HOW TO USE 8051

Simulating and debugging your micro-controller project is fun on a computer using Proteus or similar software but when it comes to practical implementation, it's a bit complicated, or I would say "a headache", to get things done. Its not as simple as mounting the IC on bread board and expecting some output straight away. You have to take care of the "protocols" to achieve your target. You must provide the micro-controller unit (MCU) with proper connections for proper start-up and output.

UPDATE: Visit this link for an updated version of this post - with more details and insight.

Let me assume that you have successfully perfected your code and have burned/programmed it to the MCU. Now you need to mount this MCU on a bread board or vero board and implement the whole of your project. What's important is that you don't need a power circuit in Proteus with the MCU for simulation so it didn't matter but on a bread board, it surely does. 

REQUIREMENTS

An MCU must be provided with the following on a bread board

• Power Supply
• Reset Circuitry
• Clock Source

TEST CIRCUIT FOR 8051

Here is an image showing the necessary circuit for 8051 MCU. 

Test Circuit for 8051

You must implement this circuit if you want your project to work. The Reset Circuitry will automatically RESET the MCU at start-up but you can always use the push button S1 to reset the MCU anytime. You can also use a different crystal oscillator according to your requirements. For example, to generate standard baud rates for serial communication through the MCU, you must use 11.0592 MHz oscillator. 

CONCLUSION

This circuit can be considered as a "pre-requisite" for 8051 projects. You have to use this if you want your project to work so always keep these required components at your disposal. The diagram may seem a little complicated but it looks pretty simple and neat when you implement it practically. You will get used to it in no time at all, I promise.