Attiny85 fuses / bricked [mysteriously solved]

Programmed the attiny once with isp with default fuses, now it is unresponsive

-U lfuse:w:0x62:m -U hfuse:w:0xdf:m -U efuse:w:0xff:m

http://www.engbedded.com/fusecalc/

Anybody have a suggestion as to why is this or what fuses to use ?

It shouldn’t brick with that fuses.
may be programmer have issue because of 1MHz attiny clock
once I had similar issue with attiny13 with 600Khz clock. problem solved by slow SCK jumper

ok will take a look at my usb isp if it has that jumper, or if not it seems I can manually bridge it

edit: I have this isp

http://www.ebay.com/itm/New-Tiny-USBASP-AVR-Programmer-Adapter-10-Pin-Ribbon-Cable-USB-ATMEGA8-ATMEGA128-/171281699831?hash=item27e12f53f7

but the JP1 jumper which should be the slow SCK jumper, is marked as “5V 3.3V”

I believe it’s a command line entry that you use to slow the baud rate to the IC

I already did try this, but with no response (this below is not my log, it’s from the instructions page)

C:\AVR>avrdude -p attiny13 -P usb -c usbtiny -tuF

avrdude: initialization failed, rc=–1
avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.00s

avrdude: Device signature = 0x000000
avrdude: Yikes! Invalid device signature.
avrdude: Expected signature for ATtiny13 is 1E 90 07
avrdude> sck 1000
>>> sck 1000
avrdude: Setting SCK period to 250 usec
avrdude> e
>>> e
avrdude: erasing chip
avrdude> sck 10
>>> sck 10
avrdude: Setting SCK period to 10 usec
avrdude> quit
>>> quit

avrdude done. Thank you.

will also try this:

Keep us posted if you figure it out… I’ve had a few 85s for some time now but not put them to use yet.

Absolutely. I have a few ideas what code we could put into 8k space. Ordered some more 85s and avrdragon.

PM DrJones, he uses the 85 (I’ve got multiple from him) so he definitely knows how to do it.

Of course, I had already ordered avrdragon and 16 more 85s after bricking 2 tiny85s last night… and now I honestly don’t know what unbricked it, but now it seems to be responsive, I have strobe running!

when I unbricked it I set fuses to this 8mhz without /8 divider:
-U lfuse:w:0xe2:m -U hfuse:w:0xdf:m -U efuse:w:0xff:m

I also built development bench with relays which gives me the possibility to “unclip” by breaking the 6 SOIC clip leads using relays, so no need to physically unclip anymore.

Will let you know when I manage to port windows95 to this.

edit: for future reference I tried changing the jumper on the usb isp from 5V to 3.3V, that didn’t help. Then tried using avrdude with -B 3, -B 2, and -B 1, and setting sck 1000, and erasing with “e” that didn’t work but some time later after powercycle it became responsive, and I immediately changed fuses to not use /8 divider.

my avrdragon has not yet beed delivered, I only have usb isp. So something else automagically happened :slight_smile:

no great deal. Ordered it from mouser, should cost 44€+VAT, shipping was free over 65€ so I added few more 85s to get there. I’m hoping that debugging will be easier, and also I get access to HV, so I can experiment with fuses and gain another i/o (reset pin).

Managed to get star offtime running on tiny85, rewrote eeprom storage routines, most of everything else didn’t require modifications, so programming for 85 is practically the same as for 13a but it’s SO much easier to experiment with more memory and the relayed-unclipping bench that I made.

Now I’ll think about what I can do to fill up the 8k available memory :slight_smile:

Since the attiny85 is no longer bricked (actually one is but I have another one running) - I can consider this topic closed and when I have something interesting to share, I’ll open another topic.

also, need to see if 85 can be soldered in place of 13a on nanjg105c without pin origami, It seems it should be possible.

signing off

this useful idea will be prioritized high :slight_smile:

Already done...

crap. What can I do then? What mountain has not been climbed yet? Was it all in vain?

Thanks for the components! Here’s what I did with them, slightly different setup than yours:

I wired the power button directly to the driver, just in case the 2A relays aren’t up for the job when I test with 6A or above. The switches are rated even lower, but much easier to replace if they fry… So my two buttons are independent of each other, meaning two presses over your single press (one to “unclip”, one to power up the driver). But I can live with that, it’s soooo nice to not have to unclip the darn clip each time :beer:

yep, relays have too high resistance, so not adequate for anything above 2A in my experience, so yes. I advise anybody doing code for any of the attiny’s to do somthing like this. One button to electrically unclip the SOIC clip, without having to physically unclip it. A time saver when testing out new code.

edit: this relays were used:
http://www.ebay.com/itm/281489706492?\_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

for switches it can be whatever you have at hand, I used these:
http://www.dx.com/p/self-locked-2-pin-push-button-switches-green-black-20-piece-pack-137480