As5048a read encoder spi mode

[SDall]

hi I should read the value of the angle of the encoder as5048a via spi, the register has address 0x3fff, a 14-bit register, I tried in several but I failed, can you help me? I use a f401 !! thanks

[waclawek.jan]

What do you mean by "tried in several but I failed"? Show us what did you do, what was the expected behaviour and what was the observed one.

JW

[SDall]

i have tried :

HAL_SPI_Transmit(&hspi2,0x3fff,1,1000);

////// HAL_SPI_Receive(&hspi2,data,2,1000);

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

HAL_SPI_TransmitReceive(&hspi2,0x3fff,data,4,255);

data[0] = data[0] << 8;

  // result = data[1]| data[0];

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

digitalWrite(SS, LOW);

 //Reading 8 bit frame (the first half of 16-bit SPI transfer)

 result1 = SPI.transfer(0xfEEE);

 result1 &= 0b00111111;

 );

 result1 = result1 << 8;

 // getting last 8 bits (the last half of 16-bit SPI transfer)

 result2 = SPI.transfer(0xfEE);

 // merging

 result = result1 | result2;

with arduino no problem goes very well!

but with stm32 no,i don't undertand!

[SDall]

0X3FF sorry!

[SDall]

with arduino I receive the two bytes correctly and if I move the encoder I read the data, but with stm it always gives me the same number

[SDall]

word command = 0b0100000000000000;

command = command | 0X3FFF;

command |= ((word)spiCalcEvenParity(command)<<1;

byte right_byte = command & 0xFF;

byte left_byte = ( command >> 8 ) & 0xFF; SPI -

SPI.beginTransaction(settings);

digitalWrite(_cs, LOW);

SPI.transfer(left_byte);

SPI.transfer(right_byte);

digitalWrite(cs,HIGH)

digitalWrite(_cs, LOW);

left_byte = SPI.transfer(0x00);

right_byte = SPI.transfer(0x00);

digitalWrite(_cs, HIGH);

SPI.endTransaction();

return (( ( left_byte & 0xFF ) << 8 ) | ( right_byte & 0xFF )) & ~0xC000;}

[SDall]

i have founded the function with arduino for as5048a but i can't translate it!!!!

[turboscrew]

From the data sheet: "The 16 bit SPI Interface..." -> the size is always 2 bytes (or 16 bits).

You send two half words: The READ and the NOP (all-zero). During NOP the chip transmits the data.

You also need to calculate the parity. If the parity is wrong, I think the chip ignores the command.

The READ-command is 0x3FFF | 1 << 14 (read) | 1 << 15 (parity) = 0xFFFF