSEL1 = 0;

PINSEL2 &= 0x0000000C;

delay_Nx10cyc(599999); // Delay 0,1s

IODIR1 &= 0x00FFFFFF; // Set P1[31..24] as inputs

IODIR1 |= 0x00FF0000; // Set P1[23..16] as outputs

IOCLR1 |= 0x00FF0000; // Turn off LEDs

// starts ENC28J60 with : RST bit on IOPIN0.13,

CS bit on IOPIN0.12, my MAC & IP address, full duplex

ENC28J60_Init(&IOPIN0, 13, &IOPIN0, 12, myMacAddr,

myIpAddr, ENC28J60_FULLDUPLEX) ;

while (1)

{

ENC28J60_doPacket(); // incoming Ethernet packets

/*

* add your stuff here if needed

* ENC28J60_doPacket() must be called as often as possible

* otherwise packets could be lost

*/

}

}

unsigned long putConstString(const char *s)

{

unsigned long ctr;

ctr = 0;

while(*s)

{

ENC28J60_putByte(*s++);

ctr++;

}

return(ctr);

}



unsigned long putString(char *s)

{

unsigned long ctr;

ctr = 0;

while(*s)

{

ENC28J60_putByte(*s++);

ctr++;

}

return(ctr);

}

unsigned long ENC28J60_userTCP(unsigned char *remoteHost,

unsigned long remotePort, unsigned long localPort,

unsigned long reqLength)

{

unsigned long

len, // my reply length

i, // general purpose integer

bitMask; // for bit mask

i = (unsigned long) remoteHost;

i = remotePort;

i = reqLength;

len = 0;

bitMask = 0;

if (localPort != 80)

return(0) ;

for (i = 0; i < 10; i++)

getRequest[i] = ENC28J60_getByte();

getRequest[i] = 0;

if (memcmp(getRequest, httpMethod, 5))

return(0);



httpCounter++; // one more request done

if (getRequest[5] == 's')

{

len = putConstString(httpHeader); // HTTP header

len += putConstString(httpMimeTypeScript);

IntToStr(0, dyna);

len += putConstString("var AN0=");

len += putString(dyna);

len += putConstString(";");

// add AN1 value to reply

IntToStr(0, dyna);

len += putConstString("var AN1=");



// add PORT1[31..24] value (buttons) to reply

len += putConstString("var PORT1_31_24=");

IntToStr(((IOPIN1 >> 24) & 0xFF), dyna);



// add PORT1[23..16] value (LEDs) to reply

len += putConstString("var PORT1_23_16=");

IntToStr(((IOPIN1 >> 16) & 0xFF), dyna);



// add HTTP requests counter to reply

IntToStr(httpCounter, dyna);

len += putConstString("var REQ=");



}

else if (getRequest[5] == 't')

{

if (isdigit(getRequest[6]))

{

bitMask = getRequest[6] - '0';// ASCII to integer



bitMask = 1 << (bitMask + 16);// create bit mask

if ((IOPIN1 & bitMask) != 0) // Toggled LED

IOCLR1 |= bitMask;

else

IOSET1 |= bitMask;

}

}

if (len == 0) // what do to by default

{

len = putConstString(httpHeader); // HTTP header

len += putConstString(httpMimeTypeHTML);// MIME type

len += putConstString(indexPage); // HTML page

}

return (len);

}

unsigned long ENC28J60_userUDP(unsigned char *remoteHost,

unsigned long remotePort, unsigned long destPort,

unsigned long reqLength)

{

unsigned long

len; // my reply length

unsigned char

*ptr;

ByteToStr(remoteHost[0], dyna); // first IP address byte

dyna[3] = '.';

ByteToStr(remoteHost[1], dyna + 4); // second

dyna[7] = '.';

ByteToStr(remoteHost[2], dyna + 8); // third

dyna[11] = '.';

ByteToStr(remoteHost[3], dyna + 12); // fourth

dyna[15] = ':'; // add separator

IntToStr(remotePort, dyna + 16);

dyna[22] = '[';

IntToStr(destPort, dyna + 23);

dyna[29] = ']';



dyna[30] = 0;

// the total length of the request is the length of the

dynamic string plus the text of the request

len = 30 + reqLength;

// puts the dynamic string into the transmit buffer

ptr = dyna;

while (*ptr)

ENC28J60_putByte(*ptr++);

// then puts the request string converted into upper char

into the transmit buffer

while (reqLength--)

ENC28J60_putByte(toupper(ENC28J60_getByte()));

return (len); // back to the library with the length of the

UDP reply

}

To compile the above C code you need the KEIL software.

They must be properly set up and a project with correct

settings must be created in order to compile the code. To

compile the above code, the C file must be added to the

project.

In KEIL, you want to develop or debug the project

without any hardware setup. You must compile the code for



generating HEX file. In debugging Mode, you want to check

the port output without LPC2148 Slicker Board.

The Flash Magic software is used to download the hex

file into your microcontroller IC LPC2148 through UART0.

Testing the SPI-Ethernet with LPC2148

Give +3.3V power supply to LPC2148 Slicker Board; the

SPI-Ethernet is connected with LPC2148 Slicker Board.

Connect your board to a hub with a straight cable. LEDA

should now turn on with LEDB still blinking. LEDA ON means

that the adapter is correctly linked to the network. The

network link LED of the other side hub should also turn on.

Open the Internet Explorer window and give the IP

address. If the entire connections are connected correctly,

then the IP address display the LED, switch levels.

Now you can control the input & output port lines (LED

& switch) of LPC2148 Slicker Board from Internet Explorer



through SPI - Ethernet. If you are not reading any output

from LED, then you just check the jumper connections &

check the LED is working.

If you are not controlled the I/O port lines of LPC2148

Slicker Board from Internet Explorer, then you just check

the IP address & Ethernet connections. Otherwise you just

check the code with debugging mode in KEIL. If you want to

see more details about debugging just see the videos in

below link.

How to Create & Debug a Project in KEIL.

General Information

For proper working use the components of exact values

as shown in Circuit file. Wherever possible use new

components.

http://youtu.be/EzOCple4POk



Solder everything in a clean way. A major problem

arises due to improper soldering, solder jumps and

loose joints.

Use the exact value crystal shown in schematic.

The straight cable only used between LPC2148 Slicker

Board hub & the network cable hub.

Don't plug the ENC28J60 in its socket, then power to

the board and verify the 3.3V power supply on each pin

of the ENC.

More instructions are available in following articles,

User Manual of LPC2148 Slicker Board.

Tutorial of how to create & Debug a project in

KEIL.

Interfacing LED with LPC2148.

Interfacing switch with LPC2148.

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ARM HOW-TO GUIDE Interfacing SPI- Ethernet with · PDF file25/12/2014 ·...

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Transcript of ARM HOW-TO GUIDE Interfacing SPI- Ethernet with · PDF file25/12/2014 ·...