[SOLVED] ATTiny85 IO pins all at HIGH

Other Hardware 3rd Party Boards
1

Hello, am new here, I am having difficulties getting my uploads to work, basically the simplest Blinky example, uploading to the attiny is fine however when i connect the LED, it does not blink, it stay HIGH all the time, in fact all pins light the LED. I have followed many tutorials online on getting arduino uno upload sketches via Arduino as ISP, am pretty sure with the connections, burnt bootloader, still to no avail. I have 5 ATTinys and all of them do the same, figured must be something with the Arduino IDE configuration or clock?

Attached below is the log, hoping this would help:

avrdude: Version 6.3-20171130
         Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
         Copyright (c) 2007-2014 Joerg Wunsch

         System wide configuration file is "/private/var/folders/0k/rbh27rc10sj3tljyw7vtkg4w0000gn/T/AppTranslocation/BBC1C726-9989-4EAE-815D-63797B2EB525/d/Arduino.app/Contents/Java/hardware/tools/avr/etc/avrdude.conf"
         User configuration file is "/Users/hosnibona/.avrduderc"
         User configuration file does not exist or is not a regular file, skipping

         Using Port                    : /dev/cu.wchusbserial1d1140
         Using Programmer              : arduino
         Overriding Baud Rate          : 19200
         AVR Part                      : ATtiny85
         Chip Erase delay              : 400000 us
         PAGEL                         : P00
         BS2                           : P00
         RESET disposition             : possible i/o
         RETRY pulse                   : SCK
         serial program mode           : yes
         parallel program mode         : yes
         Timeout                       : 200
         StabDelay                     : 100
         CmdexeDelay                   : 25
         SyncLoops                     : 32
         ByteDelay                     : 0
         PollIndex                     : 3
         PollValue                     : 0x53
         Memory Detail                 :

                                  Block Poll               Page                       Polled
           Memory Type Mode Delay Size  Indx Paged  Size   Size #Pages MinW  MaxW   ReadBack
           ----------- ---- ----- ----- ---- ------ ------ ---- ------ ----- ----- ---------
           eeprom        65    12     4    0 no        512    4      0  4000  4500 0xff 0xff
           flash         65     6    32    0 yes      8192   64    128 30000 30000 0xff 0xff
           signature      0     0     0    0 no          3    0      0     0     0 0x00 0x00
           lock           0     0     0    0 no          1    0      0  9000  9000 0x00 0x00
           lfuse          0     0     0    0 no          1    0      0  9000  9000 0x00 0x00
           hfuse          0     0     0    0 no          1    0      0  9000  9000 0x00 0x00
           efuse          0     0     0    0 no          1    0      0  9000  9000 0x00 0x00
           calibration    0     0     0    0 no          1    0      0     0     0 0x00 0x00

         Programmer Type : Arduino
         Description     : Arduino
         Hardware Version: 2
         Firmware Version: 1.18
         Topcard         : Unknown
         Vtarget         : 0.0 V
         Varef           : 0.0 V
         Oscillator      : Off
         SCK period      : 0.1 us

avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.03s

avrdude: Device signature = 0x1e930b (probably t85)
avrdude: NOTE: "flash" memory has been specified, an erase cycle will be performed
         To disable this feature, specify the -D option.
avrdude: erasing chip
avrdude: reading input file "/var/folders/0k/rbh27rc10sj3tljyw7vtkg4w0000gn/T/arduino_build_143315/Blink_attiny.ino.hex"
avrdude: writing flash (682 bytes):

Writing | ################################################## | 100% 1.45s

avrdude: 682 bytes of flash written
avrdude: verifying flash memory against /var/folders/0k/rbh27rc10sj3tljyw7vtkg4w0000gn/T/arduino_build_143315/Blink_attiny.ino.hex:
avrdude: load data flash data from input file /var/folders/0k/rbh27rc10sj3tljyw7vtkg4w0000gn/T/arduino_build_143315/Blink_attiny.ino.hex:
avrdude: input file /var/folders/0k/rbh27rc10sj3tljyw7vtkg4w0000gn/T/arduino_build_143315/Blink_attiny.ino.hex contains 682 bytes
avrdude: reading on-chip flash data:

Reading | ################################################## | 100% 0.94s

avrdude: verifying ...
avrdude: 682 bytes of flash verified

avrdude done.  Thank you.

Am using an Arduino Uno with latest Arduino IDE.


Note, i have gotten this to work the first time. Not sure why this is not working now.
I will try to upload picture or schematic if needed. Thanks guys

2

Your board is wired incorrectly. My guess is that the connection between ground pin on t85 and ground of the circuit board is not connected, but it is connected to the ground pin of the ISP header. Hence, ISP programming works. But when ISP programmer isn't connected, the chip is only connected to Vcc, so courtesy of the protection diodes, all pins are held at Vcc. Then you connect an LED between an I/O pin held at Vcc and the actual ground, and the actual ground, it goes on.

That's the only thing that immediately comes to mind that explains all the things you've seen

3

Hi, you were right! Connecting ground pin of my power supply directly to pin 4 of the AT85 worked for me. Not sure why connecting ground to ground rail of board does not work though,

thanks!

4

hosnibona:
Hi, you were right! Connecting ground pin of my power supply directly to pin 4 of the AT85 worked for me. Not sure why connecting ground to ground rail of board does not work though,

thanks!

Assuming the ground rail is connected to ground, and you've actually connected the ground pin of the IC to ground rail, it does. I suspect if you probe around with your multimeter, you'll find that one of those connections isn't.