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Discussions on the software and hardware for Atmel's STK standard.
By daduhaime
#181148
As per ATMEL pin configuration for an attiny85
from pin 1 to 8 are listed as
Chip pin # 1 - PB5
Chip pin # 2 - PB3
Chip pin # 3 - PB4
Chip pin # 4 - GND
Chip pin # 5 - PB0
Chip pin # 6 - PB1
Chip pin # 7 - PB2
Chip pin # 8 - VCC

As per Sparkfun electronics attiny85 Arduino Quick reference sheet,
you can use pin 0 to 4 for general purpose I/O pins
0 = Chip pin # 5
1 = Chip pin # 6
2 = Chip pin # 7
3 = Chip pin # 2
4 = Chip pin # 3

my question is this one, is it possible using the Attiny85 AVR Programmer to have access to chip pin # 1,
and if so how do you access-it

I try the following
pinmode(5,output)
and try to write a value in that port of high or low,
the software upload without any problem, but the chip dye, and nothing happens annymore

Am I using the proper syntax ?
Otherwise what is required in order for me to use this pin # 1 of the Attiny85

I need 1 extra output, could be digital or analog.

Otherwise it seems like I might have to use attiny84 instead.

Thanks
By Valen
#181155
In order to use pin PB5, which is the reset pin, you need to program it with specific fuse settings. And because you cannot reset it anymore you need a special high voltage programmer. The ICSP method of programming won't work. And the regular arduino bootloader neither, for sure. Here is a tutorial/guide that explains more about it:

http://projectsfromtech.blogspot.nl/201 ... y8545.html

p.s. maybe there is a clever way to reduce your pin usage and free one up for another use.
By stellajohn
#191520
Valen wrote:In order to use pin PB5, which is the reset pin, you need to program it with specific fuse settings. And because you cannot reset it anymore you need a special high voltage programmer. The ICSP method of programming won't work. And the regular arduino bootloader neither, for sure. Here is a tutorial/guide that explains more about it:

http://projectsfromtech.blogspot.nl/201 ... y8545.html

p.s. maybe there is a clever way to reduce your pin usage and free one up for another use.
Thank you for the best link :)