Attiny85 pin 1

Discussions on the software and hardware for Atmel's STK standard.

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daduhaime
Posts: 5
Joined: Thu Mar 26, 2015 8:01 pm

Attiny85 pin 1

Post by daduhaime » Sun Apr 12, 2015 8:21 pm

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

Valen
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Posts: 1743
Joined: Wed Dec 22, 2010 2:05 am

Re: Attiny85 pin 1

Post by Valen » Mon Apr 13, 2015 4:28 am

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.

stellajohn
Posts: 13
Joined: Sat Aug 20, 2016 12:15 am

Re: Attiny85 pin 1

Post by stellajohn » Fri Sep 02, 2016 11:29 am

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 :)

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