why i am i not able to write anything on 24LC356 eeprom

RE: why i am i not able to write anything on 24LC356 eeprom

Jørgen Holmefjord — Wed, 12 Apr 2017 08:53:46 GMT

Sorry, my bad. The line in read32 should be

result = (pbuf[0] << 24) | (pbuf[1] << 16) | (pbuf[2] << 8) | (pbuf[3]);

RE: why i am i not able to write anything on 24LC356 eeprom

jay — Tue, 11 Apr 2017 16:33:22 GMT

I am getting 0 as out put I tried the following code. I call eepron_test function

void AT24C512_WriteBytes(uint16_t addr, uint8_t *pbuf, uint16_t length)
{
    Wire.beginTransmission(addrr);
    Wire.write( (uint8_t)addr>>8 );
    Wire.write( (uint8_t)addr );
    Wire.write(pbuf, length);
    Wire.endTransmission();
}
 
void AT24C512_ReadBytes(uint16_t addr, uint8_t *pbuf, uint16_t length)
{
    Wire.beginTransmission(addrr);
    Wire.write( (uint8_t)addr>>8 );
    Wire.write( (uint8_t)addr );    
    Wire.endTransmission();
       
    Wire.requestFrom(addr+1, length);
    while( Wire.available() > 0 )
    {
        *pbuf = Wire.read();
        pbuf++;
    }
}
void write32(uint16_t addr, uint32_t value)
{
    uint8_t pbuf[4] = {value >> 24, value >> 16, value >> 8, value};
    AT24C512_WriteBytes(addr, pbuf, sizeof(pbuf));
}

uint32_t read32(uint16_t addr)
{
    uint32_t result;
    uint8_t pbuf[4];
    AT24C512_ReadBytes(addr, pbuf, sizeof(pbuf));
    result = (pbuf[0] << 24) & (pbuf[1] << 16) & (pbuf[2] << 8) & (pbuf[3]);
    lcd.clear();sa
                lcd.setPosition(0,1);
        lcd.printf("%d", result);
        
        return result;
    
}

void eeprom_test() {
    Wire.begin(P0_8, P0_10, TWI_FREQUENCY_100K);
   write32(addrr, test);
   read32(addrr);
   wait(6);

}

RE: why i am i not able to write anything on 24LC356 eeprom

Jørgen Holmefjord — Tue, 11 Apr 2017 11:24:04 GMT

Did you solve your initial problem? I have not tested this, but you should be able to write and read 32-bit words similar to this:

void write32(uint16_t addr, uint32_t value)
{
	uint8_t pbuf[4] = {value >> 24, value >> 16, value >> 8, value};
	AT24C512_WriteBytes(addr, pbuf, sizeof(pbuf));
}

uint32_t read32(uint16_t addr)
{
	uint32_t result;
	uint8_t pbuf[4];
	AT24C512_ReadBytes(addr, pbuf, sizeof(pbuf));
	result = (pbuf[0] << 24) | (pbuf[1] << 16) | (pbuf[2] << 8) | (pbuf[3]);
	return result;
}

RE: why i am i not able to write anything on 24LC356 eeprom

jay — Fri, 07 Apr 2017 20:05:41 GMT

This code is told by rdbear labs to use for I2c. Can you please tell me how can I modify it to write and read an uint32_t value.

RE: why i am i not able to write anything on 24LC356 eeprom

jay — Fri, 07 Apr 2017 20:04:44 GMT

#include "mbed.h"
#include "wire.h"
 
#define BLE_Nano
//#define nRF_51822
 
 
#ifdef nRF_51822
#define SCL         28
#define SDA         29
#endif
 
#ifdef BLE_Nano
#define SCL         7  
#define SDA         6
#endif
 
#define DEV_ADDR    0xA0
 
Serial pc(USBTX, USBRX);
TwoWire Wire = TwoWire(NRF_TWI0);
 
void AT24C512_WriteBytes(uint16_t addr, uint8_t *pbuf, uint16_t length)
{
    Wire.beginTransmission(DEV_ADDR);
    Wire.write( (uint8_t)addr>>8 );
    Wire.write( (uint8_t)addr );
    Wire.write(pbuf, length);
    Wire.endTransmission();
}
 
void AT24C512_ReadBytes(uint16_t addr, uint8_t *pbuf, uint16_t length)
{
    Wire.beginTransmission(DEV_ADDR);
    Wire.write( (uint8_t)addr>>8 );
    Wire.write( (uint8_t)addr );    
    Wire.endTransmission();
       
    Wire.requestFrom(DEV_ADDR+1, length);
    while( Wire.available() > 0 )
    {
        *pbuf = Wire.read();
        pbuf++;
    }
}
 
 
static uint8_t wt_data[10] = {'H', 'e', 'l', 'l', 'o', 'W', 'o', 'r', 'l', 'd'};
static uint8_t rd_data[10];
 
static uint16_t index;
 
int main(void)
{
    pc.baud(9600);
    wait(5);
    //Wire.begin();
    Wire.begin(SCL, SDA, TWI_FREQUENCY_100K);
    pc.printf("IIC Demo Start \r\n");
    
    AT24C512_WriteBytes(0, wt_data, 10);
    wait(0.1);
    
    while(1)
    {
        AT24C512_ReadBytes(0, rd_data, 10);     
        pc.printf("Read data from AT24C512 \r\n");
        for(index=0; index<10; index++)
        {
            pc.putc(rd_data[index]);
            rd_data[index] = 0x00;
        }
        pc.printf("\r\n");
        wait(1);
    }
}

RE: why i am i not able to write anything on 24LC356 eeprom

jay — Fri, 07 Apr 2017 20:01:50 GMT

response is the char I am trying to use.

RE: why i am i not able to write anything on 24LC356 eeprom

jay — Fri, 07 Apr 2017 20:00:58 GMT

the value i want to save is 1000 as mentioned in the code. I dont know what is wrong in my code. If I use wire.h the value I get is a nine digit number.

RE: why i am i not able to write anything on 24LC356 eeprom

Jørgen Holmefjord — Thu, 06 Apr 2017 08:42:56 GMT

Do you mean that you get "address 65355" on the LCD? What is the values of response[0] and response[1]?