Test Arduino to Arduino Communications

[ChrisTClark]

Testing directly linked communications between two Arduino Uno R3's

Reference

• https://www.instructables.com/Communicating-With-Two-Arduinos/
• https://www.arduino.cc/en/Tutorial/BuiltInExamples/Button

[ChrisTClark]

Step 1: Test simple pushbutton to internal LED. Status: Successful

Reference: https://www.arduino.cc/en/Tutorial/BuiltInExamples/Button This Board was COM6 for an Arduino Uno R3

Turns on and off a light emitting diode(LED) connected to digital pin 13, when pressing a pushbutton attached to pin 2.

The circuit:

• LED attached from pin 13 to ground

• pushbutton attached to pin 2 from +5V

• 10K resistor attached to pin 2 from ground

• Note: on most Arduinos there is already an LED on the board attached to pin 13.

  created 2005 by DojoDave http://www.0j0.org modified 30 Aug 2011 by Tom Igoe

  This example code is in the public domain.

  http://www.arduino.cc/en/Tutorial/Button */

// constants won't change. They're used here to set pin numbers: const int buttonPin = 2; // the number of the pushbutton pin const int ledPin = 13; // the number of the LED pin

// variables will change: int buttonState = 0; // variable for reading the pushbutton status

void setup() { // initialize the LED pin as an output: pinMode(ledPin, OUTPUT); // initialize the pushbutton pin as an input: pinMode(buttonPin, INPUT); }

void loop() { // read the state of the pushbutton value: buttonState = digitalRead(buttonPin);

// check if the pushbutton is pressed. If it is, the buttonState is HIGH: if (buttonState == HIGH) { // turn LED on: digitalWrite(ledPin, HIGH); } else { // turn LED off: digitalWrite(ledPin, LOW); } }

[ChrisTClark]

Step 2: Test simple pushbutton to external LED Status: Successful

Sketch Feb27b

Reference:

• Step 1
• https://create.arduino.cc/projecthub/krivanja/working-with-an-led-and-a-push-button-71d8c1

This Board was COM6 for an Arduino Uno R3

Turns on and off an external LED when pressing a pushbutton attached to pin 2.

//COM 6 Arduino Uno R3

// constants won't change. They're used here to set pin numbers:

const int buttonPin = 2; // the number of the pushbutton pin const int LED = 3; // the number of the LED pin

// variables will change:

int buttonState = 0; // variable for reading the pushbutton status

void setup() { // initialize the LED pin as an output: pinMode(LED, OUTPUT); // initialize the pushbutton pin as an input: pinMode(buttonPin, INPUT); }

void loop() { // read the state of the pushbutton value: buttonState = digitalRead(buttonPin);

// check if the pushbutton is pressed. If it is, the buttonState is HIGH: if (buttonState == HIGH) { // turn LED on: digitalWrite(LED, HIGH); } else { // turn LED off: digitalWrite(LED, LOW); } }

[ChrisTClark]

Step 3: Write code for Master Arduino, pushbutton as output to another Arduino

Key: cannot test I2C really, unless both units tied together, code will not run and will stop on the wire begin...

Notes

• We are essentially building an I2C bus
• Last code for Master: Mar24a_Master
• Last code for Slave: Mar23a Slave

Reference

• https://www.instructables.com/I2C-between-Arduinos/
• https://www.arduino.cc/en/Tutorial/LibraryExamples/MasterWriter (this one is essential)
• https://circuitdigest.com/microcontroller-projects/arduino-i2c-tutorial-communication-between-two-arduino