V.V.P.I.E.T / 2013-14 /

Introduction:-

Multipurpose digital display unit is an ARM7 Lpc2148 processor based project, which provides ease of communication between administration and students in colleges.

Whenever a notice is passed it can be directly displayed on the Digital notice board, without efforts like printing on a paper and then attaching it manually to the notice board.

Many of the students don’t have a habit of continuously check and read the notice board. But using digital notice board we can directly display it on a big LED display board, which can be easily seen and read by many students at a time.

Hence most of the students can quickly come to know what is the notice and the important message is conveyed to all. The notice keeps on rolling over and over.

The ARM7 controller core. Core is the key component of many successful 32 bit embedded systems. ARM cores are widely used in mobile phones handled organizers and multitude of other portable devices. Arm’s designers have come a long way from the first ARM1 prototype in 1985.
Objectives and Scope of work

To provide fastest medium that notifies and conveys important notices and messages, from administration to students within colleges and in bigger organizations. All with the only effort of typing and displaying.

This project can be widely used in colleges, organizations and in Government offices to notify student, employees and people. In future with more modifications such as the use of Bluetooth, use of graphics LED display, use of internet to directly display a webpage, etc.

Problem Definition:-

In Multipurpose Digital Display Unit we have to use a 16x96 led matrix display board that displays the message we type using a 4x4 aplhanumeric keypad.

We need an ARM7 Kit interfaced with a display and a keypad, along with an SPI memory to store the message entered through the keypad.

We also need temperature sensor, pressure and humidity sensor, to sense the respective parameters and a real time clock to keep running real time. These sensors are interfaced with the ARM7 processor and values of respective parameters at that time are displayed.

Following block diagram shows different blocks involved in Multipurpose digital display unit.

ARM LPC2148

Features

16/32-bit ARM7TDMI-S microcontroller in a tiny LQFP64 package

.

8 to 40 kB of on-chip static RAM and 32 to 512 kB of on-chip flash program memory.

128 bit wide interface/accelerator enables high speed 60 MHz operation.

In-System/In-Application Programming (ISP/IAP) via on-chip boot-loader software.

Single flash sector or full chip erase in 400 ms and programming of 256 bytes in 1ms.

Single 10-bit D/A converter provides variable analog output.

Two 32-bit timers/external event counters (with four capture and four compare

channels each), PWM unit (six outputs) and watchdog.

Low power real-time clock with independent power and dedicated 32 kHz clock input.

Single power supply chip with Power-On Reset (POR) and BOD circuits:– CPU operating voltage range of 3.0 V to 3.6 V (3.3 V ± 10 %) with 5 V tolerant I/O pads

Processor wake-up from Power-down mode via external interrupt, USB, Brown-Out

Detect (BOD) or Real-Time Clock (RTC).

Up to 45 of 5 V tolerant fast general purpose I/O pins in a tiny LQFP64 package.

Architecure of Lpc 2148

Crystal oscillator

While an input signal of 50-50 duty cycle within a frequency range from 1 MHz to 50 MHzcan be used by the LPC2141/2/4/6/8 if supplied to its input XTAL1 pin, thismicrocontroller’s onboard oscillator circuit supports external crystals in the range of 1 MHzto 30 MHz only. If the on-chip PLL system or the boot-loader is used, the input clockfrequency is limited to an exclusive range of 10 MHz to 25 MHz. an oscillation mode as an on-board oscillator mode of operation limits FOSCclock selection to 1 MHz

to 30 MHz.

General Purpose Input/Output ports (GPIO)

Every physical GPIO port is accessible via either the group of registers providing an enhanced features and accelerated port access or the legacy group of registers

• Accelerated GPIO functions:

GPIO registers are relocated to the ARM local bus so that the fastest possible I/Otiming can be achieved

Mask registers allow treating sets of port bits as a group, leaving other bits unchanged

All registers are byte and half-word addressable

Entire port value can be written in one instruction

Bit-level set and clear registers allow a single instruction set or clear of any number of

bits in one port

Direction control of individual bits

All I/O default to inputs after reset

Backward compatibility with other earlier devices is maintained with legacy registers

appearing at the original addresses on the VPB bus

SPI MEMORY

Single complete and independent SPI controller.

• Compliant with Serial Peripheral Interface (SPI) specification.

• Synchronous, Serial, Full Duplex Communication.

• Combined SPI master and slave.

• Maximum data bit rate of one eighth of the input clock rate.

• 8 to 16 bits per transfer

Methodology:-

We implement this project using an ARM7 processor. The processor is lpc2148, which is interfaced with 16x96 Led Matrix display, and a 4x4 matrix keypad. These are used to display and enter the message to be typed respectively.

ARM7 interfaced with 8x8 led matrix display is shown in fig below

8x8 LED Matrix with SPI Interface:

The 8x8 LED matrix is the most advanced circuit on the board, at least when it comes tocontrolling it. Figure below illustrate the 8x8 LED matrix part of the design. Two shiftregisters (serial-input, parallel-output), 74HC595, are used to control the eight columns androws respectively. 16 bits must be shifted (= 2 bytes) in order to update the two shiftregisters. The first byte sent controls the rows and the second byte the columns. A zero bit inthe first byte will light LEDs for the corresponding row and a zero bit in the second byte willlight LEDs for the corresponding column. Fig 8x8 led matrix interfacing

ARM7 displayed with 4x4 keypad to type the message to be displayed:-

In case of 4X4 matrix Keypad both the ends of switches are connected to the port pin i.e. four rows and four columns. So in all sixteen switches have been interfaced using just eight lines.

Fig. interfacing of 4x4 keypad with lpc2148

The Interfacing keypad with LPC2148 program is very simple and straight forward, that scan a keypad rows and columns. When the rows and columns are detected then it will display in PC through UART0.

Software requirements:-

  1. Keil uvision compiler(ARM)
  2. Embedded c
  3. Express PCB
  4. Flash Magic
  5. Adobe reader (to view manuals and datasheets)

Hardware requirements:-

  1. LPC2148
  2. 16x96 LED Matrix display
  3. 4x4 Matrix alphanumeric keypad

Cost Estimation:-

Sr no. / Name of the Component / Quantity / Cost(Approximate)
1 / Lpc2148 kit / 1 / 2785/-
2 / 16x96 LED matrix Display / 1 / 3500/-
3 / 4x4 Alphanumeric Keypad / 1 / 250/-
4 / I2C bus / 1 / 120/-
Total cost= 7155/- (approx)

WORK PLAN

Sr. No / Date / Work / Sign
1 / 20/07/2013 / Area of Interest
2 / 27/07/2013 / Domain selection
3 / 03/08/2013 / Problem Definition
4 / 10/08/2013 / Literature Survey
5 / 17/08/2013 / Theoretical and mathematical modeling
6 / 24/08/2013 / Component search
7 / 05/10/2013 / Simulation
8 / 12/10/2013 / Emulation
9 / 03/11/2013 / Final
10 / 25/11/2013 / Result

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