External SPI SRAM

Use more memory, with MAKERbuino.

Note: Program area and built-in SRAM will not increase. Note that it is an external storage device.

Install the SRAM in the space behind the LCD screen.

It fits perfectly when using SMT.

Parts

• • SPI SRAM , 23LCV512-I/SN 64Kbyte SOIC package.

  • PCB Board for pitch conversion ( for Breakout ) like this.

  • Wire

Wiring

Connect SRAM and ATMega328.

1 : -> D5

2 : -> MISO

3 : N/C

4 : -> GND

5 : -> MOSI

6 : -> SCK

7 : -> 100kohm -> 8

8 : -> VCC

Added circuit (30. December. 2017)

and, VCC -> R -> 1

This is a pull up resistor for CS.

It prevents SPI SRAM reading and writing when D5 is HighZ, so it will pull up to prevent it.

I used 47KΩ for resistance.

On the back side of the chip ... it looks like this.

In the photograph, the first pin of SRAM is in the lower right.

Enlarged picture of the back side of ATMega.

Orange : D5

Red: VCC

Black: GND

Gray: SPI. From above SCK. MISO, MOSI.

and additional circuit. (30. December. 2017)

1:CS -> R (47K ohm) -> 8:VCC

Library

• • simple SPI SRAM access Library for Makerbuino SRAM mod. (github)

More Information

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