data saved on external EEPROM SPI 25LC020A are not read correctly
I can write and read byte, float or text on the eeprom. And I was thinking that is Ok with the processes of wiriting and reading. But when I tried that with the group of data, it appeared that something is wrong. It means that when I first write goup of data, fx seven bytes and then I try read them, it appears that only about half of them are correct. Fx:
bytes written:
Test byte to write into EEPROM: spi_buf = 0xA0
Test byte to write into EEPROM: spi_buf = 0xA1
Test byte to write into EEPROM: spi_buf = 0xA2
Test byte to write into EEPROM: spi_buf = 0xA3
Test byte to write into EEPROM: spi_buf = 0xA4
Test byte to write into EEPROM: spi_buf = 0xA5
Test byte to write into EEPROM: spi_buf = 0xA6
Bytes read:
Test byte read: 0xA0
Test byte read: 0xAF
Test byte read: 0xA2
Test byte read: 0x0
Test byte read: 0xA4
Test byte read: 0xA4
Test byte read: 0xA6
The same concerns other type of data.
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The code written under stm32CubeIDE, board F103C8T6.
SPI configuration:
Full-Duplex Master
NSS Signal Type
Data Size - 8 Bits
First Bit - MSB First
Prescaler(for baud rate) - 64 (Baud Rate = 1.125 Mbits/s)
CPOL - LOW
CPHA - 1 Edge
// EEPROM SPI 25LC020A is 8 bit adressing (as read in datasheet).
Changing clock frequency or inserting delays for CS or transmitting functions did not help.
Does anyone know how to fix this ????
void EEPROM_Write_Byte(uint16_t address, uint8_t data)
{
EEPROM_Write_Enable();
uint8_t cmd[3];
cmd[0] = 0x02; // command Write
cmd[1] = (address >> & 0xFF;
cmd[2] = address & 0xFF;
HAL_GPIO_WritePin(GPIOA, GPIO_PIN_4, GPIO_PIN_RESET); // CS low
HAL_SPI_Transmit(&hspi1, cmd, 3, HAL_MAX_DELAY);
HAL_SPI_Transmit(&hspi1, &data, 1, HAL_MAX_DELAY);
HAL_GPIO_WritePin(GPIOA, GPIO_PIN_4, GPIO_PIN_SET); // CS high
HAL_Delay(10);
EEPROM_Wait_For_Ready();
}
uint8_t EEPROM_Read_Byte(uint16_t address)
{
uint8_t data;
uint8_t cmd[3];
cmd[0] = 0x03; // command Read
cmd[1] = (address >> & 0xFF;
cmd[2] = address & 0xFF;
HAL_GPIO_WritePin(GPIOA, GPIO_PIN_4, GPIO_PIN_RESET); // CS low
HAL_SPI_Transmit(&hspi1, cmd, 3, HAL_MAX_DELAY);
HAL_SPI_Receive(&hspi1, &data, 1, HAL_MAX_DELAY);
HAL_GPIO_WritePin(GPIOA, GPIO_PIN_4, GPIO_PIN_SET); // CS high
return data;
}
void EEPROM_Write_Enable(void)
{
uint8_t cmd = 0x06; // command Write Enable
HAL_GPIO_WritePin(GPIOA, GPIO_PIN_4, GPIO_PIN_RESET); // CS low
HAL_SPI_Transmit(&hspi1, &cmd, 1, HAL_MAX_DELAY);
HAL_GPIO_WritePin(GPIOA, GPIO_PIN_4, GPIO_PIN_SET); // CS high
HAL_Delay(5);
}
void EEPROM_Write_Float(uint16_t address, float data)
{
EEPROM_Write_Enable();
uint8_t cmd[3];
cmd[0] = 0x02; // command Write
cmd[1] = (address >> & 0xFF;
cmd[2] = address & 0xFF;
uint8_t* dataBytes = (uint8_t*)&data;
HAL_GPIO_WritePin(GPIOA, GPIO_PIN_4, GPIO_PIN_RESET); // CS low
HAL_SPI_Transmit(&hspi1, cmd, 3, HAL_MAX_DELAY); // sending command and adress
HAL_SPI_Transmit(&hspi1, dataBytes, sizeof(float), HAL_MAX_DELAY); // data send
HAL_GPIO_WritePin(GPIOA, GPIO_PIN_4, GPIO_PIN_SET); // CS high
HAL_Delay(10);
}
float EEPROM_Read_Float(uint16_t address)
{
float data;
uint8_t cmd[3];
uint8_t* dataBytes = (uint8_t*)&data;
cmd[0] = 0x03; // command Read
cmd[1] = (address >> & 0xFF;
cmd[2] = address & 0xFF;
HAL_GPIO_WritePin(GPIOA, GPIO_PIN_4, GPIO_PIN_RESET); // CS low
HAL_SPI_Transmit(&hspi1, cmd, 3, HAL_MAX_DELAY); // sending command and adress
HAL_SPI_Receive(&hspi1, dataBytes, sizeof(float), HAL_MAX_DELAY); // data read
HAL_GPIO_WritePin(GPIOA, GPIO_PIN_4, GPIO_PIN_SET); // CS high
return data;
}
void saveFloats() {
for (uint16_t i = 0; i < 7; i++) {
uint16_t address = i * sizeof(float);
float value = (i + 1) * 3.14f; // value to save
EEPROM_Write_Float(address, value);
EEPROM_Wait_For_Ready();
HAL_Delay(100);
printf("%2d: Adress: %3d, float to save: %6.3f\n", i, address, value);
}
printf("\n");
}
void readFloats() {
uint16_t address;
float readValue;
for (uint16_t i = 0; i < 7; i++) {
address = i * sizeof(float);
readValue = EEPROM_Read_Float(address);
EEPROM_Wait_For_Ready();
HAL_Delay(100);
printf("%2d: Adress: %3d, read float: %6.3f\n", i, address, readValue);
}
printf("\n");
}
void save_read_float()
{
for (uint16_t i = 0; i < 7; i++)
{
uint16_t address = i * sizeof(float);
float value = (i + 1) * 3.14159f; // value to save
EEPROM_Write_Float(address, value);
HAL_Delay(10);
printf("%2d: Adres: %3d, float to save: %6.3f\n",i, address, value);
float readValue = EEPROM_Read_Float(address);
printf("%2d: Adres: %3d, read float directly after 10ms: %6.3f\n",i, address, readValue);
} printf("\n\n");
}
int main()
{
save_read_float();
saveFloats();
HAL_Delay(1000);
readFloats();
return 0;
}