Bussystems for the Arduino, ESP32 and other Microcontroller

With a system bus you can connect more sensors than without one, only using one on a pin.

Connect Arduinos over I2C(2019-11-12)

Connect Arduinos over I2C*(2019-11-12)

I2C-Master Sketch(2019-11-12)

```

include

define PAYLOAD_SIZE 2 // how many bytes to expect from each I2C salve node

define NODE_MAX 6 // maximum number of slave nodes (I2C addresses) to probe

define START_NODE 2 // The starting I2C address of slave nodes

define NODEREADDELAY 1000 // Some delay between I2C node reads

int nodePayload[PAYLOAD_SIZE];

void setup() { Serial.begin(9600);
Serial.println("MASTER READER NODE"); Serial.print("Maximum Slave Nodes: "); Serial.println(NODEMAX); Serial.print("Payload size: "); Serial.println(PAYLOADSIZE); Serial.println("***");

Wire.begin(); // Activate I2C link } ```

I2C-Master Sketch(2019-11-12)

` void loop() { for (int nodeAddress = START_NODE; nodeAddress <= NODE_MAX; nodeAddress++) { // we are starting from Node address 2 Wire.requestFrom(nodeAddress, PAYLOAD_SIZE); // request data from node# if(Wire.available() == PAYLOAD_SIZE) { // if data size is avaliable from nodes for (int i = 0; i < PAYLOAD_SIZE; i++) nodePayload[i] = Wire.read(); // get nodes data for (int j = 0; j < PAYLOAD_SIZE; j++) Serial.println(nodePayload[j]); // print nodes data<br /> Serial.println("*************************");<br /> } } delay(NODE_READ_DELAY); } `

I2C-Slave Sketch(2019-11-12)

```

include

define NODE_ADDRESS 2 // Change this unique address for each I2C slave node

define PAYLOAD_SIZE 2 // Number of bytes expected to be received by the master I2C node

byte nodePayload[PAYLOAD_SIZE];

void setup() {

Serial.begin(9600);
Serial.println("SLAVE SENDER NODE"); Serial.print("Node address: "); Serial.println(NODEADDRESS); Serial.print("Payload size: "); Serial.println(PAYLOADSIZE); Serial.println("***");

Wire.begin(NODE_ADDRESS); // Activate I2C network Wire.onRequest(requestEvent); // Request attention of master node } ```

I2C-Slave Sketch(2019-11-12)

``` void loop() { delay(100); nodePayload[0] = NODE_ADDRESS; // I am sending Node address back. Replace with any other data nodePayload[1] = analogRead(A0)/4; // Read A0 and fit into 1 byte. Replace this line with your sensor value

}

void requestEvent() { Wire.write(nodePayload,PAYLOAD_SIZE);
Serial.print("Sensor value: "); // for debugging purposes. Serial.println(nodePayload[1]); // for debugging purposes. } ```

I2C Circuit

1. Resistor 10K Ohm X 2: Pull-up resistors for the I2C SDA SCL lines
2. LED X 3: It's nice to have these LEDs to know when wire is applied to the microcontroller.
3. Resistor 300 Ohm to 1K Ohm X 3: Used in series with the LEDs.
4. Use the sensor out of the kit for demonstrating the Network