Blank Chips not programming

I have got a board similar to the boot cloner Arduino Playground - HomePage to flash the boot loader into blank chips.
I bought a tube of 14 168 chips (from Farnell) and proceeded to flash them.
However out of the 14, four would not program up, they failed to erase the flash.
Does any one know if blank chips sometimes require high voltage programming to erase the flash?

Hi,

Does any one know if blank chips sometimes require high voltage programming to erase the flash?

I don't think so. I burned the bootloader with my avrisp mk2 on 10 blank 328p without any failure.

Eberhard

Hope the chips aren't bad. Its unlikely but could happen.

I had a similar problem. Working setup. Flashed 100 parts no problem. Next tube
of parts wouldn't flash.

After changing the avrdude bitclock switch to -B 10 or -B 100 the chips flashed. I believe that some chips may come from the factory with different fuse settings but I have not verified this. The next time I get a large batch of chips that won't program I am going to get a better solution. It hasn't been enough of a PITA to bother with :wink:
Yet :wink:

(* jcl *)

I believe that in order to be ISP programmed, the chips have to have a clock signal, which normally means that they need to have the fuse bits set to use the internal clock. I have heard that for one reason or another, this is not always the case...

I believe that in order to be ISP programmed, the chips have to have a clock signal, which normally means that they need to have the fuse bits set to use the internal clock.

I think you are correct. A clock source is required. If the fuses are set to internal
clock you always have a clock. If not you have to provide one.

I have heard that for one reason or another, this is not always the case...

Actually this may help explain my problem. My setup has a 12MHz external
crystal which should work with all bitclock settings. I am not sure what the internal clock defaults to but if it requires a bit clock greater than 1uS then that
could explain why -B 10 works. If not then nevermind :wink:

If you ever find out the one reason or the other one please post it :wink:

Thanks for the info.

(* jcl *)

I am not sure what the internal clock defaults to

The 328 and 168 I have both came with the fuses set to 8MHz Internal Oscillator, Divide Clock by 8. I can't remember where I read it (datasheet, AVR Freaks, internet at large) but I believe this is how the processors are supposed to leave the factory.

I've been using the Pololu programmer without any problems. But my sample size is kind of small.

Thanks guys, I do have a 16MHz crystal on the boot cloner, I will check out the fuses on the ones that won't program.