scrap collector implementation

8/8/2019 Scrap Collector Implementation

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IMPLEMENTATION SCHEDULE OF SCRAP

COLLECTOR

Electronics -- USB-FX2 Interface Board (USB-2.0)

[click to enlarge: 233kb JPEG]

This is a USB (universal serial bus) interface boardsupporting USB-2.0 high speed mode (480Mbit/s).

Features:

Throughput: Actual continuous transfer rates of

35Mb/s (mega bytes not bits).

Flexibility: On-board 8051 microcontroller with

16kb RAM.

FIFO IO: 8 or 16 bit wide, additional handshake

lines, 3.3V logic. Several USB endpoints and buffering

configurations (up to 512 bytes, quad-buffered);

bulk, isochronous and interrupt transfer.

Several additional free digital IO lines.

Firmware download via USB; optional non-

volatile 64kb EEPROM.

USB-powered and externally powered operation.

Very few discrete components.

If you would simply like to connect a microcontroller board to a computer

using USB but don't need massive bandwidth (less than 800kb/s), then you

may want to have a look at the smaller and cheaperUSB8Bit board.

[click to enlarge: 153kb PDF]

The main component is the CY7C68013A USB-2.0

interface IC ("FX2", actually it's "FX2LP" but don'tmind) fromCypress Semiconductorwith integrated

8051 microcontroller. Beyond that, really few externalcomponents are required.

It includes a 5V-to-3.3V low-drop regulator to provide

the 3.3V logic level. Access to all data, control,handshake and clock pins is granted via dedicated

connectors and allows direct interfacing to a variety of

high-speed devices (like AD/DA converters, hard drives,FIFOs, etc.).

For more information, have a look at the detailed circuit

description.
http://www.triplespark.net/elec/periph/USB-FX2/usb-fx2-r2-top.jpghttp://www.triplespark.net/elec/periph/USB8Bit/http://www.triplespark.net/elec/periph/USB-FX2/usb-fx2.pdfhttp://www.cypress.com/http://www.cypress.com/http://www.triplespark.net/elec/periph/USB-FX2/circuit.htmlhttp://www.triplespark.net/elec/periph/USB-FX2/circuit.htmlhttp://www.triplespark.net/elec/periph/USB-FX2/usb-fx2.pdfhttp://www.triplespark.net/elec/periph/USB-FX2/usb-fx2-r2-top.jpghttp://www.triplespark.net/elec/periph/USB-FX2/usb-fx2-r2-top.jpghttp://www.triplespark.net/elec/periph/USB8Bit/http://www.triplespark.net/elec/periph/USB-FX2/usb-fx2.pdfhttp://www.cypress.com/http://www.triplespark.net/elec/periph/USB-FX2/circuit.htmlhttp://www.triplespark.net/elec/periph/USB-FX2/circuit.html


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Step angle

It is angle through which motor shaft rotates in one step. step angle is

different for different motor . selection of motor according to stepangle depends on the application , simply if you require small

increments in rottion choose motor having smaller step angle.

No of steps require to rotate one complete rotation = 360 deg. / stepangle in deg.

Steps/second

The relation between RPM and steps per sec. is given by ,steps or impulses /sec. =(RPM X Steps /revolution ) /60

Pause between impulses can be shorter or longer and it defines

revolution rate. This rate cannot be infinite because the motor won'tbe able to "catch up" with all the impulses (documentation on specific

motor should contain such information). So referring to RPM value in

datasheet you can calculate steps/sec and from it delay orpause between impulses

INTERFACING TO 8051.

To cause the stepper to rotate, we have to send a pulse to each coil in

turn. The 8051 does not have sufficient drive capability on its outputto drive each coil, so there are a number of ways to drive a stepper,

Stepper motors are usually controlled by transistor or driver IC like

ULN2003.

Driving current for each coil is then needed about 60mA at +5Vsupply. A Darlington transistor array, ULN2003 is used to increase

driving capacity of the 2051 chip. Four 4.7k resistors help the 2051 toprovide more sourcing current from the +5V supply.

CODE EXAMPLE

To move motor in forward direction continuously

Connection -P1.0 -P1.3 connected to Coils A -D.


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EMBLY LANGUAGE C LANGUAGE (SPJ)

mov a,#66h ;Load step sequence

AGAIN

mov p2,a ;issue sequence to motorr a ;rotate step sequence right clockwise=Next sequence

call DELAY ;~ 20 msec.

jmp AGAIN ;Repete again

void main ()

{

TMOD = 0x20 ;

TCON = 0x40 ;TH1 = 0xf9 ;

TL1 = 0xf9 ;

PCON = 0x80 ;

SCON = 0x50 ;

while (1) /*continues loop */

{

printf("a"); /* transmit a along with CR & LF.

}

Basic Circuit for 8051

8051 PIN OUT

Power - Vcc, Vss

Reset - RST

Crystal - XTAL[1,2]External device interfacing

EA, ALE, PSEN, WR, RD

I/O Port P0[7;0], P1[7:0], P2[7:0], P3

P3 is shared with control lines

Serial I/O RxD, TxD, external interrupts INT0, INT1

Counter control T0, T1P0 and P2 are multiplexed with Address and Data bus


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EA/VP Pin

The EA on pin 31 is tied high to make the 8051 executes program fromInternal ROM

Reset Circuit

RESET is an active High input When RESET is set to High, 8051 goes

back to the power on state.The 8051 is reset by holding the RST high for at least two machine

cycles and then returning it low.

Power-On Reset

- Initially charging of capacitor makes RST High- When capacitor charges fully it blocks DC.

Manual reset

-closing the switch momentarily will make RST High.


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After a reset, the program counter is loaded with 0000H but thecontent of on-chip RAM is

not affected.

Oscillator Circuit

The 8051 uses the crystalfor precisely that: to

synchronize its operation.Effectively, the 8051

operates using what are

called "machine cycles." Asingle machine cycle is the minimum amount of time in which a single

8051 instruction can be executed. although many instructions takemultiple cycles.

8051 has an on-chip oscillator. It needs an external crystal thats

decides the operating frequency of the 8051.

This can be achieved in two ways,,

The crystal is connected to pins 18 and 19 with stabilizing capacitors.

12 MHz(11.059MHz) crystal is often used and the capacitance rangesfrom 20pF to 40pF.

The oscillator can also be a TTL clock source connected with a NOT

gate asshown

How fast 8051 works ?

A cycle is, in reality, 12 pulses of the crystal. That is to say, if aninstruction takes one machine cycle to execute, it will take 12 pulses of

the crystal to execute. Since we know the crystal is pulsing

11,059,000 times per second and that one machine cycle is 12 pulses,we can calculate how many instruction cycles the 8051 can execute

per second:

11,059,000 / 12 = 921,583

Why is such an oddball crystal frequency?


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11.0592 MHz crystals are often used because it can be divided to giveyou exact clock rates for most of the common baud rates for the

UART, especially for the higher speeds (9600, 19200). Despite the"oddball" value, these crystals are readily available and commonly

used.

Power Supply

C1-1000 mf ,C2-100 mf

The 78L05 is a 5V regulator. The input voltage ranges from 7V to 35V

and the output voltage is about 5V.

Using Ports for I/O Operation

8051 is TTL logic device. TTL logic has two levels: Logic "High" (1) andlogic "Low" (0). The voltage and current involved for the two levels are

as follows:

Level Voltage Current

High Above 2.4V Virtually no current flow

Low Below 0.9V1.6mA Sinking current from TTL input toground

(Depends on logic family)

1.Configuring for output

P0 is open drain. Has to be pulled high by external 10K resistors.


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Not needed if P0 is used for address lines

Writing to a port pin loads data into a port latch that drives a FET

connected to the port pin.

P0: Note that the pull-up is absent on Port 0 except when functioningas the external address/data bus. When a "0" is written to a bit in port0, the pin is pulled low. But when a "1" is written to it, it is in high

impedance (disconnected) state. So when using port 0 for output, anexternal pull-up resistor is needed, depending on the input

characteristics of the device driven by the port pin

P1, P2, P3 have internal pull-ups: When a "0" is written to a bit inthese port , the pin is pulled low ( FET-ON) ,also when 1 is written to

a bit in these port pin becomes high (FET-OFF) thus using portP1,P2,P3 is simple.

2. Configuring for input

At power-on all are output ports by defaultTo configure any port for input, write all 1s (0xFF) to the port

Latch bit=1, FET=OFF, Read Pin asserted by read instruction

You can used a port for output any time. But for input, the FET mustbe off. Otherwise, you will be reading your own latch rather than the

signal coming from the outside. Therefore, a "1" should be written to

the pin if you want to use it as input, especially when you have used itfor output before. If you don't do this input high voltage will getgrounded through FET so you will read pin as low and not as high. An

external device cannot easily drive it high

so, you should not tide a port high directly without any resistor.Otherwise, the FET would burn.

Be Careful :

Some port pins serve multiple functions. Be careful writing to such

ports. For example, P3.0 is the UART RXD (serial input), and P3.1 isthe UART TXD (serial output). If you set P3.0 to a '0', an externalbuffer (such as an RS232 level translator) cannot drive it high.

Therefore you have prevented receiving any serial input.

If an external interrupt such as EX1 on P3.3 is enabled, and set to belevel sensitive, and you clear this pin's output latch to a zero, guess


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what? You've just caused a perpetual interrupt 1. The pin's inputbuffer will read the output of it's latch as always low. Your controller

will spend all of its time in the interrupt handler code and will appearto have crashed, since it will have very little time for other tasks. In

fact, it will get to execute a single instruction before re-entering the

interrupt handler, so the rest of your program will execute very, veryslowly.

MACHINE CONTROL:

Three IR sensors are placed in the front of the machine. So the inputs can be considered

as a three bit word with the following possibilities of output

0 0 0(00h) the machine must continue moving straight.

0 0 1 (01h) the machine has encountered an obstacle in the left and hence has to move

right.

1 0 0(04h) the machine has encountered an obstacle in the right and hence has to move

left.

0 1 1(03h) the machine must move left twice and continue moving forward.

1 1 0(03h) the machine must move right twice and continue moving forward.

0 1 0(02h) the machine must use its arm.

1 1 1(07h) the machine must move back and turn left or right


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PROGRAM CODING FOR 8051:

mov b,#00;

mov a,#00;initial:mov a,p1;cmp a,#00;

jnz l1;

jmp drive;l1: cmp a,#01;

jnz l2;

jmp back;jmp right;

l2:cmp a,#04;

jnz l3;jmp back;

jmp left;

l3:cmp a,#03;

jnz l4;

jmp back;jmp left;


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jmp left;

l4:cmp a,#06;jnz l5;

jmp back;

jmp right;jmp right;


jmp arm;


jmp back;

jmp right;

l7:jmp initialhlt

drive:

mov ro,a;

mov a,#ffh ;Load step sequence

mov p2,a ;issue sequence to motor

rr a ;rotate step sequence right clockwise=Next sequence

acall DELAY ;~ 20 msec.mov a,ro;

ret;

back:

mov ro,a;





setb p3.1;

ret;

right:

mov ro,a;mov a,#66h ;Load step sequence




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acall DELAY ;~ 20 msec.

mov a,ro;

setb p3.2;

ret;

left:

mov ro,a;





setb p3.3;

ret;

arm:mov ro,a;

mov a,#ffh ;Load step sequence

mov r1,#50repeat:mov p2,a ;issue sequence to motor


acall DELAY ;~ 20 msec.dec r1;

jnz repeat;

mov a,ro;

ret;

PROJECT ESTIMATION:

OBJECTS-COST:

8051 microcontroller

Uln2038

Lm7235

Battery

Stepper motor

Usb 8051 driver

Body plate

Bread board

Connecting wires

scrap collector implementation

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