Password Protective Programming

Hi People,

So i'm wondering about this for a long time already , i would like to make my picaxe password protected when programming it.
Basically the IDE sends a password to the picaxe and its verified. In short i just want to be the only one capable of programming it.
It seems to be a thing at my school people find it funny to program other peoples kits because they don't have the proper stuff themselves.


Perferably something included in the bootloader part but i doubt if this is possible since it's 'Secret'.


Any ideas's on this? Im using Picaxe 20x2 and 20M2




Kind regards,
Orcanbull

Welcome to the PICAXE Forum.

There is no means available to password protect a PICAXE and it is unlikely that any could be added which could not be circumvented.

The only way to prevent others from programming a PICAXE is to deny them physical access to it.

You may need to talk to school staff to find a solution to the problem or get parents or guardians to talk to them.

Hi Hippy,

Thanks for the fast responds,
Well it has been an ongoing problem, i indeed currently prevent people from physically accessing the picaxe.
I was thinking of a unlock system, preventing the picaxe from going into flash mode

Kind regards,
Orcanbull

included in the bootloader part but i doubt if this is possible since it's 'Secret'.

Click to expand...

Are the cables easily accessible?

Some ideas :
- a password requested by PE6 giving the right to program or not a chip
- a hidden miniature switch shortening Rx/Tx connection

But, the best way is probably educating people as proposed by hippy.

You can almost prevent accidental re-programming, by those who don't know about the hard reset, by including code in your programme that effectively blocks the serial programming port. It's far from foolproof, as anyone who understands enough to know that the way around it is to power on the Picaxe after starting the programme download could defeat it, but it might work well enough for this purpose.

Orcanbull said:

Hi Hippy,

Thanks for the fast responds,
Well it has been an ongoing problem, i indeed currently prevent people from physically accessing the picaxe.
I was thinking of a unlock system, preventing the picaxe from going into flash mode

Kind regards,
Orcanbull

Click to expand...

If using serrxd, the Picaxe cannot been directly programmed : you'll need to use a hard reset.
Maybe enought ?

If you are not using the sertxd, you can also use a specific header to prevent students from using standard axe027...

Hi,

+1 to al of the previous replies:

For a "naked" chip, the simple solution is to ensure that you always have a copy of the most recent version of your program, for example on a USB drive. Reprogramming shouldn't take long, but I must admit that I still prefer to use PE5.

For a prototype board, there are several other possibiliies: A small magnetic reed switch would be hardly noticeable on the underside of a PCB, being made mainly of glass. It could be arranged to connect the programming pin (either input or output) only when you hold a magnet nearby.

Or a software/PIN solution might be possible if you can keep the PICaxe powered but asleep after a DISCONNECT. A 3v Lithium "Coin" cell (e.g. CR2016), or maybe power "borrowed" from a RTC, could keep the PICaxe "alive" via a diode or high value resistor. Then you would need to devise a program (to attach to your "main" program) to minimise power consumption, but wakeup occasionally and request a "PIN" if the programming input pin is held high (or you could force a hard reset by briefly disconnecting or short-circuiting the coin cell).

Cheers, Alan.

AllyCat said:

I must admit that I still prefer to use PE5.

Click to expand...

You're not alone, Boss. I still use mostly PE5 for myself, and exclusively for teaching noobs. PE6 is great for many reasons but has too many bells, whistles, and distractions for newcomers. It would be nice if there was a LITE version of PE6.

I tried PE6 and very quickly switched back to PE5, which sort of runs under Wine with Linux (well, it runs a LOT better than AXEPad, that crashes all the time when saving files).

I think the main issue may be that PE6 is aimed at Rev Eds main market, education, whereas for hobbyists PE5 probably does the job a lot better.

I use PE5 since it's the only stable app that will run under wine. Just to be on the safe side, some times I run the code under the linux compiler binaries, wich usually report a different byte count than the PE5.

I use PE5 because my old laptop still runs win 2000 therefore PE6 will not work.

Bill

I've used PE6 for nearly three years and would not think of reverting back.

@Orcanbull, I can understand your frustration. What you describe is a subtle and modern form of classroom bullying.

If you are designing your own hardware, a 4, 6 or 8-way DIL switch with individual switches in series or parallel with the serial-in wire from the socket or serial-out pin will make it a whole lot harder for someone else to interfere with your PICAXE. This would act like a binary combination lock. You could discuss a solution like that with your teacher.

Orcanbull said:

In short i just want to be the only one capable of programming it.

Click to expand...

How about snipping the "Serial Out" pin of the IC, so it no longer makes contact with the socket/breadboard/PCB ? Unless closely inspected, it might not even be noticeable.

(I assume a connection to this pin is essential for programming to occur).

It would be mighty inconvenient, but you could still re-program the chip, by holding a jumper to what remains of the pin...