LPC824 i2c reading problem

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LPC824 i2c reading problem

763 Views
aravindpb5009
Contributor III

Hai 

         i am using the lpc824  mcuxpresso I need to read the adc in (ADS1115 )  I2C module . when i try to read that it doesn't give any value from the ads1115 , for checking purpose i tried arduino uno in arduino the o/p has got correctly in lpc824 it doesn't  READ the adc value  plz let me know the solution in below i provide my code plz share me the solution i am asking this 3 weeks but till i didn't get any answer

/*
* Copyright (c) 2016, Freescale Semiconductor, Inc.
* Copyright 2016-2019 NXP
* All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/

/* Standard C Included Files */
#include <stdio.h>
#include <string.h>
#include "board.h"
#include "fsl_debug_console.h"
#include "fsl_i2c.h"
#include "fsl_i2c.h"
#include <stdlib.h>
#include <string.h>
#include "pin_mux.h"
#include "fsl_device_registers.h"
#include "fsl_common.h"
#include"lpc8xx_i2c.h"
/*******************************************************************************
* Definitions
******************************************************************************/
#define START_BYTE "startbyte\n\r"
#define SEPERATE_BYTE "-"
#define STOP_BYTE "stopbyte\n\r"

uint8_t F_DEMOCHECK[] = "4096";
uint8_t s_identifier[] = "SPEEDTECH";
uint8_t g_demoInfo[] = " IOT CHECKING............\r\n";
uint8_t A_sensor1[] = " ADC_1 SENSOR_READING:\r\n";
uint8_t A_sensor2[] = " ADC_2 SENSOR_READING:\r\n";
uint8_t A_sensor3[] = " ADC_3 SENSOR_READING:\r\n";
uint8_t A_sensor4[] = " ADC_4 SENSOR_READING:\r\n";
uint8_t g_logInfo[] = "The received characters are:";
uint8_t g_overFlowInfo[] = "\r\nYou have input too many characters, Please try again!\r\n";
uint8_t g_checking[] = "\r\n condition stopped before the while loop ...!\r\n";

#define EXAMPLE_USART USART0
#define EXAMPLE_USART_CLK_SRC kCLOCK_MainClk
#define EXAMPLE_USART_CLK_FREQ CLOCK_GetFreq(EXAMPLE_USART_CLK_SRC)
#define EXAMPLE_USART_IRQn USART0_IRQn

#define EXAMPLE_I2C_MASTER_BASE (I2C0_BASE)
#define I2C_MASTER_CLOCK_FREQUENCY (30000000)
#define WAIT_TIME 10U
#define EXAMPLE_I2C_MASTER ((I2C_Type *)EXAMPLE_I2C_MASTER_BASE)

#define Self_Slave_address 0x49U
#define ADS1015_REG_POINTER_MASK (0x03)
#define ADS1015_REG_POINTER_CONVERT (0x00)
#define ADS1015_REG_POINTER_CONFIG (0x01)
#define ADS1015_REG_POINTER_LOWTHRESH (0x02)
#define ADS1015_REG_POINTER_HITHRESH (0x03)
#define config_high 0x84
#define config_low 0x83
#define config_line 0x0083


int main(void)
{
unsigned int msb_byte,lsb_byte,msb=5,lsb=9;
unsigned char * tx_ptr;
unsigned int temp1=5009;

// i2c_master_config_t masterConfig;


/* Enable clock of uart0. */
CLOCK_EnableClock(kCLOCK_Uart0);
/* Ser DIV of uart0. */
CLOCK_SetClkDivider(kCLOCK_DivUsartClk, 1U);
/* Enable clock of i2c0. */
CLOCK_EnableClock(kCLOCK_I2c0);

BOARD_InitPins();
BOARD_BootClockIRC12M();
BOARD_InitDebugConsole();
// LPC_SYSCON->PRESETCTRL &= (I2C0_RST_N);
// LPC_SYSCON->PRESETCTRL |= ~(I2C0_RST_N);


// Configure the I2C0 clock divider
// Desired bit rate = Fscl = 100,000 Hz (1/Fscl = 10 us, 5 us low and 5 us high)
// Use default clock high and clock low times (= 2 clocks each)
// So 4 I2C_PCLKs = 100,000/second, or 1 I2C_PCLK = 400,000/second
// I2C_PCLK = SystemClock = 30,000,000/second, so we divide by 30/.4 = 75
// Remember, value written to DIV divides by value+1

I2C0->CLKDIV = (75-1);
I2C0->CFG = CFG_MSTENA| CFG_SLVENA ;

I2C0->INTENSET = STAT_MSTPEND|STAT_SLVPEND ;

I2C0->MSTCTL = CTL_MSTSTART; // Start the transaction by setting the MSTSTART bit to 1 in the Master control register.
I2C0->MSTDAT = (Self_Slave_address<<1) | 0; // Address with 0 for RWn bit (WRITE)
WaitI2CMasterState(I2C_STAT_MSTST_TX ); // Wait for the address to be ACK'd
I2C0->MSTDAT = ADS1015_REG_POINTER_CONFIG; // Address with 0 for RWn bit (WRITE)
WaitI2CMasterState( I2C_STAT_MSTST_TX ); // Wait for the address to be ACK'd
I2C0->MSTDAT = config_high; // Address with 0 for RWn bit (WRITE) config
WaitI2CMasterState( I2C_STAT_MSTST_TX ); // Wait for the address to be ACK'd
I2C0->MSTDAT =config_low; // Address with 0 for RWn bit (WRITE) config
WaitI2CMasterState( I2C_STAT_MSTST_TX ); // Wait for the address to be ACK'd
I2C0->MSTCTL = CTL_MSTSTOP; // Send a stop to end the transaction
// I2C0->MSTDAT = ADS1015_REG_POINTER_CONVERT;
// WaitI2CMasterState(I2C0, I2C_STAT_MSTST_TX); // Wait for the address to be ACK'd
// I2C0->MSTCTL = CTL_MSTCONTINUE;


// I2C0->MSTCTL = CTL_MSTSTART;
// I2C0->MSTDAT = (Self_Slave_address<<1) | 0; // Address with 0 for RWn bit (write)
// WaitI2CMasterState( I2C_STAT_MSTST_TX);
// I2C0->MSTDAT = ADS1015_REG_POINTER_CONVERT;
// WaitI2CMasterState( I2C_STAT_MSTST_TX); // Wait for the address to be ACK'd
// I2C0->MSTCTL = CTL_MSTSTOP;

while(1)
{
////////////////// write to ads1115 conversion register/////////////////////////////////////////////

USART_WriteBlocking(EXAMPLE_USART, START_BYTE , (sizeof( START_BYTE ))-1); // SEPERATE BYTE '-

// I2C0->MSTCTL = CTL_MSTSTART;
// I2C0->MSTDAT = (Self_Slave_address<<1) | 0; // Address with 0 for RWn bit (write)
// WaitI2CMasterState(I2C0, I2C_STAT_MSTST_TX); // Wait for the address to be ACK'd
// //PutTerminalString(LPC_USART0, start_bit);
// I2C0->MSTDAT = ADS1015_REG_POINTER_CONVERT;
// WaitI2CMasterState(I2C0, I2C_STAT_MSTST_TX); // Wait for the address to be ACK'd
// PutTerminalString(LPC_USART0, start_bit);
// I2C0->MSTCTL = CTL_MSTSTOP; // Send a stop to end the transaction
// // I2C0->MSTCTL = CTL_MSTSTART; // Start the transaction by setting the MSTSTART bit to 1 in the Master control register.


I2C0->MSTCTL = CTL_MSTSTART;
I2C0->MSTDAT = (Self_Slave_address<<1) | 1; // Address with 0 for RWn bit (read)
WaitI2CMasterState( I2C_STAT_MSTST_RX);
msb_byte = I2C0->MSTDAT; // Read the data
WaitI2CMasterState( I2C_STAT_MSTST_RX);
//USART_WriteBlocking1(EXAMPLE_USART, msb_byte); // SEPERATE BYTE '-
lsb_byte = I2C0->MSTDAT; // Read the data
WaitI2CMasterState( I2C_STAT_MSTST_RX);
USART_WriteBlocking1(EXAMPLE_USART, msb_byte, lsb_byte ); // SEPERATE BYTE '-
USART_WriteBlocking(EXAMPLE_USART, STOP_BYTE , (sizeof( STOP_BYTE ))-1); // SEPERATE BYTE '-
// slave_rx_data[slave_data_counter++] = temp; // Store it in the array, increment counter
// PutTerminalString1(LPC_USART0, temp1);
//PutTerminalString1(LPC_USART0, msb_byte);
// PutTerminalString1(LPC_USART0, lsb_byte);
// PutTerminalchar0(LPC_USART0, lsb_byte);
// I2C0->MSTCTL = CTL_MSTCONTINUE; // ACK the data
// PutTerminalString(LPC_USART0,temp);
// WaitI2CMasterState(I2C0, I2C_STAT_MSTST_RX); // Wait for the data to be ACK'd
// NVIC_EnableIRQ(I2C0_IRQn);
I2C0->MSTCTL = CTL_MSTSTOP; // Send a stop to end the transaction
//PutTerminalString(LPC_USART0, (uint8_t *)stop_bit);// Print a massage
} // end of while 1

} // end of main

/////////////////////////////////////

1 Reply

470 Views
soledad
NXP Employee
NXP Employee

Hi, 

Unfortunately, I don't have the exact code because I don't have the external ADC. I suggest taking as base the I2C master polling_b2b_transfer.

The i2c_polling_b2b_transfer_master example shows how to use i2c driver as master to do board to board transfer
using polling method:

In this example, one i2c instance as master and another i2c instance on the other board as slave. Master sends a
piece of data to slave, and receive a piece of data from slave. This example checks if the data received from
slave is correct.

You need to consider the following: 

1. Connect to P0_11 (I2C0_SDA) and P0_10 (I2C0_SCL) the external ADC device.

2. Check the pull-up resistances.

3. Check the correct address from the external ADC  

/*
* Copyright (c) 2016, Freescale Semiconductor, Inc.
* Copyright 2016-2019 NXP
* All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/

/* Standard C Included Files */
#include <stdio.h>
#include <string.h>
#include "board.h"
#include "fsl_debug_console.h"
#include "fsl_i2c.h"

#include "pin_mux.h"
/*******************************************************************************
* Definitions
******************************************************************************/
#define EXAMPLE_I2C_MASTER_BASE (I2C0_BASE)
#define I2C_MASTER_CLOCK_FREQUENCY (12000000)
#define WAIT_TIME 10U
#define EXAMPLE_I2C_MASTER ((I2C_Type *)EXAMPLE_I2C_MASTER_BASE)

#define I2C_MASTER_SLAVE_ADDR_7BIT 0x7EU             
#define I2C_BAUDRATE 100000U
#define I2C_DATA_LENGTH 33U
/*******************************************************************************
* Prototypes
******************************************************************************/

/*******************************************************************************
* Variables
******************************************************************************/
uint8_t g_master_txBuff[I2C_DATA_LENGTH];
uint8_t g_master_rxBuff[I2C_DATA_LENGTH];

/*******************************************************************************
* Code

******************************************************************************/

/*!
* @brief Main function
*/
int main(void)
{
i2c_master_config_t masterConfig;
status_t reVal = kStatus_Fail;
uint8_t deviceAddress = 0x01U;       // Please check the correct address of the external ADC

/* Enable clock of uart0. */
CLOCK_EnableClock(kCLOCK_Uart0);
/* Ser DIV of uart0. */
CLOCK_SetClkDivider(kCLOCK_DivUsartClk, 1U);
/* Enable clock of i2c0. */
CLOCK_EnableClock(kCLOCK_I2c0);

BOARD_InitPins();
BOARD_BootClockIRC12M();
BOARD_InitDebugConsole();

PRINTF("\r\nI2C board2board polling example -- Master transfer.\r\n");

/* Set up i2c master to send data to slave*/
/* First data in txBuff is data length of the transmiting data. */
g_master_txBuff[0] = I2C_DATA_LENGTH - 1U;
for (uint32_t i = 1U; i < I2C_DATA_LENGTH; i++)
{
g_master_txBuff[i] = i - 1;
}

PRINTF("Master will send data :");
for (uint32_t i = 0U; i < I2C_DATA_LENGTH - 1U; i++)
{
if (i % 8 == 0)
{
PRINTF("\r\n");
}
PRINTF("0x%2x ", g_master_txBuff[i + 1]);
}
PRINTF("\r\n\r\n");

/*
* masterConfig.debugEnable = false;
* masterConfig.ignoreAck = false;
* masterConfig.pinConfig = kI2C_2PinOpenDrain;
* masterConfig.baudRate_Bps = 100000U;
* masterConfig.busIdleTimeout_ns = 0;
* masterConfig.pinLowTimeout_ns = 0;
* masterConfig.sdaGlitchFilterWidth_ns = 0;
* masterConfig.sclGlitchFilterWidth_ns = 0;
*/
I2C_MasterGetDefaultConfig(&masterConfig);

/* Change the default baudrate configuration */
masterConfig.baudRate_Bps = I2C_BAUDRATE;

/* Initialize the I2C master peripheral */
I2C_MasterInit(EXAMPLE_I2C_MASTER, &masterConfig, I2C_MASTER_CLOCK_FREQUENCY);

/* Send master blocking data to slave */
if (kStatus_Success == I2C_MasterStart(EXAMPLE_I2C_MASTER, I2C_MASTER_SLAVE_ADDR_7BIT, kI2C_Write))
{
/* subAddress = 0x01, data = g_master_txBuff - write to slave.
start + slaveaddress(w) + subAddress + length of data buffer + data buffer + stop*/
reVal = I2C_MasterWriteBlocking(EXAMPLE_I2C_MASTER, &deviceAddress, 1, kI2C_TransferNoStopFlag);
if (reVal != kStatus_Success)
{
return -1;
}

reVal = I2C_MasterWriteBlocking(EXAMPLE_I2C_MASTER, g_master_txBuff, I2C_DATA_LENGTH, kI2C_TransferDefaultFlag);
if (reVal != kStatus_Success)
{
return -1;
}

reVal = I2C_MasterStop(EXAMPLE_I2C_MASTER);
if (reVal != kStatus_Success)
{
return -1;
}
}

/* Wait until the slave is ready for transmit, wait time depend on user's case.
Slave devices that need some time to process received byte or are not ready yet to
send the next byte, can pull the clock low to signal to the master that it should wait.*/
for (uint32_t i = 0U; i < WAIT_TIME; i++)
{
__NOP();
}

PRINTF("Receive sent data from slave :");

/* Receive blocking data from slave */
/* subAddress = 0x01, data = g_master_rxBuff - read from slave.
start + slaveaddress(w) + subAddress + repeated start + slaveaddress(r) + rx data buffer + stop */
if (kStatus_Success == I2C_MasterStart(EXAMPLE_I2C_MASTER, I2C_MASTER_SLAVE_ADDR_7BIT, kI2C_Write))
{
reVal = I2C_MasterWriteBlocking(EXAMPLE_I2C_MASTER, &deviceAddress, 1, kI2C_TransferNoStopFlag);
if (reVal != kStatus_Success)
{
return -1;
}

reVal = I2C_MasterRepeatedStart(EXAMPLE_I2C_MASTER, I2C_MASTER_SLAVE_ADDR_7BIT, kI2C_Read);
if (reVal != kStatus_Success)
{
return -1;
}

reVal =
I2C_MasterReadBlocking(EXAMPLE_I2C_MASTER, g_master_rxBuff, I2C_DATA_LENGTH - 1, kI2C_TransferDefaultFlag);
if (reVal != kStatus_Success)
{
return -1;
}

reVal = I2C_MasterStop(EXAMPLE_I2C_MASTER);
if (reVal != kStatus_Success)
{
return -1;
}
}

for (uint32_t i = 0U; i < I2C_DATA_LENGTH - 1; i++)
{
if (i % 8 == 0)
{
PRINTF("\r\n");
}
PRINTF("0x%2x ", g_master_rxBuff[i]);
}
PRINTF("\r\n\r\n");

/* Transfer completed. Check the data.*/
for (uint32_t i = 0U; i < I2C_DATA_LENGTH - 1; i++)
{
if (g_master_rxBuff[i] != g_master_txBuff[i + 1])
{
PRINTF("\r\nError occurred in the transfer ! \r\n");
break;
}
}

PRINTF("\r\nEnd of I2C example .\r\n");
while (1)
{
}
}

Regards 

Soledad