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Visitor
Visitor
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Registered: ‎10-21-2019

Zybo I2C Example Failed

Hello all,

I am using a Zybo 7000 developement board and am trying to create a project such that I can communicate with a sensor over I2C. 

I have programmed my fpga in Vivado, and added I2C scl and sda to pins W19 and W20 respectively. In sdk, I can complete the hello world and repeated start example with no issues. 

I read from another forum that using the "master polled" example was a good start for establishing communication as it was just simple read/write functions. 

Inside this master polled, I have changed the slave address from 0x55 to 0x62, as per my actual sensor address. Also I added additional 1k pull-up resistors in like with the SDA & SCL lines. I then run as debugger and the example fails. 

Am I missing a declaration somewhere? Thanks,

Russell

IMG_1313.PNG
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3 Replies
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Moderator
Moderator
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Registered: ‎04-09-2019

Can you please share your source code completely to understand what you are doing and slave device data sheet.

Regards,

Venu

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Visitor
Visitor
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Registered: ‎10-21-2019

DAC datasheet - https://www.sparkfun.com/datasheets/BreakoutBoards/MCP4725.pdf

Source Code is just master polled example with line that I changed to DAC hex address. 

/******************************************************************************
*
* Copyright (C) 2010 - 2019 Xilinx, Inc. All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* XILINX BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
* OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
* Except as contained in this notice, the name of the Xilinx shall not be used
* in advertising or otherwise to promote the sale, use or other dealings in
* this Software without prior written authorization from Xilinx.
*
******************************************************************************/
/*****************************************************************************/
/**
* @file xiicps_polled_master_example.c
*
* A design example of using the device in polled mode as master.
*
* The example uses buffer size 132. Please set the send buffer of the
* Aardvark device to be continuous 64 bytes from 0x00 to 0x3F.
*
* <pre> MODIFICATION HISTORY:
*
* Ver Who Date Changes
* ----- --- -------- -----------------------------------------------
* 1.00a jz 01/30/10 First release
*
* </pre>
*
****************************************************************************/

/***************************** Include Files **********************************/
#include "xparameters.h"
#include "xiicps.h"
#include "xil_printf.h"

/************************** Constant Definitions ******************************/

/*
* The following constants map to the XPAR parameters created in the
* xparameters.h file. They are defined here such that a user can easily
* change all the needed parameters in one place.
*/
#define IIC_DEVICE_ID XPAR_XIICPS_0_DEVICE_ID

/*
* The slave address to send to and receive from.
*/
#define IIC_SLAVE_ADDR 0x62 //This is the address of the Arduino ADC
#define IIC_SCLK_RATE 100000

/*
* The following constant controls the length of the buffers to be sent
* and received with the IIC.
*/
#define TEST_BUFFER_SIZE 132

/**************************** Type Definitions ********************************/


/************************** Function Prototypes *******************************/

int IicPsMasterPolledExample(u16 DeviceId);
/************************** Variable Definitions ******************************/

XIicPs Iic; /**< Instance of the IIC Device */

/*
* The following buffers are used in this example to send and receive data
* with the IIC.
*/
u8 SendBuffer[TEST_BUFFER_SIZE]; /**< Buffer for Transmitting Data */
u8 RecvBuffer[TEST_BUFFER_SIZE]; /**< Buffer for Receiving Data */


/******************************************************************************/
/**
*
* Main function to call the polled master example.
*
* @param None.
*
* @return XST_SUCCESS if successful, XST_FAILURE if unsuccessful.
*
* @note None.
*
*******************************************************************************/
int main(void)
{
int Status;

xil_printf("IIC Master Polled Example Test \r\n");

/*
* Run the Iic polled example in master mode, specify the Device
* ID that is specified in xparameters.h.
*/
Status = IicPsMasterPolledExample(IIC_DEVICE_ID);
if (Status != XST_SUCCESS) {
xil_printf("IIC Master Polled Example Test Failed \r\n");
return XST_FAILURE;
}

xil_printf("Successfully ran IIC Master Polled Example Test\r\n");
return XST_SUCCESS;
}

/*****************************************************************************/
/**
*
* This function sends data and expects to receive data from slave as modular
* of 64.
*
* This function uses interrupt-driven mode of the device.
*
* @param DeviceId is the Device ID of the IicPs Device and is the
* XPAR_<IICPS_instance>_DEVICE_ID value from xparameters.h
*
* @return XST_SUCCESS if successful, otherwise XST_FAILURE.
*
* @note None.
*
*******************************************************************************/
int IicPsMasterPolledExample(u16 DeviceId)
{
int Status;
XIicPs_Config *Config;
int Index;

/*
* Initialize the IIC driver so that it's ready to use
* Look up the configuration in the config table,
* then initialize it.
*/
Config = XIicPs_LookupConfig(DeviceId);
if (NULL == Config) {
return XST_FAILURE;
}

Status = XIicPs_CfgInitialize(&Iic, Config, Config->BaseAddress);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}

/*
* Perform a self-test to ensure that the hardware was built correctly.
*/
Status = XIicPs_SelfTest(&Iic);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}

/*
* Set the IIC serial clock rate.
*/
XIicPs_SetSClk(&Iic, IIC_SCLK_RATE);

/*
* Initialize the send buffer bytes with a pattern to send and the
* the receive buffer bytes to zero to allow the receive data to be
* verified.
*/
for (Index = 0; Index < TEST_BUFFER_SIZE; Index++) {
SendBuffer[Index] = (Index % TEST_BUFFER_SIZE);
RecvBuffer[Index] = 0;
}

/*
* Send the buffer using the IIC and ignore the number of bytes sent
* as the return value since we are using it in interrupt mode.
*/
Status = XIicPs_MasterSendPolled(&Iic, SendBuffer,
TEST_BUFFER_SIZE, IIC_SLAVE_ADDR);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}

/*
* Wait until bus is idle to start another transfer.
*/
while (XIicPs_BusIsBusy(&Iic)) {
/* NOP */
}

Status = XIicPs_MasterRecvPolled(&Iic, RecvBuffer,
TEST_BUFFER_SIZE, IIC_SLAVE_ADDR);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}

/*
* Verify received data is correct.
*/
for(Index = 0; Index < TEST_BUFFER_SIZE; Index ++) {

/* Aardvark as slave can only set 64 bytes for output */
if (RecvBuffer[Index] != Index % 64) {
return XST_FAILURE;
}
}

return XST_SUCCESS;
}

Thanks,

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Highlighted
Moderator
Moderator
536 Views
Registered: ‎04-09-2019

Please arrange your code w.r.to data sheet

1. The buffer size needs to be changed.

2.The following code not related to your sensor please remove

/*
* Verify received data is correct.
*/
for(Index = 0; Index < TEST_BUFFER_SIZE; Index ++) {

/* Aardvark as slave can only set 64 bytes for output */
if (RecvBuffer[Index] != Index % 64) {
return XST_FAILURE;
}
}

3. Write the actual values into the registers adn read it back and validate.

 

Regards,

Venu

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