Dear Raghu,

I have soldered the following components to the main board:
-On/Off Switch for power with led indication.
-MCU reset by using capaitor.
-11.0592 crystal
-Max232
-Chagnge over switch for ISP/Normal mode
_connected headers of 8 connections to port P0,P1,P2 & P3. for connecting the other experimental boards.(I want to keep the main board neat & clean)
-Connected P0 port with 10K pull up resistors.
-prepared another board (Board No. 2) with 8 push buttons, 1 DIP switch as input and 8 LEDs as out out.
_connected Main Board with the Board No. 2 with ribbon cable connectors and tried
out the following programms:-

-Port P1.0 as input by push button
-Port P2.0 as output glowing led as long as it is pressed
-Tried with different timings.

-Glowing all the Leds one by one.
-Glowing LEDs in sequence with different timings.
-used 330 ohms resistances for lEDs

-using different ports as input/output by changing the Input / output ports
and timers.

Sunday was real fun playing with this little machine.
- connected LCD 2x16 characters with keyboard, managed to display cursor
and all the sixteen characters by pressing their respective key buttons. It was
not a easy job, I programmed, loaded tested again and again. I don't have the debugging tool. struggled with Keil debugger,afterwards tried hit and trial
method with flash magic till the time it started working .


OK now my project will consist of the following:
For example:


DIs:
-Overcurrent switch will use DIP switch to simulate as a O/C
-Temerature Switch will use DIP switch to simulate as a A TEMP SWITCH

DO:
-K1 Relay
-K2 relay
-K3 relay
-K4 Contactor

Let us assume that:-.
A motor is to be started with main contactor K. K is energized through safety
relay K3. Safety relay K3 is energized through relays K1 and K2.

Is it Ok ?


Thanks

Rashu