Problem connecting SPI to

[CK.3]

I am new to STM32. I am porting my code from ATMega128 to STM32 for faster thru put . I have to connect W5500 to STM32F103 on SPI2.

To test my understanding of SPI on STM32 after compiling , a small test code in while loop.

 SPI_Write(S0_CR,CR_CLOSE); //#define S0_CR 0x0001, CR_CLOSE 0x10;

data_read = SPI_Read(S0_CR);

used the below sub functions

void SPI_Write(int addr,char data)

{

SPI_select

HAL_SPI_Transmit(&hspi2, ((addr & 0xFF00) >> 8), 1, 100);

HAL_SPI_Transmit(&hspi2, (addr & 0x00FF),1,100);

HAL_SPI_Transmit(&hspi2, (WRITE_OPCODE_S0),1,100);

HAL_SPI_Transmit(&hspi2, data, 1, 100);

SPI_deselect

}

char SPI_Read(int addr)

{

SPI_select

HAL_SPI_Transmit(&hspi2,((addr & 0xFF00) >> 8),1,100);

HAL_SPI_Transmit(&hspi2,(addr & 0x00FF),1,100);

HAL_SPI_Transmit(&hspi2,(READ_OPCODE_S0),1,100);

HAL_SPI_Receive(&hspi2,spi_rec,1,100);

SPI_deselect

return spi_rec;

}

Expected 0x10 (16) in data_read but got zero. thru UART. Tried diagnosing with

if(Err !=HAL_OK)

SPI_Write works to HAL_OK when first line address is not 0x00;

DSO Shows no SCK pulses when it is 0x00 though CS goes low.

Similarly in SPI_Read; line -- HAL_SPI_Receive(&hspi2,spi_rec,1,100); gives !=HAL_OK on UART

My proceeding further depends on clearing these doubts. Request help please.

[TDK]

> HAL_SPI_Transmit(&hspi2, ((addr & 0xFF00) >> 8), 1, 100);

> HAL_SPI_Transmit(&hspi2, (addr & 0x00FF),1,100);

> HAL_SPI_Transmit(&hspi2, (WRITE_OPCODE_S0),1,100);

> HAL_SPI_Transmit(&hspi2, data, 1, 100);

It looks like you're trying to send raw data in the first 3 function calls and a pointer to data in the last call. That's not how this function works. You need to provide a pointer to data. One way to do that is the following:

uint8_t value = (addr & 0xFF00) >> 8;
HAL_SPI_Transmit(&hspi2, &value, 1, 100);
value = addr & 0x00FF;
HAL_SPI_Transmit(&hspi2, &value, 1, 100);
value = WRITE_OPCODE_S0;
HAL_SPI_Transmit(&hspi2, &value, 1, 100);

It's unclear how data and spi_rec are defined.

[CK.3]

Thanks for the response.

data_read and spi_rec have been declared as char.

Tried the method recommended on SPI_Read(S0_SR) but always gives Zero. S0_SR being the Socket Status Register where Zero could mean Socket closed or no value.

Still unable to resolve.

[TDK]

The code you posted should give you compiler errors. The second argument needs to be a pointer, not a char.

error: invalid conversion from 'char' to 'uint8_t* {aka unsigned char*}' [-fpermissive]
   HAL_UART_Transmit(nullptr, data, 1, 100);
                                          ^

[CK.3]

No Such compiler error threw up. However on your advice declared : uint8_t *spi_rec ;

To track the fault, changed the two sub-functions with if(err != HAL_OK) and used UART1 to check for any error.

if(err != HAL_OK) on the first line of both functions were avoided since the addr only contains 0x00 were no SCK pulses appear on DSO

void SPI_Write(int addr,char data)

{

char err;

SPI_select //HAL_GPIO_WritePin(GPIOB, GPIO_PIN_12, GPIO_PIN_RESET);

uint8_t value = (addr & 0xFF00) >> 8;

err = HAL_SPI_Transmit(&hspi2, &value, 1, 100);

value = addr & 0x00FF;

err = HAL_SPI_Transmit(&hspi2, &value, 1, 100);

if(err != HAL_OK)

{

 strcpy(tx_buf,"Tx2 ? \r\n");

}

else

{

value = (READ_OPCODE_S0);

err = HAL_SPI_Transmit(&hspi2, &value, 1, 100);

if(err != HAL_OK)

{

strcpy(tx_buf,"Tx3 ? \r\n");

}

else

{

value = data;

err = HAL_SPI_Transmit(&hspi2,&value, 1, 100);

if(err != HAL_OK)

{

   strcpy(tx_buf,"Tx4 ? \r\n");

}

else

sprintf(tx_buf,"Tx All OK data %d \r\n",data);

}

}

SPI_deselect

HAL_UART_Transmit(&huart1,tx_buf,strlen(tx_buf), 100);

}

uint8_t SPI_Read(int addr)

{

uint8_t err;

SPI_select //HAL_GPIO_WritePin(GPIOB, GPIO_PIN_12, GPIO_PIN_RESET);

uint8_t value = (addr & 0xFF00) >> 8;

err = HAL_SPI_Transmit(&hspi2, &value, 1, 100);

value = addr & 0x00FF;

err = HAL_SPI_Transmit(&hspi2, &value, 1, 100);

if(err != HAL_OK)

{

 strcpy(tx_buf,"Rx2 ? \r\n");

}

else

{

value = (READ_OPCODE_S0);

err = HAL_SPI_Transmit(&hspi2, &value, 1, 100);

if(err != HAL_OK)

{

strcpy(tx_buf,"Rx3 ? \r\n");

}

else

{

err = HAL_SPI_Receive(&hspi2,spi_rec, 1, 100);

if(err != HAL_OK)

{

   strcpy(tx_buf,"Rx4 ? \r\n");

}

else

sprintf(tx_buf,"Rx All OK %d \r\n",spi_rec);

}

}

SPI_deselect

HAL_UART_Transmit(&huart1,tx_buf,strlen(tx_buf), 100);

return spi_rec;

}

The while loop now had:

SPI_Write(S0_CR,CR_LISTEN); // CR_LISTEN

 sockstat = SPI_Read(S0_SR); //#define S0_SR

where

#define S0_CR   0x0001   // Socket 0: Command Register Address in W5500

#define S0_SR   0x0003   // Socket 0: Status Register Address

#define CR_LISTEN    0x02  // Wait connection request in tcp mode(Server mode)

The Br@y Terminal showed:

Tx All OK data 2 

Rx4 ? 

Tx All OK data 2 

Rx4 ? 

Tx All OK data 2 

Rx4 ? 

I changed SPI2 configuration in GPIO settings of PB14 (MISO), though in input mode to Pull up --if anything changed in HAL_SPI_Receive ------Nothing changed.

Rx4 ? ------------------------still.

Just going in circles.

[TDK]

Maybe start with figuring out why your compiler is silently converting (char) to (uint8_t *) without errors. Then correct the usages of HAL_SPI_Receive where you're still passing a char.

> I changed SPI2 configuration in GPIO settings of PB14 (MISO), though in input mode to Pull up

Relevant SPI pins should be in AF mode.

If HAL_SPI_Receive isn't returning HAL_OK, what is it returning instead? It should not be a mystery. Figure out the return code and use that to help debug.

[CK.3]

With Regards to your 2nd line, SPI2 set up --- PB14(MISO) always showed up as GPIO mode to Input while MOSI and SCK showed up as AF. Only I had changed to Pull up.

Now reverted back to No pull up or down . Should the MISO also show up as AF ?. ( which I am unable to change to AF)

As per your instructions, error in HAL_SPI_Receive is returning 1 which is HAL_ERROR. My understanding is { HAL_OK = 0x00U, HAL_ERROR = 0x01U, HAL_BUSY = 0x02U, HAL_TIMEOUT = 0x03U }; --- on google search.

Regards to your first Line-- Compiler silently converting  (char) to (uint8_t *) without errors. Since I don't know how to go about it, I just converted Char to uint8_t

Problem not yet solved. Thanks for the quick response.

[CK.3 · Accepted solution]

The problem is solved.

The error was because I did not add a Ampersand & prefixed to uint8_t spi_rec in HAL_SPI_Receive(&hspi2, &spi_rec,1,100)

Now the HAL_OK comes thru till the last stage successfully thru UART.

Thanks a ton