[SOLVED] Relay switching counter and Display on LCD using 8051

[prabhakar06447]

I am designing a digital counter using 89c2051 or 89c51 and 16x2 LCD Display and relay for switching purpose.

How to get the previous counter value of microcontroller when there is a sudden power-cutoff or power failure to the device.

I want the count value present at the time of power failure..

Anyone help in designing this counter.

Thanks......

 

[milind.a.kulkarni]

best way to do this wirite your counter values to some external memory like EPROM and on power up or power -down read correponding values.....I am considering your using same supply voltage to power up the 89c51 only the thing is that you need write some I2C or some alike interface

 

[prabhakar06447]

yes i am using only one power supply for muc.
I would like to use EEPROM 24c02, how to interface it to microcontroller.
please provide C code to read and write the data from EEPROM 24C02.

 

[ark5230]

For short duration power failure, a battery backup is the easiest solution, capabilities of microcontroller allow sizable durations.

 

[prabhakar06447]

battery backup is good solution but i want to use this with eeprom..
what are the command to store and retrieve the data from eeprom...

any suggestions please..

 

[milind.a.kulkarni]

Please refer the link bellow there are some I2C driver are there may be helpful to you -
Microchip PIC micros and C - source and sample code
Good Luck

 

[prabhakar06447]

The link you shared is useful. I am going through...
Can you share any content that explain 8051 with Hi-Tech C compilers

 

[milind.a.kulkarni]

I think Keil website is good for that also you can refer and download some of the stuff from website bellow-
Projects - Free 8051 Microcontroller Projects
News : 8051 Microcontroller Projects AVR PIC Projects Tutorials Ebooks Libraries codes
8051 i2c code : 8051 Microcontroller Projects AVR PIC Projects Tutorials Ebooks Libraries codes
Good Luck

 

[prabhakar06447]

Hello,

can we use Proteus ISIS to simulate and verify the function of AT24cxxx EEPROM with 8051 MUC.

 

[prabhakar06447]

Hello,

I am struck with my coding to store the data into the 24c02 and reading it.

Using this code i am only able to read and store the first digit (i.e k= a[0]), and getting random numbers for other digits like l=a[1].......

I am using proteus and HI-Tech compiler
for(i=0; i<4; i++)
{
a=ReadBYTE(0x01);
}
k=a[0]; tmpd1 = k; ///a[] is char type
l=a[1]; tmpd2 = l;
.......

while(1)
{
for(j=0;j<10;j++)
{ //units
if(!SW1)
{ delay(500);
while(!SW1){delay(10);}
k++;
commandsend(0xCF);
tmpd1++;
delay(10);
sendcount(str[k]);
WriteBYTE(0x001, k);
commandsend(0x8F);
}
}
//Tens place
if(tmpd1 >=10)
{
tmpd1 =0; k=0; l++, tmpd2++;
delay(10);
commandsend(0xCE);
delay(10);
sendcount(str[l]);
WriteBYTE(0x002, l);
commandsend(0x8E);
}
......................
}

 

[prabhakar06447]

Any one please find-out errors in my code.........