Hi all ,
At the outset , let me clarify that this is NOT one of those - " which is better - AVR or PIC ?" question . Nor is it about which family is faster , has better structured ( pageless ! ) RAM , more registers instead of just one W reg. etc. etc .
The question here is a bit more esoteric . Please give a patient ear..
I have a product , running for last couple of years , based on PIC16F877A . It works in industrial power conditions where a lot of inductive loads are getting switched off frequently , thereby making the power line fairly noisy . The PIC has been working well.. No complaints at all like EEPROM corruption , frequent watchdog resets etc .
Recently , we switched to ATMega8515 , which is also a 5V device , also a 40 pin DIP package and since all we changed was the controller , the PCBs in both cases look very same . Majority of the tracks are routed identically and most importantly,the amount of ground plane is the same. 0.1 mfd ceramic in parallel to 10 mfd electrolytic very close to the pin 40 of 8515 , 3K3 pull-up on the reset pin , and a 0.1 mfd ceramic from the reset pin to the ground....all bases covered !
We then subjected the new product to our "contactor" test in which we power the product from the mains and also switch on/off an electro-mechanical contactor at a goodish rate , powered from the same mains..thereby corrupting the mains quality . We found that the newer unit gave us watchdog resets , once every while.
To pose the question now -
What is it among various controllers that make some more rugged than the others ? In this particular case , both are 40 pin devices , both are powered by 5V....
Some of you may respond with " if good design practices are followed..." stuff ...but does that apply to the kind of comparison I am making here ??
I seriously want to switch all my products to AVR , as I have had it upto my gills with the PIC.. but this "rock solid" issue needs to be addressed first .
All those of you , who have worked on industrial products based on AVR and may have faced similar issues , kindly throw some light on this..
Hi all ,