Chip Program Enable Error (progisp)

Using Arduino IDE 1.x
1

Hello all,

I downloaded a code to Atmega328p using progisp using the following fuse bits.

Fuse bits: 0xFDD9FF where the low fuse bits are 0xFF, high fuse bits are 0xD9 and Ext. fuse bits are 0xFD. It works fine.

Later i thought of using the internal oscillator and for that i changed the fuse bits as following.

Fuse bits: 0xFDD973 where the low fuse bits are 0x73, high fuse bits are 0xD9 and Ext. fuse bits are 0xFD. It flashed and threw a flash verify error and since then, it is showing chip program enable error. How should I proceed?

Any help is greatly appreciated!

Thanks and Regards,
Akhil Pillai

2

Hello? No one has encountered this before?

3

akhil007:
low fuse bits are 0x73

This is "Undefined Preset 7":

How did you come up with this low fuse value?

The confusing thing about fuse bits is that programmed = 0 and unprogrammed = 1. I'd guess you ended up accidentally inverting all the bits from what you had intended (0x8c) but that's for an external crystal, so maybe not.

4

Hello,

What should be the fuse bits if I want to use the internal oscillator?

5

E2 for low fuses

I suspect the chip has been soft-bricked at this point, suspect you would need to use HVSP to restore it so you could program it again.

6

E2 for low fuses and the high and extended fuse bits remain the same? i.e 0xD9 and 0xFD. I have isp programmer, can it not be restored using isp?

7

According to the datasheet 0x73 selects the 128kHz oscillator and the divide by 8 fuse so your avr is running at 16kHz. Try adding -B 4kHz to the avrdude command line.

8

Actually i flashed it using progisp. So I am not sure how to do this using progisp? Is it necessary to use AVRDUDES to restore it?

9

Well you need to set the spi clock speed to about 1/4 the clock speed of the avr. How you do that with progisp I have no idea.

10