I2c连接XC8编译器v.1.38和MCC代码示例中出现两个错误

因此，对于我（作为asm用户和xc8初学者）来说，发现MCCI2c代码并不是一件容易的工作，因为它不太明显，比如：Start()、Write()、Stop()。而且我没有在网上找到示例。首先我检查了写函数，它没有工作。我发现固件在line:.(status==I2C_MESSAGE_PENDING);(它等待中断并在那里改变状态)进入无限循环。固件成功地进入其中，并选择正确的CASSESSMAStiORIDLE & gt；固件在它们之间循环。我检查了固件循环的LED。如果固件在某处- LED是打开的。然后我去示波器并没有找到任何CLK或数据信号。隐马尔可夫模型。。。所以我返回了II2CIILIALIALIZE（）；我使用了主模式，400 KHz的速度和7位的地址。2个上拉电阻2KOHM到VDD 5V。MCU -PIC16F1454与PoCc0和PoTC1引脚= CLK和数据。48兆赫FRQ（16X3PLL）。使用I2C，我使用正确的UB-UART CDC连接。我需要帮助找到错误的地方。编辑：我发现了2个错误。1）错误理解MCC波特率发生器的频率值。见下面的帖子。2)我的错误-我没有在PORTC上把模拟转换为数字输入，因为我认为PIC16F1454没有ADC，所以引脚总是数字的。



      以下为原文

    So, for me (as asm user and xc8 beginner) discovering MCC i2c code wasn’t an easy job because it wasn’t too obvious like:
Start();
Write();
Stop().
And I didn’t find examples on the internet.

Since a week I made functions for writing and reading ext EEPROM 24AA256. First I checked the Write function and it didnt work. I found the firmware goes to infinite loop at line: while(status == I2C_MESSAGE_PENDING); (which waiting for interrupts and change the status there).

After that I checked the function calling by i2c interrupts: I2C_ISR();. Firmware successfully enter in it and choose the right cases S_MASTER_IDLE -> S_MASTER_SEND_ADDR -> S_MASTER_SEND_DATA. And the firmware loops here between them. I checked where the firmware loops by LED. If firmware was somewhere - LED is on.

Then I took oscilloscope and didnt find any CLK or DATA signal. Hmm... So I returned to I2C_Initialize();.

I use Master mode, 400kHz speed with 7bit address. 2 pull-up resistors 2kOhm to Vdd 5V. MCU - PIC16F1454 with PORTC0 and PORTC1 pins = CLK and DATA. 48MHz freq (16x3PLL). And with I2C I use correctly working USB-UART CDC connection.

I need help to find where I mistake.

EDIT: I found 2 mistakes. 1) Bug or incomprehension MCC baudrate generator value of frequency. See the post below. 2) My mistake - I didnt switch analog to digital inputs on PORTC because of my thoughts that PIC16F1454 hasn't ADC's so pins are always digital.
Now write and read to EEPROM works fine, so that's my read and write functions:

#ifndef _APP_I2C_H
#define _APP_I2C_H

#define RETRY_MAX 100 // define the retry count
#define EE24AA256_ADDRESS 0x50 // slave device address
I2C_MESSAGE_STATUS status;

uint8_t sourceData[16] = { 0xA0, 0xA1, 0xA2, 0xA3,
                               0xA4, 0xA5, 0xA6, 0xA7,
                               0xA8, 0xA9, 0xAA, 0xAB,
                               0xAC, 0xAD, 0xAE, 0xAF };
uint8_t savedDEVData[16];

//Declarations
void I2C_write_byte(
        uint8_t DEV_address, // slave device address
        uint16_t DEV_data_address, // starting EEPROM address
        uint8_t *pData, //first byte of data to write
        uint16_t nCount); //number of bytes to write
//Call example:
//I2C_write_byte(EE24AA256_ADDRESS, 0x0010, sourceData, 16);

void I2C_read_byte(
        uint8_t DEV_address, // slave device address
        uint16_t DEV_data_address,
        uint8_t *pData,
        uint16_t nCount);
//Call example:
//I2C_read_byte(EE24AA256_ADDRESS, 0x0010, savedDEVData, 16);







#endif //_I2C_H


#include
#include
#include "i2c/i2c.h"
#include "app_i2c.h"
#include "system.h"


/*=============================================================================
*
* Write to I2C
*
*===========================================================================*/
void I2C_write_byte(
        uint8_t DEV_address, // slave device address
        uint16_t DEV_data_address, // starting data address
        uint8_t *pData, //first address of source data
        uint16_t nCount) //number of bytes to write
{
    uint8_t writeBuffer[3]; //2 bytes of DEV_data_address + 1 byte data
    uint16_t timeOut;
    uint16_t counter;
    uint8_t *pD;
    pD = pData;
    status = I2C_MESSAGE_PENDING;

    for (counter = 0; counter < nCount; counter++)
    {
            writeBuffer[0] = (DEV_data_address >> 8); // high address
            writeBuffer[1] = (uint8_t)(DEV_data_address); // low low address
            writeBuffer[2] = *pD++; // data to be written
            
            timeOut = 0;
            
            while(status != I2C_MESSAGE_FAIL)
            {
                // write one byte to DEV (3 is the number of bytes to write)
                I2C_MasterWrite(writeBuffer, 3, DEV_adress, &status);
               
                // wait for the message to be sent or status has changed.
                // in I2C_MasterWrite - MasterTRBInsert we can find:
                // PIR1bits.SSP1IF = true; which trigger the first interrupt
                while(status == I2C_MESSAGE_PENDING);

                if (status == I2C_MESSAGE_COMPLETE)
                    break;
                // check for max retry and skip this byte
                if (timeOut == RETRY_MAX)
                {
                    status == I2C_MESSAGE_FAIL;
                    break;
                }
                else
                    timeOut++;
            }
            if (status == I2C_MESSAGE_FAIL)
                break;
            else
                DEV_data_address++;
    }//end "for" number of bytes to write
   
    return;
}//end of DEV_write
            
            
            

/*=============================================================================
*
* Read from I2C Device
*
*===========================================================================*/
void I2C_read_byte(
        uint8_t DEV_address, // slave device address
        uint16_t DEV_data_address, // starting data address
        uint8_t *pData, //first address of saved data from DEV
        uint16_t nCount) //number of bytes to write
{
    I2C_MESSAGE_STATUS status;
    uint8_t writeBuffer[3];
    uint16_t timeOut;
    uint16_t counter;
    uint8_t *pD, ret;
    pD = pData;
    status = I2C_MESSAGE_PENDING;
               
    //WRITE data address to DEV which we wanna read
    for (counter = 0; counter < nCount; counter++)
    {
        // build the write buffer first
        writeBuffer[0] = (DEV_data_address >> 8); // high address
        writeBuffer[1] = (uint8_t)(DEV_data_address); // low low address

        timeOut = 0;
            
        while(status != I2C_MESSAGE_FAIL)
        {
            // write one byte to DEV (2 is the count of bytes to write)
            I2C_MasterWrite(writeBuffer, 2, DEV_address, &status);
            // wait for the message to be sent or status has changed.
            while(status == I2C_MESSAGE_PENDING);

            if (status == I2C_MESSAGE_COMPLETE)
                        break;
            // check for max retry and skip this byte
            if (timeOut == RETRY_MAX)
            {
                status == I2C_MESSAGE_FAIL;
                break;
            }
            else
                timeOut++;
        }

            if (status == I2C_MESSAGE_COMPLETE)
            {
            // this portion will read the byte from the memory location.
                timeOut = 0;
                while(status != I2C_MESSAGE_FAIL)
                {
                    // write one byte to DEV(2 is the count of bytes to write)
                    I2C_MasterRead(pD, 1, DEV_address, &status);
                    // wait for the message to be sent or status has changed.
                    while(status == I2C_MESSAGE_PENDING);

                    if (status == I2C_MESSAGE_COMPLETE)
                        break;
                        // check for max retry and skip this byte
                    if (timeOut == RETRY_MAX)
                    {
                        status == I2C_MESSAGE_FAIL;
                        break;
                    }
                    else
                        timeOut++;
                }
            }
                    // exit if the last transaction failed
            if (status == I2C_MESSAGE_FAIL)
                break;
            pD++;
            DEV_data_address++;
    }
    return;
}

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