Shlepok

ATMEGA328 compatible program that have:

Simple calculator with float results support

.TXT text reader from SD card

Program features:

Scrolling in long text files

Only 3 buttons need to use device.

Uses 22KB Flash and 1.5KB RAM.

Uses I²C 128x64 monochrome OLED display.

Pins (if on bare chip):

If on Arduino plate, then skip power pins.

Power:

VCC - AVCC
GND - AGND
VCC - 10k - RESET

SD:

D9 - CS (Chip Select)
D11 - MOSI
D12- MISO
D13 - SD clock (SCK)

Buttons:

D5 - BTN UP
D6 - BTN DOWN
D7 - BTN SET

OLED:

A5 - SCL
A4 - SDA

Thanks to @AlexGyver