Which chip do i use?

[The Master]

I would ask Matt but hes never online anymore. Hes always busy.

From what ive learned in this thread and looking at the top of his PCB i think i can see how and why he has connected certain things up. Im gonna get hold of a 16MHz resonator and borrow one of the chips from the boxes. If i can get one of the origional chips to work then i could simply copy the code but i have an idea of how he programmed it too so i can also experiment with that.

Whats wrong with reverse engineering anyway? I tend to learn best by seeing a finished product then looking at all the bits in it to see how it works. It also leads to me question why it has been done in such a way. Like why does Matt appear to have used a method that nobody has mentioned here?

[mackrackit]

Like why does Matt appear to have used a method that nobody has mentioned here?

You would have to ask him. There are many ways to do the same thing. Is one better than the other, who knows. This thread was not started about why some one did a project a certain way. It was about which chip would work. Then it went on to interrupts.

As far as reverse engineering.

Using it to lean is one thing but to duplicate a product is on the verge of stealing.
If the product is open source that is something else.
Want to build a device that works like one made by someone else, fine. Use your own ideas and you will get help on how to make them work. Want it to be exactly like the one made by another, buy one from them.

[The Master]

I dont want it to be exactly the same. Thats why im putting so much effort into learning this. Im doing loads of tests on Matts box now and theres a few things i still dont get but im getting there. Just about to try some code out (stuff i invented myself). But im gonna put it on one of the boxes Matt made. I know the box works perfect so i can test my code better. Once i get my code working then it will help me understand the circuit better.

I dont want to "copy" Matts design. I want to figure out how he did it then do it in my own way

[mackrackit]

OK

Some chips have an internal MCLR , I like these for ICSP.

Let us know how you code works out and where you need help from there.

[The Master]

Im stuck already. You knew it wouldnt be long :P

Im using a 16MHz oscillator. In my code i have put "define osc 16". The rest of the code simply turns an LED on an off a few times to show the chip is working.

What im getting is a quick flash when it powers up and when it powers down.

I think this might be to do with the fuse settings. What should the following be set to?

WDT
PWRTE
BODEN
LVP
MCLRE (i assume E means external so Matt had this disabled)
Oscillator
Code Protect (i know this should be disabled)

for Oscillator i have the following options to choose from
ERCLK
ERIO
IRCCLK
IRCIO
EXTCLK
LP
XT
HS

The other options are enabled/disabled.

BTW. Do you want me to start new threads for any questions about this or stick to this one? Its all the same project

Edit: Im using a PIC16F627

[mackrackit]

MCLRE is just the name.
For internal (Not used for reset but the pins other functions) the fuse should be
_MCLRE_OFF

HS for the OSC

[The Master]

Woo it works Its a bit fast though. i put 100ms pauses in and it flashes a lot faster than when i use a 4MHz resonator. I know 16MHz is 4 times faster but i thought the point of declaring that was so "pause 100" would still take 100ms and not 25. Maby ive got something else wrong. I was reading about timers in the datasheet. I didnt understand any of it but part of it could mean the chip runs 4 times faster than the resonator you use.

It doesnt matter anyway. If i want 100ms then i just type 400. The point is the LED flashes. Tomoz ill get onto the real code but its 10:00 now so i should be getting to bed. Up at 4:30AM for work

Anyways. Thanx for that. I would have been lost trying to figure it out myself