Lock bits

Hello!

I accidentally set all the lock bits to 1,
as soon as i set wrote the bits, ponyprog gave the message "Device Missing".
it gave same error when i tried to read or write flash program.

I want to ask is there any thing which can be done so that the AVR can be programmed again ?
And what are the recommended Fuse bits and lock bits settings for a learner ?

i think there is no other way than High Voltage Parallel Programming.

if u r not sure, dont try to modify the fuse bits, specially the lock bits.

there is an interesting site ----
http://palmavr.sourceforge.net/cgi-bin/fc.cgi?P_PREV=&P=ATmega32
this can help u to decide the fuse bit setting.

also u can read this ---
http://www.scienceprog.com/programming-avr-fuse-bits-oscillator-settings/

thanks rahul :-)

but now i have a real problem, i unselected all the lock bits(which are default).
still after writing the fuze bits, pony prog gave the error "Device Missing (-24)". and no futher reading proggramming can be done.

Please help me in this regard, i dont want any locks, i just want to run simple programs on the avr for learning using the external oscillator.

once locked, there is only one way --- High Voltage Parallel Programming.

i think your microcontroller can be detected now unless u use above methode. i heard it is very difficult to build such programmer.

i found one if you are intrested ---

http://elm-chan.org/works/avrx/report_e.html#AVRXP

thanks rahu :-)l

i have already locked 3 avrs, now i want to know exactly which bits in "security and configuration bits" to check/uncheck.
because i dont want to lock another one

please help

please correct my name.

also i dont even know much about the fuse bits. you can refer to the datasheet. it is a good piece of informaton.

Well sorry for the typing mistake, Rahul
Thanks anyways

ami,
attach ur configuration photo here. it seems it was not attached properly in the PM. I did not receive any attachments. use only the supported formats (like jpg,gif...) else the attachment will be deleted .the supported formats are shown below :-) the reply window.


P.S.: before writing the security /configuration bits on the AVR using Ponyprog, be absolutely sure that the existing security /configuration bits are read first by you.

hey amii
lock bits cam be programed anytime i mean even if you have locked ur controller that does not mean u cant reprogram it. lock bits are usually for code security not for re-programability. So try programing your controller again.. this time do not check the lock bits..

yes ajay,
there is no problem programming the lock bits but u have to be really careful while programming the other configuration bits. For example, if u program the RSTDISBLE
fuse of the ATmega8, then it would be impossible to program it using the ISP programmer again as the RST pin function is disabled (PC6 is asserted on that pin) which is required to be pulled low to enter ISP mode.
so, amicool, if u really want to change the fuse/cofiguration bits, do understand fully what the function of that fuse bit is being used. all the fuse bit/configuration bit functions are clearly explained in the respective AVR manuals.Do go through it before changing them. If u have any doubts then we are there to help.
Good luck.