Reading EEPROM with programmer outputs wrong data

Other Hardware 3rd Party Boards
1

I'm having trouble reading EEPROM from ATTiny841 via avrdude and an AVR-ISP-MkII.

When I read the EEPROM using the programmer I get (I'll only give first 128 bytes):

3A 32 30 30 30 30 30 30 30 30 30 30 30 30 30 30
30 30 30 30 30 30 30 30 30 46 46 46 46 46 46 46
46 46 46 46 46 46 46 46 46 46 46 46 46 46 46 46
46 46 46 46 46 46 46 46 46 46 46 46 46 46 46 46
46 46 46 46 46 46 46 46 46 46 38 0D 0A 3A 32 30
30 30 32 30 30 30 46 46 46 46 46 46 46 46 46 46
46 46 46 46 46 46 46 46 46 46 46 46 46 46 46 46
46 46 46 46 46 46 46 46 46 46 46 46 46 46 46 46

If I write code for the micro to read the EEPROM internally and spit it out over UART I get:

00 00 00 00 00 00 00 00 FF FF FF FF FF FF FF FF FF
FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF

I'm confident that the UART output is correct as I specifically set the 8 bytes to 0x00 and the EEPROM was previously 'erased' to 0xFF.

I've tried the EEPROM programmer read with both the AVR-ISP and a USB-asp programmer and get the same results. The avrdude command I'm using is:

avrdude -C../etc/avrdude.conf -v -pattiny841 -cstk500v2 -Pusb -Ueeprom:r:eep.hex:i

I have previously written and read EEPROM in this way. The only thing I've done recently is upgrade my Arduino IDE to 1.8.12

Any ideas?

2

For USBasp try
-cUSBasp

or

-cAVRISP

for AVR-ISP.

3

It certainly ought to work...

Oh wait...

That output looks to be correct, but getting rendered wrong (it's the hex codes for the characters that represent that data, 0x30 is a 0, 0x46 is an F, 0x0D 0x0A is a CR LF newline

4

Great spotting @DrAzzy!

My (not so) trusty hex editor is the problem! That's quite an embarrassing mistake... but thank you very much for spotting it for me.

5

You are outputting in intel hex format, so it would be an ascii file, not binary.

-Ueeprom:r:eep.hex:i

if you want binary use -Ueeprom:r:eep.hex:r although I would not use the .hex file extension in that case.