SparkFun Forums

[jandirks]

It would be nice if there was a possibilty to log the gps data comming from the new EM-406 or ET-301 gps devices on a SD Card.

Would it be hard to do something like that? I guess a PIC with some software is needed to accomplish this?

JD

[sparky]

There is always a way. But things get nasty.

You can setup a PIC to record to the SD card directly. But SD requires that you write to it in 512 byte blocks. Since most PICs have under 300bytes of ram, this is too much for normal PICs. I recommend using an ARM or the common work around is to use an external SPI EEPROM or I2C EEPROM to temporarily store the GPS data until you hit a 512 block and then record this block to SD. Not great, but we've based a few projects on this pricipal.

-Nathan

[MGP]

Or use a mid-range MSP430. They run at 3.3V, have excellent analog peripherals and can have 1K-2K of RAM.

[jandirks]

Thanks for your replies!

Probably this is going to be way over my head. I have a programming background (windows), so this wouldn't be the hard bit if I decide to dive into it, the hardware bit is what worries me. I would need a lot of help for this.

I have been looking on the SFE website and found this I2C eeprom and this link. Maybe this is a start.

[Caffeine]

How about compact flash?

There's a free library on www.avrfreaks.com for the AVR microcontroller to write FAT32 stuff toa CF card...