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Calcwriter logic

kaemori·calcwriter_blueprint·calcwriter_logic/calcwriter_logic.kicad_pcb

Calcwriter logic PCB layout, top view — open source AVR/Arduino board by kaemori

About the Calcwriter logic PCB

Calcwriter logic is an open source AVR/Arduino PCB design by kaemori, published on GitHub under the MIT license. It is a 2-layer board measuring 27.3 × 37.3 mm, with 33 components from 21 distinct parts.

Its main chip is the ATmega32U4-MU, from the AVR/Arduino family. Other key parts include the ME6211C15M5G-N and SN74LV4051ADR. By type, the board carries 4 ICs, 3 LEDs, 2 connectors and 1 crystal.

It belongs with the science & space designs in this gallery.

From the project

An external board that emulates inputs to the keypad matrix of a Sharp EL-W531S II Scientific Calculator.

A hardware board that emulates keypresses on the keypad matrix of a Sharp EL-W531S II calculator.

So uh, once upon a bus ride home, I had a brain blast — a year before, I made math equations that mimicked computer logic ops like AND, OR, NOT, etc. Then I got spicy and added stuff like SIGN, TOBOOL, and EQUALSTO. I even hacked together if statements and pseudo-loops! but... I couldn’t store variables (tragic).

Calcwriter logic, from the project README
From the project README

Main components on the Calcwriter logic

ATmega32U4-MUME6211C15M5G-NSN74LV4051ADR

Calcwriter logic bill of materials (BOM)

33 components, 21 distinct parts — part numbers from the project's BOM.

QtyPartRefs
1
ATmega32U4-MU
U1
1
ME6211C15M5G-N
U2
2
SN74LV4051ADR
U3, U4
1
16MHz
Y1
1
FH12-40S-0.5SH_55_
CON1
1
USB_C_Receptacle_USB2.0_14P
J1
7
100nF
AREF_C1, MUX_C1, MUX_C2, PWR_C2, VCC_C1, VCC_C2, VCC_C3
2
10uF
CALC_PWR_C1, PWR_C1
1
22uF
CALC_PWR_C2
1
10k
CALC_PWR_R1
1
330
CALC_PWR_R2
2
280
LED_R1, LED_R2
2
30pF
OSC_C1, OSC_C2
1
1k
OSC_R1
2
5.1k
PWR_R1, PWR_R2
1
10k
RST_PU1
2
22
TERM_R1, TERM_R2
1
1uF
UCAP_C1
1
LED_GREEN
ACT1
1
LED_RED
CALC_PWR_D1
Show 1 more
QtyPartRefs
1
LED_YELLOW
STALL1

Calcwriter logic design files

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

Calcwriter logic: common questions

What microcontroller does the Calcwriter logic use?

The Calcwriter logic is built around the ATmega32U4-MU, from the AVR/Arduino family.

How big is the Calcwriter logic PCB?

The Calcwriter logic measures 27.3 × 37.3 mm, has 2 copper layers and is 1.6 mm thick.

How many components are on the Calcwriter logic?

33 components, from 21 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 Calcwriter logic design files?

From the kaemori/calcwriter_blueprint 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 Calcwriter logic design in my own project?

Yes, under the terms of its MIT license, which kaemori chose for the repository.

Can I test firmware for the Calcwriter logic 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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