Instructions | ATTiny555

1
Flash the firmware
Download (or clone) the GitHub repository to a folder on your computer.

If you are building the original version, make sure to uncomment the following line at the top of ATTiny555.ino:
```
//#define AT555_ORIGINAL // comment out to use the original layout
```
Compile and upload the code to ATTiny85 using whatever programmer you like. For me, I used an UNO as an ISP.

Because code is in a .ino file, you need the Arduino IDE.
2

(Original version) Solder the backpack on

If you're building the original version of the project, take the 68KOhm resistor, shorten its leads, and use it to bridge the bottom two pins of the ATTiny85 (PB0 and GND), like so:

Make sure that the resistor bridges the two pins on opposite sides of the IC that are furthest from its orientation dot.
3

(Flip-chip version) Flip the chip

If you're building the flip-chip version of the project, take the chip and bend its leads backwards carefully. From my experience, they are prone to cracking at the base and breaking. I bent them against a flat surface, like a table edge.

Once the leads are bent backwards, use a wire to bridge pins PB0 and VCC.

You should end up with something like this:

That's it!
4

Enjoy your subpar 555 tImer

???

Check out this pinout diagram for reference:

Discussions

Titoxi wrote 12/16/2021 at 13:37

Interesting, especially if it can exceed the operating characteristics of a 555. For example, what is the maximum frequency at which it could oscillate?

Are you sure? yes | no

Shranav Palakurthi wrote 12/17/2021 at 06:01

This thing can't oscillate any higher than 10 kHz realistically, assuming you clock the ADC at 500 kHz like it is right now. However, with an ADC clock speed bump to something like 1 MHz, you could double that bandwidth to about 20 kHz, which still isn't good at all.

Are you sure? yes | no

Matthias Urlichs wrote 12/27/2021 at 13:00

No you cannot exceed the 555's speed. Quite the contrary.

The beauty of this hack is that you can add features. For instance I have this old setup where the 555 is used as a delayed-on-off controller (controllable with a bunch of potentiometers). I now need to also limit the total on-time. To do that I'd need another 555 with its assorted components … or I simply replace it with this hack.

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Shranav Palakurthi wrote 12/28/2021 at 00:30

Wow, I'm impressed that you've found a use for this project! I hope the documentation is detailed enough to help you get your idea working :D

Are you sure? yes | no

ATTiny555

Discussions

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