HOW TO INCREASE MULTIPLE SPI SLAVES OVER ONE ARDUINO

Hii All,
anyone knows how to increment sleve devices over one ardunio?..I want 22 slave devices connected to the arduino...but Unfortunately i dont have that much pins available on arduino :confused: kindly help..Thank You :slight_smile:

Use a Mega ?

With that many devices the extra SRAM may also come in handy?

...R

I am using Arduino Nano...and how to use Extra SRAM ???

akshay123:
Hii All,
anyone knows how to increment sleve devices over one ardunio?..I want 22 slave devices connected to the arduino…but Unfortunately i dont have that much pins available on arduino :confused: kindly help…Thank You :slight_smile:

What about using an Arduino board with more I/O pins, like MEGA2560?

A MEGA2560 also provides more RAM than a NANO, so this possibly also helps you with the problem “lack of RAM while using many SPI devices”.

Okay..sorry i am new to the arduino...how that SRAM should be used to drive 22 slaves?please give directions... :slight_smile:

You need more IO pins, not necessarily more SRAM.
Sounds like a board with Atmega1284P would fit your needs.
It has 32 IO, so keeping 2 pins for serial, and SCK-MISO-MOSI for SPI, leaves 27 pins for chip selects.
And it has 16K SRAM if your sketch happens to need that.
I offer boards in several form factors.
http://www.crossroadsfencing.com/BobuinoRev17/




With RTC, SD card, RS232 buffer option for 2nd serial port, onboard or offboard USB/Serial adapter, and with or without screw terminals:

akshay123:
Okay..sorry i am new to the arduino...how that SRAM should be used to drive 22 slaves?please give directions... :slight_smile:

The SRAM is not necessarily needed. However I assumed that if you are trying to communicate with 22 devices your code and your need to store data would be greater than if you are communicating with 2 devices.

...R

We don't know your application or speed requirements, but maybe consider a daisy chained configuration (only 4 pins required).

Thanks alot all of you :slight_smile: