charge_controller_target_mspm0L1304/src/i2c_comm/mcu_slave_interface.c

/*
References: https://stackoverflow.com/questions/246127/why-is-volatile-needed-in-c

*/

#include "src/battery_data/battery.h"
#include "mcu_slave_interface.h"
#include "ti/driverlib/dl_i2c.h"
#include <stdio.h>
#include <string.h>
/*Function to Rx and Tx data from Target to Controller*/
// The code has multiple i2c instances (multiple MCUs connected) from which we
// need to select the right one, passing a pointer as an argument

void mcu_i2c_handle(I2C_Regs *i2c) {
  printf("MCU interrupt triggered\n");
  uint8_t receivedCommand = DL_I2C_receiveTargetData(i2c);
  printf("[SLAVE] Received Command: 0x%02X\n", receivedCommand);
  uint8_t tx_buffer[8] = {0};
  //changed to volatile variable, so that the compiler cannot optimize the variable out and is forced to do as told by the code
  volatile uint8_t rx_buffer[8] = {0};
  /*Handling GET commands with bitmasking*/
  // GET command for ADC(Battery Measurement): Voltage, Current, Temperature
  if ((receivedCommand & 0xF0) == 0x60) {
    uint8_t slot = receivedCommand & 0x0F;
    if (slot > NUM_SLOTS) {
      DL_I2C_flushTargetTXFIFO(i2c);
      return;
    }
    // Struct for voltage, current and temperature
    BatteryMeasurementData battery_measure;
    // take the updated battery measurement from the battery struct and store it
    // in the battery_measure struct
    battery_measure.voltage = batteries[slot].voltage;
    battery_measure.current = batteries[slot].current;
    battery_measure.temperature = batteries[slot].temperature;
    // Copying the memory block from battery_measure struct to tx_buffer:
    memcpy(tx_buffer, &battery_measure, sizeof(BatteryMeasurementData));
    DL_I2C_fillTargetTXFIFO(i2c, tx_buffer, sizeof(BatteryMeasurementData));
    printf("Battery Measurement Sent to MCU. \n");
    DL_I2C_flushTargetTXFIFO(i2c);
  }
  
}