Simultaneously Reading Multiple Analog Inputs from Two Different Arduino UNOs

Reading multiple analog inputs from two different Arduino UNOs simultaneously is often required in many projects, whether it is for sensing environmental data or controlling complex systems. This guide covers two methods to achieve this: Serial Communication and I2C Communication. Each method has its advantages and is suited to different scenarios.

Method 1: Using Serial Communication

Serial Communication is a straightforward approach that involves setting up two Arduinos to send and receive data over their serial ports. Here's a detailed explanation of how to set this up.

Setup the Hardware

Connect the two Arduino UNOs to your computer via USB. Connect the analog sensors to the appropriate analog pins on each Arduino.

The hardware setup ensures that both Arduinos can communicate with the computer. Next, we will write the necessary code on each Arduino.

Arduino Code

Arduino 1 Code:

![CDATA[void setup {
tpinMode(9600, Serial);
}

![CDATA[void loop {
tint sensorValue1  analogRead(A0);
tint sensorValue2  analogRead(A1);
}

Arduino 2 Code:

![CDATA[void setup {
tpinMode(9600, Serial);
}

![CDATA[void loop {
tint sensorValue1  analogRead(A0);
tint sensorValue2  analogRead(A1);
}

Read Data on the Computer

To read data from both Arduinos, you can use a program such as Python Processing or the Arduino IDE's Serial Monitor. In this example, we will demonstrate how to use Python with the pyserial library to read data from both ports simultaneously.

![CDATA[import serial
import time

# Adjust the port names as necessary

arduino1  ('COM3', 9600)
Change COM3 to your Arduino 1 port

arduino2  ('COM4', 9600)
Change COM4 to your Arduino 2 port

while True:
tif () > 0:
ttdata1  ().decode('utf-8').strip()
ttprint(data1)
tif () > 0:
ttdata2  ().decode('utf-8').strip()
ttprint(data2)

(2)

]]

Method 2: Using I2C Communication

I2C Communication is more integrated, allowing for a more efficient communication protocol without managing multiple serial connections. This method is ideal for scenarios where you need to add more devices in the future.

Setup the Hardware

Connect the two Arduino boards using the I2C protocol. Connect the SDA pins together and the SCL pins together along with a common ground.

For the I2C setup, one Arduino is designated as the master, and the other as the slave.

Arduino Code

Master Arduino Code:

![CDATA[include Wire.h

void setup {
();
t// Join I2C bus as master
(8);
tWire.write(4);
tWire.endTransmission();
t9600;
}

![CDATA[void loop {
tbyte request  (8, 4);
t// Wait until the slave has sent all data
twhile(Wire.available()) {
ttchar c  ;
ttc;
t} // Read all 4 bytes back
t// Process the data (if necessary)
t// High delay to prevent rapid data transmission
tdelay(100);
t}

]]

Slave Arduino Code:

![CDATA[include Wire.h

void setup {
(8);
tWire.onRequest(requestEvent);
}

![CDATA[void loop {}

void requestEvent() {
tint sensorValue1  analogRead(A0);
tint sensorValue2  analogRead(A1);
tWire.write(sensorValue1);
tWire.write(0b10000000);
tWire.write(sensorValue2);
tWire.write(0b10000000);
}

Summary

Serial Communication is simpler to set up and allows you to read data from each Arduino independently. You can process the data on your computer. I2C Communication is more efficient for integrated systems and allows for easier scaling if you want to add more devices in the future.

Choose the method that best suits your project requirements!