8051 Timer Operation

8051 Timer Example : To generate a 2sec ON and 1sec OFF PWM pulse by using Timer 0 Mode 1 16-bit operation.

#include <reg51.h>

#include <stdio.h>

sbit pwm = P1^0;

void Timer0_delay(unsigned char);

void main()

{

  while(1)

  {

  pwm = 0;                     //port  1 pin 1 is  low

  Timer0_delay(100);  // 1sec time delay by using  timer

  pwm = 1;                    //port  1 pi1 1 is high

  Timer0_delay(200);  //2sec  time delay by using  timer

  }  ;

  }

void Timer0_delay(unsigned char x)

  {

  for (;x>0;x--)                         // loop rotates up to above given value.

  {

  TMOD = 1;                          //Timer  0  mode 1 16-bit operation

  TH0 = 0xD8;   //load register value by calculating 65536-10000=55536

  TL0 = 0xF0;    //55536 hex value is 0xD8F0 load this value to register.

  TR0 = 1;         //  command is used to start timer  and  increment  the

  while(TF0!=1);  //TH TL register values up to  over  flow  will occur.

  TF0=0;               // timer  0  over  flag we need to reset again use.

  };

  }

I2C (inter integrated Circuit) protocal

if you have any doubts check my video on youtube 

https://www.youtube.com/watch?v=f6FpEHi8ZDg

MULTIPLEXER with REAL TIME EXAMPLE

Definition: In electronics, a multiplexer (or mux) is a device that selects one of several analog or digital input signals and forwards the selected input into a single line. A multiplexer of 2ⁿ inputs has n select lines, which are used to select which input line to send to the output.

REAL TIME EXAMPLE FOR MULTIPLEXER :

Sometimes we need to Display four values in one LCD O/p Screen so what should we do ? The answer is so simple we use a keypad or any input to select what we need to display .

That signal is input for micro controller and it produces two output signals which we use as select lines to the Multiplexer so that we can select one o/p signal out of four inputs.

The Multiplexer output is fed to the Micro controller, Inside micro controller converts Analog to Digital and it sends to output port to the LCD Display.

The LCD Display’s the required values, all this process is done by msec.

Note :  we will use a Driver circuit in between sensor and multiplexer and multiplexer output can be a digital or analog depends on inputs. 

Roles and Responsibility's of Component Engineer.

Component Engineer Roles and Responsibility's :

1. Component Engineer mainly works to maintain the Production of Product's continuously without any Failure's.
2. Component Engineer identifies alternatives for obsolete components.
3. Reduce the cost of production by suggesting The component which have less cost and same characteristics.
4. Increase the efficiency of the Product by analyzing the Test Reports of Products.

There are many types of request you will get from engineer and some of the topics i will discuss here: 

1.BOM(Bill of material) SCRUBBING :

BOM Scrubbing means we have to identify all the components which are present in BOM are ACTIVE and ROHS (Reduction of Hazardous Substance) compliance are not. If all the component are ACTIVE and ROHS compliance then we no need to do anything. If any component is not ACTIVE or ROHS Compliance then we have to identify the alternate component for that part which have ROHS compliance and cost also need to take criteria.

we have to update all the BOM Components  to ACTIVE and ROHS compliance. If we can't find any Component to  identify the environment where the component is used if it is compulsory ROHS then suggest to change the design for design engineer.

2.Identify  the alternate for OBSOLESCENCE components : 

1. Whenever the Existing Component is Obsolete we have to identify the alternate Component to the Obsolete component to maintain continuous Production without any break.
2. go to the manufacture's website and see for the part status is active or not and check the quantity in distributor's list (DIGI KEY, MOUSER ....) also.
3. suppose in manufacture website don't find out the part status is active or not then check for stock other wise ask the manufacture for that part status through mail or phone.

Reasons for component Obsolete ?

There are many reason behind the component Obsolete some of the scenario's i will discuss here : 

When the Component manufactures stop the Production due to less demand for that component so we will get affected by this action 

OR

    

There is a technology development the component manufactures improve the component with new developments which will change the component physical dimension or characteristics so that they stop the existing Product and start the New Product Development then we will get Affect by this.

 OR

The existing Component is not a ROHS compliance due to this the government Ban or component manufactures decide to go stop that Part production.