Hi SpeedEC,
Looks like I have no choice ;o)
Hope you have lots of patience...
I am in the middle of an urgent product design, urgent meaning I have to order components within the next couple of days. Which means I must settle the design before then. Programming etc can be settled over the next couple of weeks.
It is a very basic design, with the intent of using a PIC to trigger another porcessor's power ON line very 8 hours for 1 sec. The other processor will shut down itself after performing certain tasks.
The PIC must monitor an Input, which will be controlled by the other processor, if the other processor is running it will pull down the Input, in which case the power ON line must not be triggered as it is also used to unconditionally shut down the other processor.
A tamper switch must be monitored through an input, any status change will change the status of a seperate output(which will indicate that status to the other processor). This must trigger the other processor's power ON line and keep the output in the changed state for 3mins and only change the state back if the input changed.
As I said, I need to complete the physical design pretty urgently, need to buy the dev and programming kit, then do the programming. Please advise how to proceed. I am based in Indonesia, so can probably get the kits etc only from Singapore.
What do I need and where do I start?
I had a look at the PIC16F1827 as recommended, 18Pin DIP package is good enough for now, I will re-design and look at space saving later.
I will be using a 3.45V battery with 470uF cap and diode as power supply to both.
The other processor will power a GSM modem.
1. Do I need to split/isolate the power supplies?
2. If they are on the same ground plane, can I drive inputs and outputs directly or do I need to isolate them?
Thanks a lot!