Hello,
In my project, i have to use 2 or 3 accelerometers such as ADXL345 and connect them with one Arduino. However, i don't know it is possible. How can i overcome this situation?
The related wiring is for only one accelerometer.
http://www.rhydolabz.com/wiki/?p=1780
USE a MUX(Multiplexer) the ATmega328p already has a mux built in because it has various Analog inputs but just one A/D converter..... use a MUX , The only drawback is the time taken to read all the mux'ed analog inputs but it should be fine!
Sorry I thought its an Analog input one for i2c you need i2c port expander Arduino Playground - I2CPortExpander8574
Is that module you linked to, the exact module that you have ?
With the voltage regulator and those connection points ?
You want to use 2 or 3, but that makes a big difference.
Which Arduino board do you use ?
The ADXL345 can be use with SPI interface and I2C interface.
In I2C mode, only two of them can be used. Connecting that module to the Arduino board is no problem with most boards.
I don't know if there are libraries that support more sensors in I2C mode, but when a library is written well, you only have to create two classes and it should work.
In SPI mode you can use many of them, but you have to find a library that supports many of them. The SPI interface is also faster. But since it is a 3.3V chip, you might need extra hardware to connect it to a 5V Arduino board.
For example this module includes that extra hardware: ADXL345 - Triple-Axis Accelerometer (+-2g/4g/8g/16g) w/ I2C/SPI [STEMMA QT / Qwiic] : ID 1231 : $17.50 : Adafruit Industries, Unique & fun DIY electronics and kits
Maybe the OP can connect 2 on i2c and do not use any port expander and use SPI for another one if he needs 3 then he's fine and done.