programming an attiny

[pratto]

all the questions i saw regarding attiny's addressed operating issues. nobody but me seems to not be able to get it to work at all.
my arduino 1.0.1 works fine with my computer serial link, using arduino uno as the board. the example blink sketch blinks fine, as do other little programs i have written.
but when i try to program my attiny85 to do anything, it doesn't work.

i followed 3 or 4 sets of web instructions, including the youtube shrinkify video, but no luck.

here is what i have been doing, with comments.
a little help getting me going would be much appreciated.

1-plug in my uno board to the usb.
2- open the arduino p.env.
3- open example, arduino ISP
4- select board: arduino uno
5- upload arduino ISP sketch to the UNO board.  loads without any issues.
6- close arduino ISP sketch. usb is still plugged in.
7- wire attiny85 per "shrinkify video" attiny 1:Uno 10  ; att 4:U grd ;  att 5:U 11 ; att 6: U 12 ;  att 7: U 13 ; att 8: U  +5v;  10 microf cap reset to grd (neg side cap to grd).  the usb is still plugged in.
8- open example blink sketch.
9- in sketch change pin 13 to pin 3.
10- select board : "attiny 85 (internal 20 Mhz clock)".  the option shown in the video "attiny85 w/ arduino as ISP" is not available. in the lower right it says "ATtiny85(internal 8 MHz clock) on com3".
11- upload sketch. get error "avrdude: usbdev_open() : did not find any USB device "usb"".

if i plug in an led from atttiny pin 3 to ground, nothing.

i don't think it is working.  i haven't fried my arduino, because if i dis-connect the attiny and the cap, and select arduino UNO board, it still runs the blink program just fine.

[dhenry]

a little help getting me going would be much appreciated.

Download AS5.0 and get a $5 avr programmer and start coding.

[pratto]

anyone else have a suggestion ?

[pratto]

after 1-2 more hours of fiddling around, i'm not sure what i have done, but it seems to be working. the delay lasts 8 times as long as i expected, but when i change to attiny85 1 MHz internal, the delay is right. i'll have to give this some thought.

now comes the anxiety of taking it apart and trying to re-assemble it (not knowing what i did to make it work).

[nickgammon]

You probably have the "divide clock by 8" fuse bit set. I think that is the factory standard.

[Arrch]

after 1-2 more hours of fiddling around, i'm not sure what i have done, but it seems to be working. the delay lasts 8 times as long as i expected, but when i change to attiny85 1 MHz internal, the delay is right. i'll have to give this some thought.

now comes the anxiety of taking it apart and trying to re-assemble it (not knowing what i did to make it work).

Before programming for the first time, select Tools > Burn Bootloader; it will set the fuse bits properly.

[pratto]

ok. got it apart and back together, and hey presto, it didn't work. but after more hours of fiddling around, and starting from scratch with the MIT high-low tech instructions, it is working again. i think loading the arduinoISP to the UNO board again did the trick.

thanks for the comments.

[Riva]

Once you have uploaded the ArduinoISP sketch to your UNO you would be safer/better to unplug it from the USB/power while wiring up the ATtiny and putting the reset capacitor on, then re-connect the USB.
As Arrch said the very first time you try to program a new ATtiny you need to select it's type in Board and then do burn bootloader. This will not actually burn a bootloader but will set the fuses correctly so when you load/compile your tiny sketch and 'upload using programmer' it should work with just two warning messages you can ignore.