The Start

Hi, What and Why

Plug it in

Rule number 1

Water Sensor

Sound Sensor


Tri Colour LED

RTC (Real Time Clock) DS1302

RTC (Real Time Clock) DS3231

Matrix LED step 1


Stepper Motor

LCD revisited with PCF8574T

Humidity Sensor

Shift Register

RFID tags (RC-522)

7 Segment display

Ultrasonic distance sensor

5V regulator

analogRead and analogWrite

Wiring an Array of Switches

The next step

Other things I have bought

Infra red and Processing

Programming a separate arduino chip

Creating your own PCB

L293D for a DC motor

4 digit 7 segment display

Starting with motors

RF433 Wireless Comms

Sort a character array

More stuff

I2C devices (SDA,SCL)

I2C scanner

SPI devices (MOSI,MISO)

HMC5883L Compass

MMA7361 Accelerometer

Added projects

Message Display System

4WD robot car
4WD robot car II

4WD robot car COMPLETE

MP3 Player

SPI devices - example: 23K256 SRAM memory chip

If something has connectors labelled MOSI and MISO, then it is an SPI device that can be accessed using the SPI.h library.
Arduino Uno :
MOSI goes to pin 11
MISO goes to pin 12
SCK goes to pin 13
CS - Chip Select - nominally the first device is connected to pin 10; but any pin can be used, and to connect multiple SPI devices, each device needs it's own CS pin.

When a device's CS pin is low, it can communicate.
When it's high, it ignores all communications. This allows you to have multiple SPI devices sharing the same MISO, MOSI, and CLK lines.

As an example, I'm using the SRAM memory chip 23K256 that I ordered last week.

This is an SPI device; the chip 23K256. That's 256 KILO-BITS. There are 8 bits in a byte; so you have to divide that by 8, to get the size more commonly used - 32 Kb. SPI devices

There is a library given in the arduino playground called spiRAM. However, it's got a couple of versions and all agree that it's incomplete and should be updated when someone can find the time.
I will look at the library code, see how the chip works and how the software works, and generally investigate.

Other libraries :

This is perhaps an unusual chip to demonstrate the SPI interface; but I need to use it my mp3 player project.