Arduino pro mini (clone) @1Mhz target does not answer Recently I have been experimenting with battery powered sensor (mySensors).

I created node with 3.3V Arduino Pro Mini (ATMega328P @ 8Mhz with nordic radio chip and BME280 sensor) and successfully programed it many times using either USBAsp programmer or serial (to USB) programmer.

I wanted to lower power consumption and so I disconnected power led and burned fuses as follows:
lfuse 62
hfuse DA
efuse 7

It worked successfully and I recompiled the sketch and upload it with USBasp.
I got an error that data cant be verified. It was late in the night so I jumped to Internet and googled it. In one forum I found, post (which I am unable to find again) that stated the he was able to upload sketch when he switched programmer to 5V. (Power was connected to Vcc)

I did that and it worked fine.

Than I tried to make change to sketch and upload it again (on 3,3V) and again got verification error so I unplugged programmer and switched back to 5V.

When I did that, the device stopped answering.

I regularly used this command to check that device responds and see fuses

avrdude.exe -C"C:\Program Files (x86)\Arduino\hardware\tools\avr/etc/avrdude.conf" -v -patmega328p -cusbasp -Pusb


What i did


Checked wiring.
Tried program fuses on blank new arduino - worked (programmer is
fine)
Measured voltage ok
Measured current (its around 4mA, I see it as the board is not
sleeping and is actively doing something)
I noticed that when I issue command mentioned above the on board led
quickly lights up and then goes off again.
I tried to power it from raw, from Vcc and from Vcc on serial hader (picture).
I measured power on Vcc when connected to Raw pin and it reads 3.3V
so power regulator should be ok.
I used -B10 switch to averdude with no luck


My question is


Is it possible that I burned the ATMega chip?
Is it possible that I see target not answering because of USBAsp is unable to lower programming frequency? (warning: cannot set sck period. please check for usbasp firmware update.)


Please suggest if there is anything I can try before throwing it out.

Thank you.




EDIT 2017-01-07
I was able to brick another board.
I think that the programmer is the cause.

I tried to upload bootloader with fuses from arduino and it failed with verification error.

I was able to burn bootloader from command line after seting fuses and restarting the board.

When I tried to upload the program it I got 

avrdude: verifying ...
avrdude: verification error, first mismatch at byte 0x0000
         0x00 != 0x0c
avrdude: verification error; content mismatch

avrdude: safemode: lfuse reads as 0
avrdude: safemode: hfuse reads as 0
avrdude: safemode: efuse reads as 0
avrdude: safemode: lfuse changed! Was 62, and is now 0
Would you like this fuse to be changed back? [y/n] n
avrdude: safemode: hfuse changed! Was da, and is now 0
Would you like this fuse to be changed back? [y/n] n
avrdude: safemode: efuse changed! Was 7, and is now 0
Would you like this fuse to be changed back? [y/n] n
avrdude: safemode: Fuses OK (H:07, E:DA, L:62)


I answered yes because in in earlier attempts it just froze.

Now the board is in same condition as the first one.

Is it possible to revive it?
Thanks.
I am closing this thread.

The board is probably not destroyed, more likely are fused corrupted.
There are ways of reviving ATMega328 chip and program fuses back its called high voltage programming. You need to probably unsolder the chip or modify your board (post from tontrack).

Also if you are wondering what to do or not to your Arduino board here is quite interesting page (you wil find it in comment).

I did not found a way how it could have happen but it did.

Anyway Iam done with UsbAsp programmer and ordered AVR pocket programmer. Until it arrives I stop any more attempts.

Hope this helps somebody.