All About Circuits Forum  

Go Back   All About Circuits Forum > Software, Microcomputing, and Communications Forums > Embedded Systems and Microcontrollers


Embedded Systems and Microcontrollers Discussion forum for projects and working with embedded systems and microcontrollers (FPGAs, PICs, AVRs). Get help with hardware issues and embedded programming.

Reply   Post New Thread
Thread Tools Display Modes
Old 12-15-2012, 12:48 PM
allahjane allahjane is offline
Join Date: Sep 2012
Posts: 75
Unhappy Locked ATMEGA8

hello there

I have a ATMEGA8 that I flashed with a AVR programmer. I think I messed up some of the Fuse bits unintentionally .

Now the the code I had flashed runs fine (without any external crystals) but I cannot re-flash (reprogram) the that microcontroller.
the programmer just refuses to identify anything is in its socket!

No, the programmer is okay as it can program other MCUs.

I am assuming I may disable the Serial programming interface of the MCU

If you think there could be some other problem please notify me.

is there anyway i can re-program the MCU to be used again?
Reply With Quote
Old 12-15-2012, 12:49 PM
MrChips's Avatar
MrChips MrChips is online now
Super Moderator
Join Date: Oct 2009
Posts: 9,300
Blog Entries: 24

The short answer is NO.
Most computer problems can be attributed to a simple problem - a loosewire behind the keyboard.

Reply With Quote
Old 12-16-2012, 01:45 AM
bug13 bug13 is offline
Senior Member
Join Date: Feb 2012
Location: The Hobbit Island (NZ), UTC +12
Posts: 801

Try high voltage programming, but if you don't have the high voltage programmer easily available, I would just buy another chip.

High voltage parallel
High voltage parallel programming (HVPP) is considered the "final resort" and may be the only way to fix AVR chips with bad fuse settings. Parallel programming may be faster and beneficial when programming many AVR devices for production use.

Zhuhua Wu, Electronics Engineering Student

The more I learn, the more I don't know.
Reply With Quote
Old 12-16-2012, 10:53 PM
hgmjr's Avatar
hgmjr hgmjr is offline
Super Moderator
Join Date: Jan 2005
Location: Tennessee, USA (GMT-6)
Posts: 9,030
Blog Entries: 11

I agree with bug13. I have experienced the occasional setting of a fuse that rendered the AVR that I was using to become temporarily unprogrammable. The high voltage parallel programming (HVPP) approach has always allowed me to recover.

Reply With Quote
Reply   Post New Thread

, , , , ,

Related Site Pages
Section Title
Worksheet Microcontroller principles
Worksheet Memory devices
Textbook Safe practices : Electrical Safety
Worksheet Digital display circuits
Worksheet Superposition theorem
Worksheet AC motor control circuits
Worksheet Oscilloscope trigger controls
Worksheet Overcurrent protection
Worksheet Arc flash and arc blast
Textbook Fuses : Physics Of Conductors And Insulators

Similar Threads
Thread Thread Starter Forum Replies Last Post
Video: Basics of Phase Locked Loop Circuits w2aew Electronics Resources 0 10-03-2012 09:52 PM
panasonic cordless locked???????????? aliashar86 General Electronics Chat 6 01-02-2010 11:08 PM

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

All times are GMT. The time now is 09:50 AM.

User-posted content, unless source quoted, is licensed under a Creative Commons Public Domain License.
Powered by vBulletin
Copyright ©2000 - 2014, vBulletin Solutions, Inc.