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Svi728keyboardreset

arttu76·svi728keyboardreset·hardware/svi728reset.kicad_pcb

Svi728keyboardreset PCB layout, top view — open source AVR/Arduino board by arttu76
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About the Svi728keyboardreset PCB

Svi728keyboardreset is an open source AVR/Arduino PCB design by arttu76, published on GitHub. It is a 2-layer board measuring 48 × 42 mm, with 10 components from 6 distinct parts.

Its main chip is the ATtiny85-20PU, from the AVR/Arduino family. By type, the board carries 7 resistors, 1 IC, 1 connector and 1 capacitor.

It belongs with the keyboards and retro computing designs in this gallery.

From the project

Keyboard reset for Spectravideo MSX SVI-728

Adds a soft reset to the Spectravideo SVI-728 MSX1 home computer (which has no reset button): holding GRAPH + CODE + ESC for ~0.3 s fires a machine-wide reset (the ATtiny pulses power-on-reset transistor T4's base, so the cartridge slot — e.g. a Carnivore2 — resets too, exactly like power-on). An ATtiny85 reads the combo from the machine's own keyboard scan, and strobes the matrix itself only for rows the machine isn't scanning — so the combo works no matter what the running software does with the keyboard: games with their own scan routines that poll only the rows they need, programs that…

Svi728keyboardreset, from the project README
From the project README

Main components on the Svi728keyboardreset

ATtiny85-20PU

Svi728keyboardreset bill of materials (BOM)

10 components, 6 distinct parts — part numbers from the project's BOM.

QtyPartRefs
1
ATtiny85-20PU
Assmann WSW
U1
1
Wire pads
-
J1
1
C315C104K5R5TA
100n
Kemet
C1
3
MFR-25FBF52-100R
100R
Yageo
R1, R2, R3
2
MFR-25FBF52-1K
1k
Yageo
R4, R5
2
MFR-25FBF52-10K
10k
Yageo
R6, R7

Svi728keyboardreset design files

The KiCad project lives in the arttu76/svi728keyboardreset repository on GitHub; these links point at the commit this page was built from.

Svi728keyboardreset: common questions

What microcontroller does the Svi728keyboardreset use?

The Svi728keyboardreset is built around the ATtiny85-20PU, from the AVR/Arduino family.

How big is the Svi728keyboardreset PCB?

The Svi728keyboardreset measures 48 × 42 mm, has 2 copper layers and is 1.6 mm thick.

How many components are on the Svi728keyboardreset?

10 components, from 6 distinct parts, with part numbers taken from the project's own BOM. The full bill of materials is listed on this page.

Where can I download the Svi728keyboardreset design files?

From the arttu76/svi728keyboardreset repository on GitHub, which has the KiCad layout, the schematic and the BOM; the links under Design files point to each one.

Can I use the Svi728keyboardreset design in my own project?

The repository has no license, so all rights stay with arttu76. Use it as a reference, and ask the author before reusing the design.

Can I test firmware for the Svi728keyboardreset without the hardware?

Yes. HardLabs builds a simulation of the board from its netlist and BOM, so you can run and debug AVR/Arduino firmware against it before you order a PCB.

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