dual 7-segment countdown timer code

[mister_e]

it can be useful in few situation : tight space, mass production with tight budget, Push-button handling, prototyping, etc etc. They're weak, and may cause some problem (noise, ESD, strange behaviour, etc etc) one day or another. I got few ESD and erratic problems in the past with that in noisy environment, since i add external one, no more problem!

It's a long debate, some never ever had problem with... too bad i no longer take the risk.

[precision]

Thanks, one more Q. please
what should we use instead of output pin / input pin. I mean tbe best way to make input output pin ?

.

[BobK]

Hi Precision,

I think what Mister E is saying is always use an external resistor either in a pull up or pull down situation. Don't make an unused pin an output and just leave it floating. Look at the data sheet for the particular PIC you are using and search for the state of the pins ON RESET. If you are leaving a number of pins unused and they start as inputs on powerup or on reset then you need to make sure they are properly terminated with a pullup or pulldown resistor.

HTH,

BobK