Connect with us

Hi, what are you looking for?

Tweaks

Here Is The Mystery Of A Particular ATiny85 Fuse

First-timers playing with 8-bit micros such as the AVR and PIC will at some point in their lives, find themselves locked out of their MCUs. This is usually attributed to badly configured fuses that disable certain IO functions rending the device unprogrammable via conventional ICSP methods. [Uri Shaked] shares his story of how his ATtiny85 got locked and became the subject of a lengthy investigation into fuse bit configurations.

[Uri]’s journey started when he accidentally left some pins of the device connected to a second board while he was flashing the firmware. He quickly researched online for a solution for the problem and it turns out, there is a page[External Link] on a number of recipes on how to resolve the issue. As it turns out, his problem was not so straight-forward and warranted more digging. [Uri] ended setting up a High Voltage Programming serial programming setup and then probing the communications. He discovered that the chip refused to reset its fuses and would reject attempts to set fuses.

Further investigation of the fuse bits and reading them proved useful in understanding that the memory protection features were preventing alteration of the device. The quick-fix was to erase the attiny and things were back to normal thereafter. [Uri] details his pursuit of reading and comparing fuse bits from the impacted chip against a fresh device which is where he makes the discovery. The write-up is a case study in the investigation into the Idiosyncrasies of device programming and will be a great resource for many and reduce hair loss(self pulled hair in frustration) for some.

Once you get your hands on an ATTINY, there are a number of small experiments to be done to cure boredom. Be sure to share your experiments and stories with us to inspire the masses.

Image Source: Hackaday


Advertisement. Scroll to continue reading.
AIAD

You May Also Like

Tweaks

It’s common knowledge that Windows XP won’t run on a 386, or Windows 95 on an original IBM PC. However, with the latest releases...

Tweaks

Apple previously supported a “Right to Repair” bill in California but is now opposing a similar bill (Senate Bill 1596) in Oregon due to...

Tweaks

San Francisco is fighting to stop self-driving cars and taxis from operating in the city. Despite getting the green light from the authorities, the...

Tweaks

Back in April 2023, Microsoft had announced they would stop selling their own branded peripherals such as keyboards and mice to focus on Surface...