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Electronics => Electronics => Topic started by: zuazons on May 22, 2009, 07:48:46 PM

Title: Problems with my Axon MCU
Post by: zuazons on May 22, 2009, 07:48:46 PM
Guys,

I bought an Axon MCU and an AVRISP mkII, both were working, but now when i try to load "Read Signature" I have the following error: "ISP Error".

In some point the battery voltage was low. Could  the AVRISP generate some bad programing in the Axon MCU?.  Can I restore the Axon parameters to the Factory?

The AVRISP detec the processor pero I can not entry in ISP mode, I tried to change the ISP Frecuency and I have the same error.

could someone help me?


PD: I am attaching the images with the error
Regards,
Neptali
Title: Re: Problems with my Axon MCU
Post by: sonictj on May 22, 2009, 09:19:26 PM
Are you getting two green lights on the iispmkii?  One signals you have the programmer plugged into your computer the other signals the connection to the mcu is correct.

Quote
In some point the battery voltage was low. Could  the AVRISP generate some bad programing in the Axon MCU?.  Can I restore the Axon parameters to the Factory?

I doubt there is anything to worry about, but there is a very slim possibility a lucky fluctuation of voltage may have changed the fuse settings. First what is your battery voltage?  If your battery dips to low this will cause a reset to the mcu which I believe will cause this type of error.

you can set the axon back to the default shipping firmware simply by burning the corresponding hex file, which I'm sure Admin supplies.

I suggest you recharge your battery and try programming the board again.  If the ispmkii shines something other than a green led when plugged into the axon you can find a lookup chart in avr studio that explains the corresponding errors.  in avr studio help/avr tools user guide then in the new pop up window click on the user guide (under ispmkii picture) then troubleshooting guide.

 
Title: Re: Problems with my Axon MCU
Post by: sonictj on May 22, 2009, 09:24:01 PM
Also I know I mentioned fuses.  DO NOT MESS WITH FUSE SETTINGS UNLESS YOU KNOW WHAT YOU ARE DOING!  You can brick the board if your not careful.  I highly doubt that is your problem anyway.
Title: Re: Problems with my Axon MCU
Post by: zuazons on May 22, 2009, 09:36:36 PM
yes, i have two green lights on the AvrISP MKII. The AvrISP detect the processor, but I can not write the program in the Axon

The battery had 3.5 volts when the problem happened.

Title: Re: Problems with my Axon MCU
Post by: sonictj on May 23, 2009, 02:33:56 PM
have you tried charging the battery?  depending on the fuses Admin set, a voltage of 4.5V could reset the chip.
Title: Re: Problems with my Axon MCU
Post by: zuazons on May 23, 2009, 03:03:17 PM
Yes, i tried with the battery to full and i have the same problem. I tried to configure the fuses with default values, but the ISP mode must be ok in order to put values in the processor (i have "ISP error") .

I got the default values for Axon fuses in : http://www.societyofrobots.com/axon/axon_FAQ.shtml (http://www.societyofrobots.com/axon/axon_FAQ.shtml)


Title: Re: Problems with my Axon MCU
Post by: sonictj on May 23, 2009, 03:26:36 PM
You may want to try upgrading the firmware on the ispmkii this helped me before.  Just go the the tools tab in avr studio.

what type of battery are you using?  If you have a link to it that would be great.
Title: Re: Problems with my Axon MCU
Post by: Admin on May 23, 2009, 10:33:47 PM
Quote
The battery had 3.5 volts when the problem happened.
As sonic said, under rare occasions a low voltage can cause an error in programming which could set fuses that would brick your Axon (or any ATmega microcontroller).

It appears you already tried programming at 125KHz . . . try at other speeds, both slower and up to 250KHz.

And then the technique to unbrick your Axon . . . it isn't easy, but its the cheapest thing to do without buying a new Axon:
http://www.societyofrobots.com/axon/axon_FAQ.shtml#brick (http://www.societyofrobots.com/axon/axon_FAQ.shtml#brick)
Title: Re: Problems with my Axon MCU
Post by: sonictj on May 24, 2009, 06:22:04 AM
if you have another avr chip you can program you can test to see if the ispmkii will program it.  This will tell you if the problem is the programmer or the axon.
Title: Re: Problems with my Axon MCU
Post by: zuazons on May 24, 2009, 08:53:20 AM
I tried with other speeds  less to 250 and nothing. I have the same error.
Title: Re: Problems with my Axon MCU
Post by: Admin on May 24, 2009, 09:02:53 AM
Yea I'm pretty sure you bricked your Axon.

You can also use another microcontroller to generate a clock signal using PWM.
Title: Re: Problems with my Axon MCU
Post by: zuazons on May 24, 2009, 09:13:31 AM
I do not know how to do that (PWM). Do I need buy another hw?



I am worry about to use the another option "Unsolder the crystal and the two small capacitors next to it, apply a 16MHz square wave to XTAL1, then using a hardware programmer change the fuse settings back to a 16MHz crystal. Lastly, solder the crystal and caps back on. "
I prefer that someone with experience to do this

Do you know a technical services that can to do that?

Thank for your help


Title: Re: Problems with my Axon MCU
Post by: Admin on May 24, 2009, 09:30:35 AM
Don't feel too bad, I've bricked microcontrollers too when I was new to them. Break this up into steps.


First, unsolder the components. The crystal is that rectangular silver thing under the big black ATmega chip. And under that you'll see you tiny little chips that look the same, those are the capacitors.

Then you'll need something that generates a PWM signal, like another microcontroller, or a function generator. Have either?


When I bricked my stuff, I just bought a new microcontroller. You can always use the new one to unbrick the old one.
Title: Re: Problems with my Axon MCU
Post by: zuazons on May 24, 2009, 09:44:09 AM
I do not have a function generator, but i have a BASIC Stamp Microcontroller. Can use this Microcontroller to do that?

Maybe I need to buy another Axon MCU.

Thanks.
Title: Re: Problems with my Axon MCU
Post by: Admin on May 24, 2009, 09:56:49 AM
Yeap you can use a BASIC stamp. Tell it to do a PWM at a frequency that AVR Studio can do, like 125KHz, or 250KHz, for example. (you may have to google a bit to get that working)

Then program the fuses listed in the Axon FAQ using the ISP programmer. This will let it use the crystal again.

After that works, solder the crystal and caps back on.
Title: Re: Problems with my Axon MCU
Post by: zuazons on May 24, 2009, 10:31:35 AM
Thank you man, I will do that.
Title: Re: Problems with my Axon MCU
Post by: zuazons on June 07, 2009, 10:18:01 AM
Thanks Admin!!

I unbricked my Axon MCU.

I did not removed the crystal. I removed two points of contact in back of the board, after this I applied a PWM of 100 Hz with my BS2 Stamp processor and reprogrammed the fuses with the AvrISP MKII .

I am attaching the pictures with the points of contact that I removed.

Thanks again.