Saturday, October 25, 2014

How to select Microcontroller ?

Architecture (8 bits v/s 16 – 32 bits) :

8 bit µC are generally used by hobbyist, college students and for DIY projects. 8 bits µC belongs to 8085 like families but PIC and AVR are more famous makes. However for complex applications like DSP, image processing, RTOS and floating point arithmetic operations 16 / 32 bit µCs are preferred. To begin with one should get familiar with 8 bit µCs before moving to 16 or 32 bit architecture.


Programming language :

Available choice of the programing language is one of the most important aspect of selecting µC. Embedded C and Assembly language are the two popular options. Embedded C is more efficient, flexible and easy way write your code. Embedded C allows us to use your C skills with embedded programming. When the code size efficiency, time accuracy and processing speed does not matters much embedded C is perfect choice. Many Embedded C cross compilers are available, Keil µVision IDE is famous among all.

I/O ports, peripherals and memory :

Large verity of the ordering options are available with all the manufacturers ranging from 8 pin (e.g. ATtiny85) to 64 pin µCs. Generally speaking 4 IO ports (or 32 I/O lines) and integrated ADC, Timers, UART, PWM, JTAG are common features.

In memory options manufactures support FLASH memory from 1 Kbyte to 128Kbyte, EEPROM memory from 512 bytes to 4Kbytes along with SRAM ranging from 1 Kbyte to 4 Kbyte for 8 – bit controllers. For 32 bit larger memory models are available.


Cost :

For learners / hobbyist, it’s more likely that, you will end up in burned or non-functional µC in few initial attempts to program it. If you are rookie, no need to buy expensive once, it’s better to opt for low cost µC. In general 8051’s, ATmega AVR and PICs are few low cost options available.

Availability :

It’s always better to select µC which will be available for long time and available easily, but there is no rule of thumb for this. You can check our electronics shops nearby for this and make optimum choice. Having said this, 8051’s should be available all around same is the case for AVRs and PICs.


Online support:

It’s advised to select µC which has excellent only “Fan following”. It’ll make your life easy, if you’re stuck at some point. Getting the programming tricks, tool chains and hardware assembly online will allow you to complete your task quickly and more ease. These days AVRs and PICs have huge fan following and good online support available.

Packaging :

Hobbyist, college students and for DIY projects DIP packaging is most suitable one – easy to install – easy to replace. One can opt for SMD components to make circuit board compact but this option is valid only for professionals. 

Programmer boards:

Last but not least, a programming board. To make µC work one must program it (send hex file to µC). Wide choice of the programing boars are available now. Programming boards facilitate transfer of hex file from PC to µC. Generally speaking, USB based programming board is an optimum choice. Bunch of USB based programming boards are available for AVR and PICs, but for 8051 it’s bit difficult to find such board.