Hi

I'm designing a power monitor and am going to have a portable display that stores various values over time. This is wirelessly connected to a detector circuit that uses a cs5463 ic.

My question is, would using eeprom be ok for writing to quite regulary. I'm planning to be able to show values that will be cumulative over time (around a months data or year if possible). It would be things like max current, cost of power over a week etc.

I beleive this will require a lot of re-writing data stored and have read that eeprom isn't great for this?

I'm using a PIC18F4520 and the eeprom I am looking at is the 25LC1024 from microchip.

The unit is going to battery powered so need non voltaile memory thats cheap. I was thinking that I could reduce the number of writes by storing the data in on chip memory then periodically write this to the eeprom so would only lose a bit of data.

Its only designed for use in domestic situation so accuracy isn't crucial so can afford to lose some data.

Thanks for your help

 

You might be interested in an outfit called Ramtron. They sell static memory products in both serial and parallel access. Mouser Electronics carries some of their stuff in their catalog (page 248). 4 meg (256 x 8) for $39.60.

 

Bit on the pricey side. Also am in UK and have to pay £16 to get it over here. Is static ram gona be the better choice than eeprom? I was hoping to spend no more than £2-3.

 

Also have limited number of pins so it will have to be a serial solution

 

hallo iam a new arab ingineering visitor and it is the first time to me to share and working on the net and i hope to find whomthey can helpe me to improve my experiences both in the net and high advanced electronics , thanks

 

Hi

I'm designing a power monitor and am going to have a portable display that stores various values over time. This is wirelessly connected to a detector circuit that uses a cs5463 ic.

My question is, would using eeprom be ok for writing to quite regulary. I'm planning to be able to show values that will be cumulative over time (around a months data or year if possible). It would be things like max current, cost of power over a week etc.

I beleive this will require a lot of re-writing data stored and have read that eeprom isn't great for this?

I'm using a PIC18F4520 and the eeprom I am looking at is the 25LC1024 from microchip.

The unit is going to battery powered so need non voltaile memory thats cheap. I was thinking that I could reduce the number of writes by storing the data in on chip memory then periodically write this to the eeprom so would only lose a bit of data.

Its only designed for use in domestic situation so accuracy isn't crucial so can afford to lose some data.

Thanks for your help

25LC1024 is quite slow in writing even a single byte (5ms approx.). If timing is not an issue that use of EEPROM would be fine. Otherwise, I would suggest serial Non-Volatile memory from Ramtron

Regards
Shoaib Ali

 

Hi

I'm designing a power monitor and am going to have a portable display that stores various values over time. This is wirelessly connected to a detector circuit that uses a cs5463 ic.

My question is, would using eeprom be ok for writing to quite regulary. I'm planning to be able to show values that will be cumulative over time (around a months data or year if possible). It would be things like max current, cost of power over a week etc.

I beleive this will require a lot of re-writing data stored and have read that eeprom isn't great for this?

I'm using a PIC18F4520 and the eeprom I am looking at is the 25LC1024 from microchip.

The unit is going to battery powered so need non voltaile memory thats cheap. I was thinking that I could reduce the number of writes by storing the data in on chip memory then periodically write this to the eeprom so would only lose a bit of data.

Its only designed for use in domestic situation so accuracy isn't crucial so can afford to lose some data.

Thanks for your help

If you are very tight on price and pins and also you want to stick to 24CXX series. Then one thing you implement circular stack. So you keep stacking up on new location when done you you can go back to first location and start over. You will get pretty good throughput from the chip.

 

Check the datasheet for the maximum number of erase/write allowable and you could calculate how long it is guaranteed to work.

Another option is to use serial flash, which is available in larger size, and priced lower than those expensive serial EEPROM. http://uk.farnell.com/jsp/search/browse.jsp?N=1000021+356668+356669+356670+382730+382769+382707+382710&Ns=PRICE_PLS_006_PRICE1|0