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Topic: Reprogram Arduino's own microcontroller (Read 1 time) previous topic - next topic

Jack Christensen



Yes!


So - does no-one believe me, or was my link wrong, or what?


Sure I believe it. Was not aware of it. Not sure if I have a parallel port around though  :D
MCP79411/12 RTC ... "One Million Ohms" ATtiny kit ... available at http://www.tindie.com/stores/JChristensen/

sjheiss



Yes!


So - does no-one believe me, or was my link wrong, or what?


Sorry! Somehow I didn't see your post. But alas, I don't have access to a parallel port anywhere, so can't do that method.

westfw

You should note that ISP programmers for AVR chips are cheaper than parallel port cables :-)
http://dx.com/p/usbasp-usbisp-downloader-programmer-for-51-avr-157167

Paul__B

Only marginally cheaper though!

Now for the parallel cable, you need a DB-25 plug (or the adapter is a dollar cheaper if you have ripped the Centronics socket off an old printer); for the USBASP, you also need the 10 to 6 pin adapter - an extra couple of dollars there!

Cactusface


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Re: Reprogram Arduino's own microcontroller
« Reply #14 on: October 03, 2013, 07:36:52 pm »
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Quote from: Paul__B on October 03, 2013, 12:29:18 pm
Yes!

So - does no-one believe me, or was my link wrong, or what?

The only problem I see is, how many PC's not have a "Printer Port" ar'nt we all USB these days??
I too am very interrested in this question, being new to both the Arduinos and C as a programming language!!  But I do hope to produce a few stand alone projects just running on the Microcontroller, chrystal, etc..

Regards
Mel.
Open your mind! But not too far, your brains might fall out.
Also like Photography, model building and my 300+ Cacti and Succs.

Paul__B


The only problem I see is, how many PC's not have a "Printer Port" ar'nt we all USB these days??


Well, that's why I linked to USB-parallel interface cables.

In fact, all of my "desktop" computers have parallel ports, mainly because they are not the latest, and are business (HP-Compaq & Dell) rather than entertainment models.

fungus


The only problem I see is, how many PC's not have a "Printer Port" ar'nt we all USB these days??


I know people who have to keep dot-matrix printers around because they have to print triple-layer forms that require an impact to print the bottom layers.

No, I don't answer questions sent in private messages (but I do accept thank-you notes...)

Paul__B


I know people who have to keep dot-matrix printers around because they have to print triple-layer forms that require an impact to print the bottom layers.


And the interesting thing about the dot-matrix impact printers - they still work!

fungus



I know people who have to keep dot-matrix printers around because they have to print triple-layer forms that require an impact to print the bottom layers.


And the interesting thing about the dot-matrix impact printers - they still work!


Yep.

I gave up on inkjets long ago. I only use laser these days.
No, I don't answer questions sent in private messages (but I do accept thank-you notes...)

Cactusface

Hi,
      Like Fungus! I too use a cheap? Samsung laser, mainly used to help me make PCB's, etc. My PC like many others is home built, but by on means an entertanment machine, very much a good work horse, and my other machines a mac, when did you last see a parallel printer port on a mac, unless you put it there yourself?

I have a colour inkjet that as stood here for the last 2 years without being used.

But come on hav'ent we lost the track a little...

Regards

Mel.
Open your mind! But not too far, your brains might fall out.
Also like Photography, model building and my 300+ Cacti and Succs.

Brad Burleson


No, I mean I don't want to use any outside methods to program the chip. Just my computer and the Arduino. By programming I mean using a USBTinyISP or similar method for (re)loading a bootloader onto the chip.


How about http://www.pjrc.com/hub_isp/?

Regards,

Brad
KF7FER

westfw

Quote
that's why I linked to USB-parallel interface cables.

Those are typically "USB to Printer" cables that show up as a printer driver, which is quite different than a parallel port.  The AVR parallel port programmers work by manipulating individual bits of the parallel port, which is generally not possible on USB/Printer cables.  I haven't seen an example of anyone being successful programming an AVR at all through a USB/Printer cable, though I'd love to be proven wrong.

baselsw



Yes!


So - does no-one believe me, or was my link wrong, or what?



I believe you =).. The only thing is, you can rarely find a parallel port on a PC today..

//Basel

mrburnette

Quote
By programming I mean using a USBTinyISP or similar method for (re)loading a bootloader onto the chip.


So, I am taking it to mean that the Op is asking if it is easy to change the bootloader on the uC and the answer is YES.  It is basically a connectivity and timing issue... as shown previously, a Centronics parallel port can be utilized with PC software.  USBTinyISP uses an ATtiny uC to support the protocol.  Nick Gammon has a sketch that will fit on a 328 that stores a bootloader and is generally self-contained, using he PC only for handshaking and I have seen sketches where a similar trick is used with only a button on the board - making a fully self-contained battery operated bootloading device (Lady Ada had a video of this setup once upon a time.)

So, I personally would not consider a bootloader any kind of security since it purpose is to provide a simple mechanism to upload user programs.  This does not mean that the bootloader could not be written to manage some kind of key-exchange, but I think such bloat would be inappropriate.  At some point in time, one has to realize that the cost of the microcontroller is small if security is important and the engineers would likely just flash the chip and set the lock fuse.  Then, only a high voltage programmer could update the flash.


Ray


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