Communication via SPI with L6470 in mode daisy chain

Posted on October 10, 2012 at 09:21

Hello

I've

gotten

the second

L6470

send data

by

SDO

.

I'm trying

to

execute the

MOVE

command

and

get

it to move

the engine

for the first

L6470

,

but I can not

make it move

the second

.

Can anyone

tell me

how I should

do to

send the commands

to the second

L6470

?.

Thank you.

Posted on October 16, 2012 at 10:33

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Posted on November 14, 2012 at 17:27

Hello,

I suggest you to check the CS line during the communication.

When N devices are connected in chain, the microcontroller must send N bytes at each communication cycle.

Your code seems ok, but are you sure the dSPIN_Nop and dSPIN_Write_Byte functions do not change the CS line status? In this case you are able to ''talk'' with the first device, but not with the second one and you are able to ''listen'' the second one, but not the first.

Kind Regards

Enrico

Posted on November 19, 2012 at 16:40

Hello.

Thanks for the reply

.

I have checked

that the functions

dsPIN_Nop and dsPIN_Write_Byte

only set to 0 the

CS

line, so use fflush() function to set it to 1

.

The writing

in

both engines

working properly

me

, but reading not get it to work

.

Regards.

Posted on November 20, 2012 at 09:57

The result

of reading is

always

0xffff.

Posted on November 20, 2012 at 10:02

Sorry,

I changed

the function

of

reading on

which I put

above.

The current

is

:

uint32_t dSPIN_Get_Param(uint_8 param, uint_16 niMotor)

{

    uint32_t temp = 0;

    uint32_t temp2 = 0;

    uint32_t rx = 0;

    uint32_t rx2 = 0;

    uint_16 ncI;

    /* Send GetParam operation code to dSPIN */

    if (niMotor==1) {

        temp2 = dSPIN_Write_Byte((uint8_t)(0x00));

        temp = dSPIN_Write_Byte(dSPIN_GET_PARAM | param);

    } else {

        temp2 = dSPIN_Write_Byte(dSPIN_GET_PARAM | param);

        temp = dSPIN_Write_Byte((uint8_t)(0x00));

    }

    fflush (sDrivers.spifd_6470);

    /* MSB which should be 0 */

    temp = temp << 24;

    rx |= temp;

    temp2 = temp2 << 24;

    rx2 |= temp2;

    switch (param)

    {

        case L6470_ABS_POS: ;

        case L6470_MARK: ;

        case L6470_SPEED:

            if (niMotor==1) {

                   temp2 = dSPIN_Write_Byte((uint8_t)(0x00));

                   temp = dSPIN_Write_Byte((uint8_t)(0x00));

            } else {

                   temp2 = dSPIN_Write_Byte((uint8_t)(0x00));

                   temp = dSPIN_Write_Byte((uint8_t)(0x00));

            }

            

            fflush (sDrivers.spifd_6470);

            temp = temp << 16;

            rx |= temp;

            temp2 = temp2 << 16;

            rx2 |= temp2;

        case L6470_ACC: ;

        case L6470_DEC: ;

        case L6470_MAX_SPEED: ;

        case L6470_MIN_SPEED: ;

        case L6470_FS_SPD: ;

        case L6470_INT_SPD: ;

        case L6470_CONFIG: ;

        case L6470_STATUS:

            if (niMotor==1) {

                   temp2 = dSPIN_Write_Byte((uint8_t)(0x00));

                   temp = dSPIN_Write_Byte((uint8_t)(0x00));

            } else {

                   temp2 = dSPIN_Write_Byte((uint8_t)(0x00));

                   temp = dSPIN_Write_Byte((uint8_t)(0x00));

            }

               fflush (sDrivers.spifd_6470);

            temp = temp << 8;

            rx |= temp;

            temp2 = temp2 << 8;

            rx2 |= temp2;

            

        default:

            if (niMotor==1) {

                   temp2 = dSPIN_Write_Byte((uint8_t)(0x00));

                   temp = dSPIN_Write_Byte((uint8_t)(0x00));

            } else {

                   temp2 = dSPIN_Write_Byte((uint8_t)(0x00));

                   temp = dSPIN_Write_Byte((uint8_t)(0x00));

            }

            

               fflush (sDrivers.spifd_6470);

            rx |= temp;

            rx2 |= temp2;

    }

    sDrivers.rx = rx;

    sDrivers.rx2 = rx2;

    

    return rx;

}

The result

of reading is

always

0xffff.

Thanks.

Posted on December 05, 2012 at 09:16

Hello,

from my understanding the firmware seems correct. I can only suggest you to check the physical level of the communication in order to verify if there is something wrong in the connections.

Regards

Enrico