My atTiny26 is ignoring everything I do.
April 2, 2006 6:56 PM   Subscribe

I'm trying to program an atmel atTiny26 using an STK500 and AVRStudio, but I seem to be unable to read or write to the chip: even the signature reads as FF FF FF. It's a brand new chip, and I've checked the wiring a few times (but could still be wrong).

I have the ISP6PIN port going to the SPROG1 port, the chip in SCKT3700A1, PROG CTRL connected to portD, PROG DATA to portB, and jumpers mounted on VTARGET, AREF, RESET, XTAL1 and pins 1 and 2 of OSCSEL. I'm totally stuck. I've tried a different STK500, and got the same result, but I don't have another chip to test. I'm also an idiot, as it took me an hour (and help) to realise that I was using the wrong com port earlier today, so it might be something that dumb.
posted by jacalata to Computers & Internet (6 answers total) 1 user marked this as a favorite
 
I don't know thing one about the specific equipment you're using, but when similar stuff has given me similar trouble, the option to completely erase the chip has been helpful.
posted by TheOnlyCoolTim at 7:25 PM on April 2, 2006


Is the chip concerned the one that came with the STK500? If so, did it run its LED toggling demo routine when you first powered it up?
posted by flabdablet at 11:09 PM on April 2, 2006


Response by poster: No, the chip didn't come with the stk500. The board is provided by the university, and we've bought the chip for an assignment (paid for by uni). Today is the first time I've powered it all up, and nothing happened.

I posted the question at avrfreaks as well, and they've suggested that I've wired it up wrong (in a cross between the ISP and high voltage instructions), so tomorrow I'll head back to the lab and check that out.
posted by jacalata at 4:36 AM on April 3, 2006


I don't know the AVRs that well, but besides a miswire, which is possible, check the voltage on the program enable pin. If they're like the PICs in HVP mode, you need that voltage to be high enough with some current, and a common error in the HVP days was to have +16V when it was floating, but when you start programming, the current draw would pull the voltage down enough to cause the PIC to drop out of program mode.

Ideally, of course, you have a regulated supply providing Vpp, but most people didn't, and just used a wall wart. A +12V 1A wall wart would often provide +16V 50mA, but sometimes, it didn't, and a +12V 250mA wart almost never would.

I'll look at the specsheet later and see how they program, but since you already have one (right?), if you are wired correctly, check that.
posted by eriko at 5:43 AM on April 3, 2006


http://students.washington.edu/nwk/STK500_sample_program/STK500_sample_program.html

From there, make sure you can read the configuration fuses from AVR Studio, and set them properly. Every AVR device I've worked with is by default configured to use a slow internal RC oscillator, so set the proper fuses to select the desired oscillator.
posted by lalas at 1:03 PM on April 3, 2006


Response by poster: I had it wired wrong, but thanks for the suggestions!
posted by jacalata at 11:36 PM on April 4, 2006


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