data logger storage devices ?

[fireplus]

hi,

i want to make an embedded gps data logger , so my frist choise was eeprom serial memory but most are rated for between 1 million to 10 million erase/writes, which is not efficent for a long time (ex:1 year) products so i think in the flash memory but are the flash memory suffer from the same disadvantages of the eeprom or what ??
can any body suggest on me what kind of storage devices can i use .

thanks for any body wants to help

Fire in the Wire :sm2:

 

[pisoiu]

Hi,
One million erase/write cycle per year means you can erase/write every cell over 2700 times each day. Isn't that enough ? If still not enough, use large memories ( ex. at45db family from www.atmel.com ) and use a rolling algorythm, thus ensuring a less usage of the memory area. It will last longer.

/pisoiu

 

[Hero]

Hi,

I suggest some NV RAM option. My recomendation is to use low-power SRAM with backup lithium battery and approriate MAXIM IC with reset and battery backup function. Also if you don't need extremely speed design use CE output from MAXIM IC for SRAM CE input to prevent data coruption during power-fall. In this case you don't need additional circuit to prevent power-fail and data coruption.

Every EEPROM technology suffer form data coruption in case of write during power-fail. To protect data you need additional hardware and software protection (NMI interrupt before power fail), also you have limits for number of writes.

Regards

 

[marie65]

Check FRAM memories from www.ramtron.com. You can ask for samples for serial and paralel NV memories with high Endurance 1 Trillion Read/Writes, that are direct replacement of usual EEPROMs

 

[mrcube_ns]

For those purpose I use classic RAM memory with battery back up. If you detected power fail (you have to have some kind of UPS), then copy data from RAM to flash.

Regards.

Mr.Cube

 

[fireplus]

hi,

thanks for every body try to help me

can i use MMC flash memory (spi mode)?

could you explain what ups is ?

Fire in the Wire :sm2:

 

[Bukitoo]

Hi! I have a similiar project on my hands.
I don't need (hopfuly) a year of storage. I need just 3 months.
I've made a study of all technologies, and I wonder which one to use.
I'm between using a SRAM (parallel, with a port serial expansion) and a serial Flash. Actually Flash Memory sounds better to me, because I don't have to use a backup battery and some components. Another adventage is that I don't need to use the port expansion. The problem is that I have only page mode writes (and I need to store all the data whitout loosing writes cycles)

Should I use another technology ? NVRAMS are veeery expensive. I consider to use a SD memory card, but is expesive also, and I don't need that amount of storage.

Thanks in advance.

 

[Rafael]

@fireplus

UPS = Uninterruptible Power System

I´d suggest MMC/SD cards for your project...

check this page:
www.captain.at/electronics/pic-mmc/

 

[mc&fpga]

why you don't use the sdram memory as you know it uses in pc
and for life guarantee .

 

[Bukitoo]

SDRAM memory needs refresh, so it more difficult to make it work (in addition that i've never use it). I don´t know which is its power comsumption performance. I have the idea that if the memory needs refresh, it needs a clock and therefore it consumes a little more than a sram.

 

[scarecrow_here]

Hi,
I suggest SD/MMC. It is flexible, simple hardware design, cheap, and there are a lots of MCUs has SPI interface. The program implementation is easy.

 

[fireplus]

hi,

i found a finel solution for this proplem i use mmc with eeprom as the 512byte backup in case of power loss

Thank you all

 

[artem]

Dont forget that almost all mmc's has less write/erase endurancy than eeprom . And also by software you can increase endurance of eeprom as described in AN from Atmel for AVR microcontroller .

 

[Kolia]

Hi

How ist organizotion FAT system in DataFlash or other file system

thanks

 

[bigmelon]

@fireplus

UPS = Uninterruptible Power System

I´d suggest MMC/SD cards for your project...

check this page:
www.captain.at/electronics/pic-mmc/

For "UPS", maybe there's other meaning which is total different from "Uninterruptible Power System", it stands for the international carrier, UPS, as famous as FedEx, DHL, TNT

 

[sensor_ua]

I use the FRAM FM24 series from Ramtron to buffer datablocks before writing to DataFLASH AT45 series (Atmel) or MMC-Card. For FLASH the endurance must be calculated for Erase-Write cycles, not for Write-only cycles. Erase do for BLOCK data and number of Erase (cycles) is smaller then number of bytes. The AT26 series of DataFLASH have biggest size of blocks for Erase them AT45.