forked from Elron_dev/elbear_arduino_bsp
92 lines
2.5 KiB
C++
92 lines
2.5 KiB
C++
// I2C slave
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#include <Wire.h>
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// The address on the I2C bus that we will assign to this device
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constexpr int MY_ADDRESS = 0x33;
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// Buffers for sending and receiving
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uint8_t slaveTxData[4] = {0x00, 0x10, 0x22, 0x84};
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uint8_t slaveRxData[8] = {0};
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// Function for receiving data from the I2C bus
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uint8_t slaveGetData(uint8_t *buf, uint8_t bufSize)
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{
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// If there are bytes available for reading, read them in a loop
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uint8_t n = 0;
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while (Wire.available())
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{
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// Read from the bus - from the master device
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buf[n] = Wire.read();
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// If the entire buffer is filled, stop reading
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if (++n == bufSize)
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break;
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}
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// Return the number of received bytes
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return n;
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}
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// Function for sending data via I2C bus
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uint8_t slaveSendData(uint8_t* data, uint8_t dataLen)
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{
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return Wire.write(data, dataLen);
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}
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// A function that will be called if the master requests data
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void requestEvent()
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{
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Serial.println("------------------------");
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Serial.println("Slave | Request event");
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// Send data
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uint8_t txBytesQty = slaveSendData(slaveTxData, sizeof(slaveTxData));
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// Show result
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if (txBytesQty == sizeof(slaveTxData))
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Serial.print("Slave | Bytes quantity sent: ");
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else
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Serial.print("Slave | Send ERROR! Bytes quantity sent: ");
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Serial.println(txBytesQty);
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slaveTxData[0] += 1; // Change the first byte for variety
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}
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// Function that will be called if the master sends data
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void receiveEvent(int bytesNum)
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{
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Serial.println("------------------------");
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Serial.println("Slave | Receive event");
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// Get new data
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uint8_t rxBytesQty = slaveGetData(slaveRxData, sizeof(slaveRxData));
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// Show result
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if (rxBytesQty == 0)
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Serial.println("Slave | Receive ERROR!");
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else
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{
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for (uint8_t i = 0; i < rxBytesQty; i++)
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{
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Serial.print("Slave | Received byte: 0x");
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Serial.println(slaveRxData[i], HEX);
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}
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}
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}
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// ----------------------------------------- //
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void setup()
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{
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Serial.begin(115200);
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while (!Serial);
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Serial.println("I2C slave start");
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// Start working with I2C as a slave device with the address MY_ADDRESS
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Wire.begin(MY_ADDRESS);
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// Register an event handler that will be called when data is requested by the master device
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Wire.onRequest(requestEvent);
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// Register an event handler that will be called after receiving data from the master device
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Wire.onReceive(receiveEvent);
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}
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void loop()
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{
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// Don't do anything in the loop, everything is implemented in the registered event handlers
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}
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