I2C_Interface.c

/*
* This file includes all the required source code to interface
* the I2C peripheral.
*/

#ifndef DEVICE_CONNECTED
    #define DEVICE_CONNECTED 1
#endif

#ifndef DEVICE_UNCONNECTED
    #define DEVICE_UNCONNECTED 0
#endif

#include "I2C_Interface.h" 
#include "I2C_Master.h"

    I2C_ErrorCode I2C_Peripheral_Start(void) 
    {
        // Start I2C peripheral
        I2C_Master_Start();  
        
        // Return no error since start function does not return any error
        return I2C_NO_ERROR;
    }
    
    
    I2C_ErrorCode I2C_Peripheral_Stop(void)
    {
        // Stop I2C peripheral
        I2C_Master_Stop();
        // Return no error since stop function does not return any error
        return I2C_NO_ERROR;
    }

    I2C_ErrorCode I2C_Peripheral_ReadRegister(uint8_t device_address, 
                                            uint8_t register_address,
                                            uint8_t* data)
    {
        // Send start condition
        uint8_t error = I2C_Master_MasterSendStart(device_address,I2C_Master_WRITE_XFER_MODE);
        if (error == I2C_Master_MSTR_NO_ERROR)
        {
            // Write address of register to be read
            error = I2C_Master_MasterWriteByte(register_address);
            if (error == I2C_Master_MSTR_NO_ERROR)
            {
                // Send restart condition
                error = I2C_Master_MasterSendRestart(device_address, I2C_Master_READ_XFER_MODE);
                if (error == I2C_Master_MSTR_NO_ERROR)
                {
                    // Read data without acknowledgement
                    *data = I2C_Master_MasterReadByte(I2C_Master_ACK_DATA);
                    // Send stop condition and return no error
                    I2C_Master_MasterSendStop();
                    return I2C_NO_ERROR;
                }
            }
        }
        // Send stop condition if something went wrong
        I2C_Master_MasterSendStop();
        // Return error code
        return I2C_ERROR;
    }
    
    I2C_ErrorCode I2C_Peripheral_ReadRegisterMulti(uint8_t device_address,
                                                uint8_t register_address,
                                                uint8_t register_count,
                                                uint8_t* data)
    {
        // Send start condition
        uint8_t error = I2C_Master_MasterSendStart(device_address,I2C_Master_WRITE_XFER_MODE);
        if (error == I2C_Master_MSTR_NO_ERROR)
        {
            // Write address of register to be read with the MSB equal to 1
            // register_address |= 0x80;
            error = I2C_Master_MasterWriteByte(register_address);
            if (error == I2C_Master_MSTR_NO_ERROR)
            {
                // Send restart condition
                error = I2C_Master_MasterSendRestart(device_address, I2C_Master_READ_XFER_MODE);
                if (error == I2C_Master_MSTR_NO_ERROR)
                {
                    // Continue reading until we have register to read
                    uint8_t counter = register_count;
                    while(counter>1)
                    {
                        data[register_count-counter] =
                            I2C_Master_MasterReadByte(I2C_Master_ACK_DATA);
                        counter--;
                    }
                    // Read last data without acknowledgement
                    data[register_count-1]
                        = I2C_Master_MasterReadByte(I2C_Master_NAK_DATA);
                    // Send stop condition and return no error
                    I2C_Master_MasterSendStop();
                    return I2C_NO_ERROR;
                }
            }
        }
        // Send stop condition if something went wrong
        I2C_Master_MasterSendStop();
        // Return error code
        return I2C_ERROR;
    }
    
    I2C_ErrorCode I2C_Peripheral_WriteRegister(uint8_t device_address,
                                            uint8_t register_address,
                                            uint8_t data)
    {
        // Send start condition
        uint8_t error = I2C_Master_MasterSendStart(device_address, I2C_Master_WRITE_XFER_MODE);
        if (error == I2C_Master_MSTR_NO_ERROR)
        {
            // Write register address
            error = I2C_Master_MasterWriteByte(register_address);
            if (error == I2C_Master_MSTR_NO_ERROR)
            {
                // Write byte of interest
                error = I2C_Master_MasterWriteByte(data);
                if (error == I2C_Master_MSTR_NO_ERROR)
                {
                    // Send stop condition
                    I2C_Master_MasterSendStop();
                    // Return with no error
                    return I2C_NO_ERROR;
                }
            }
        }
        // Send stop condition in case something didn't work out correctly
        I2C_Master_MasterSendStop();
        // Return error code
        return I2C_ERROR;
    }
    
    I2C_ErrorCode I2C_Peripheral_WriteRegisterNoData(uint8_t device_address,
                                            uint8_t register_address)
    {
        // Send start condition
        uint8_t error = I2C_Master_MasterSendStart(device_address, I2C_Master_WRITE_XFER_MODE);
        if (error == I2C_Master_MSTR_NO_ERROR)
        {
            // Write register address
            error = I2C_Master_MasterWriteByte(register_address);
            if (error == I2C_Master_MSTR_NO_ERROR)
            {
                // Send stop condition
                I2C_Master_MasterSendStop();
                // Return with no error
                return I2C_NO_ERROR;
                
            }
        }
        // Send stop condition in case something didn't work out correctly
        I2C_Master_MasterSendStop();
        // Return error code
        return I2C_ERROR;
    }
    
    I2C_ErrorCode I2C_Peripheral_WriteRegisterMulti(uint8_t device_address,
                                            uint8_t register_address,
                                            uint8_t register_count,
                                            uint8_t* data)
    {
        // Send start condition
        uint8_t error = I2C_Master_MasterSendStart(device_address, I2C_Master_WRITE_XFER_MODE);
        if (error == I2C_Master_MSTR_NO_ERROR)
        {
            // Write register address
            error = I2C_Master_MasterWriteByte(register_address);
            if (error == I2C_Master_MSTR_NO_ERROR)
            {
                // Continue writing until we have data to write
                uint8_t counter = register_count;
                while(counter > 0)
                {
                    error = I2C_Master_MasterWriteByte(data[register_count-counter]);
                    if (error != I2C_Master_MSTR_NO_ERROR)
                    {
                        // Send stop condition
                        I2C_Master_MasterSendStop();
                        // Return error code
                        return I2C_ERROR;
                    }
                    counter--;
                }
                // Send stop condition and return no error
                I2C_Master_MasterSendStop();
                return I2C_NO_ERROR;
            }
        }
        // Send stop condition in case something didn't work out correctly
        I2C_Master_MasterSendStop();
        // Return error code
        return I2C_ERROR;
    }
    
    
    I2C_ErrorCode I2C_Peripheral_IsDeviceConnected(uint8_t device_address, I2C_Connection* connection)
    {
        // Send a start condition followed by a stop condition
        uint8_t error = I2C_Master_MasterSendStart(device_address, I2C_Master_WRITE_XFER_MODE);
        I2C_Master_MasterSendStop();
        // If no error generated during stop, device is connected
        if (error == I2C_Master_MSTR_NO_ERROR)
        {
            *connection = I2C_DEV_CONNECTED;
            return I2C_NO_ERROR;
        }
        else
        {
            *connection = I2C_DEV_UNCONNECTED;
            return I2C_ERROR;
        }
        
    }

/* [] END OF FILE */