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VOliv.5
VOliv.5
Associate II
November 27, 2018
Question

How I do for receive data from a SPI EEPROM?

  • November 27, 2018
  • 1 reply
  • 1821 views

I'm using the STM32l053R8Tx, I configured the board NUCLEO-l053R8 by STM32CubeMX and I transmitted a data for an EEPROM with the function HAL_SPI_Transmit(...); and I'm trying receive the data with this function HAL_SPI_Receive(...); but I only receive " 0xFF 'ÿ' " as data. The memory that I use is that 25lc512, I send the instructions like the datasheet reported, but I can't receive another value, Can anybody help me?

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1 reply

Tesla DeLorean
Tesla DeLorean
Guru
November 27, 2018

Check the wiring and scope the signals. Ideally hook up a logic analyzer and review what you see at the pins. If the EEPROM is non-responsive you aren't going to get any usable data. Make sure the CS (chip select) pin is operational.

Easier to help if you provide a schematic and provide code.

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VOliv.5
VOliv.5Author
Associate II
November 28, 2018
void mem_start(void)
{
 HAL_GPIO_WritePin(M_CS_GPIO_Port, M_CS_Pin, GPIO_PIN_RESET);
 HAL_Delay(1);
 HAL_SPI_Transmit(&hspi2, &WREN, 1, 100);
 HAL_GPIO_WritePin(M_CS_GPIO_Port, M_CS_Pin, GPIO_PIN_SET);
 HAL_Delay(10); 
}
 
void send_data(unsigned int addr0, unsigned int addr1)
{
 mem_start();
 
 address = 0x01;
 
 uint8_t buffer[5];
 
 buffer [0] = 0x02;
 buffer [1] = 0x00;
 buffer [2] = address;
 buffer [3] = 0x03;
 buffer [4] = 0x06;
 
 HAL_GPIO_WritePin(M_CS_GPIO_Port, M_CS_Pin, GPIO_PIN_RESET);
 HAL_SPI_Transmit(&hspi2, buffer, 5,100);
 //HAL_Delay(5);
 HAL_GPIO_WritePin(M_CS_GPIO_Port, M_CS_Pin, GPIO_PIN_SET);
 HAL_Delay(10);
}
 
void receive_data(void)
{
 uint8_t buffer_in [3];
 uint8_t data[3];
 data [0] = 0x03; 
 data [1] = 0x00;
 data [2] = address;
 
//********************* receive data ***************************** 
 
 HAL_GPIO_WritePin(M_CS_GPIO_Port, M_CS_Pin, GPIO_PIN_RESET);
 HAL_SPI_Transmit(&hspi2, data, 3,100);
 HAL_SPI_Receive(&hspi2, buffer_in, 2,100);
 HAL_Delay(5);
 HAL_GPIO_WritePin(M_CS_GPIO_Port, M_CS_Pin, GPIO_PIN_SET);
 
//********************* transmit data *************************
 buffer_in [2] = buffer_in[0] | buffer_in[1];
 
 HAL_SPI_Transmit(&hspi1, &buffer_in[2], 1,100);
 HAL_GPIO_WritePin(LCLK_GPIO_Port, LAT_Pin, GPIO_PIN_SET);
 HAL_GPIO_WritePin(LCLK_GPIO_Port, LAT_Pin, GPIO_PIN_RESET);
}

0690X000006CXSaQAO.jpg Right, here it is the schematic (did on 'paint') and a part of my code that I use for the comunication with the EEPROM.

Tesla DeLorean
Tesla DeLorean
Guru
November 28, 2018

And does the signalling look right on the analyzer?

I'd perhaps use the TransmitReceive variant to send the command and dummy data, and be wary of the rising edge of the CS pin

See also SPI implementation in STM32Cube_FW_L0_V1.10.0\Drivers\BSP\STM32L0xx_Nucleo\stm32l0xx_nucleo.c

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