Use ADXL345 and KL25Z

[michelmeunier]

Hello,

I try to make a connection between ADXL345 accelerometer and KL25Z via SPI.

I have connected the ADXL345 like that:

PTD0 SPI0_PCS0 to CS

PTD2 SPI0_MOSI to SDA

PTD3 SPI0_MISO to SDO

PTD1 SPI0_SCK  to SCL

Next I have used the SPIMaster_LDD component

	LDD_TDeviceData *masterDevData;
	uint8_t Adresse,Value,Error;

  PE_low_level_init();

  masterDevData=SM1_Init(NULL);

  Adresse=0x00+0x80;

  Error=SM1_SendBlock(masterDevData,&Adresse,1);  //to get value at adress 0x00

  Error=SM1_ReceiveBlock(masterDevData,&Value,1); //I should received 0x5A but I received 0x00

Any idea?

Thanks

[michelmeunier]

Hello,

After a lot of failure, I have decided to write my own SPI-read function.

The source is quite simple and it works!! but only one time :-( I think there is a problem with SPMF but I don't understand very well in the documentation:

------------------

SPMF is set after SPRF is 1 when the value in the receive data buffer matches the value in the M register.

To clear the flag, read SPMF when it is set and then write a 1 to it.

0 Value in the receive data buffer does not match the value in the M register

1 Value in the receive data buffer matches the value in the M register

--------------------

In fact the first time I read the adress 0x00 of the ADXL345, I get 0xe5 wich is ok, but after if I try to read an other adresses, I allways get 0xe5!!In fact it's impossible to write a new value in SPI0_D.

my code is:

------------------------------

uint8_t spi_read(uint8_t adresse)

{

    uint8_t retour=0,dummy;

  while(!(SPI_S_SPTEF_MASK & SPI0_S))

  {    }  //While buffer is not empty do nothing

  SPI0_D =adresse+0x80;    //write adress+0x80 (read mode)

  while(!(SPI_S_SPRF_MASK & SPI0_S))

  {    } //While received buffer is not full do nothing 

  retour=SPI0_D;   //read the received value

dummy=(SPI_S_SPMF_MASK & SPI0_S);

SPI0_S |= SPI_S_SPMF_MASK;

  return retour;

}

---------------------------------------------

Thanks

Michel

[Alice_Yang]

Hello Michel,

- The S register must be read when SPTEF is set before writing to the SPI data register; otherwise, the

write is ignored.

- About the SPMF register , i think it is have no link with your problem .

Hope it helps

Have a great day,
Alice Yang

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[michelmeunier]

- The S register must be read when SPTEF is set before writing to the SPI data register; otherwise, the

write is ignored.

Hello Alice,

I don't see what you mean, because when I do:

while(!(SPI_S_SPTEF_MASK & SPI0_S))

  {    }  //While buffer is not empty do nothing

I read S register, no?

for

- About the SPMF register , i think it is have no link with your problem .

you are right, it's about the compare register, and have nothing to do with my problem.

Michel

[Alice_Yang]

Hello Michel,

After you read the 0X00  address of ADXL345 , then  initialize the ADXL345 ,

especially configure the POWER_CTL(0x2D) register the D3 bit to Measure(1) mode ,

then  read the other register .

BR

Alice

[Alice_Yang]

Hello Michel,

What function do you want to realize about this :

Adresse=0x00+0x80;
  Error=SM1_SendBlock(masterDevData,&Adresse,1);  //to get value at adress 0x00

Do you want to read the DEVID ?  While the DEVID value is 0xE5 , so could you please tell me what do you want

to do , thank !

BR

Alice

[michelmeunier]

Hello,

Of course my final goal is to read DEVID of the ADXL345, but to read the coordinate of 1g vector.

But before to write the full code, I try to make a test by reading the DEVID. For the value of DEVID, you are right, it was a mistake from me, it's 0xE5 the good value. So, if the test program is ok, I will write all the program.

Thanks for your help.

Michel

[Alice_Yang]

Hi Michel,

Yes , first check whether can read the DEVID data correctly .

Have a nice day !

Alice