Steve Lawther's Data Logger Projects
Data Loggers are a speciality of mine - The aim for the 'blue-sky' projects is always to get as much storage capacity into as smaller a physical circuit using as little power as possible. Of course, designing data loggers for actual jobs, matching the data logger to the job in hand is more important.
My data logger Projects will be at the bottom of the page when I get around to finishing this page.
Possible storage Media / Chips
(lists not yet complete)
Removable Storage Media
There's a wealth of standard and proprietary removablable storage options nowadays. Possiblities include:-
For less than a few kilobytes
- SmartCards
For more than a Mbyte in Removable Storage - largest in size first:-
- PCCard (was PCMCIA) - A commodity item now, This is a Flash disk with a standard ATA / IDE interface. It is available in sizes from 10Mbyte to over 300 Mbytes, with 640Mbytes sampling. Older disks were 5 Volts, with newer PCCards able to also run at 3.3Volts. It's interface, being ATA / IDE, is a 64 way connector. Manufacturers include:-
- Compact Flash - A commodity item now, especially as it is used in 80%ish of digital cameras and in many HPCs. This is a Flash disk with a standard ATA / IDE interface, but in a smaller form factor that PCCard. It is available in sizes from 4Mbyte upto (currently) 48 Mbytes, and runs at either 3.3 or 5 Volts, but it's interface, being IDE, is a 50 way connector. If you data log onto compact flash using a DOS FAT protocol, adaptors are available to make the compact flash just like a disk drive, so you can read the disk into a PC without writing software. These include Sandisk ImageMate, which connects to a PC's parallel port, and various Compact Flash to PCCard adaptors, for use with laptop computers.
Manufacturers of Compact Flash disks include:-
- SmartMedia (also known as SSFDC) - A very small thin flash card, sized from 1MByte to 8MByte, used in some digital cameras. Although it has been avaliable for a while, it has not taken off yet, and chances of it becoming commodity is doubtful.
This is a Flash card version of NAND Flash chips, and has a 22 contact interface, requiring upto 60mA at 5 or 3.3Volt. Adaptors are available to make to make SmartMedia just like a PCCard, or like a Floppy disk, so you can read the disk into a PC without writing software.
More Info at the The SmartMedia Forum
Manufacturers of SmartMedia cards include:-
- Toshiba - The
- Samsung
- Nat Semi also did Smart Media, but pulled out when it didn't take off
- MultiMediaCard - A new very small thin flash card, sized from 2MByte to 16MByte, used in some mobile phones, and HPCs. As it is new into the market, whether will become commodity is unknown.
This is a Flash card with a 7 contact interface that can be both MMcard bus, and SPI bus. The latter bus makes it a good bet for low I/O count microcontrollers. Also it is harder to break than the smartmedia cards( which are too thin for their size). It is currently only made by Sandisk. (Siemens does a Mask ROM version, and there's a rumour Sony is a second source, but I haven't checked this out for myself yet.)
- ISSI make a SPI bus card similar in size to a SIM card, with a smartcard like 6 contact SPI bus interface. Sized from 512KByte to 4MByte, I haven't seen any large uses of this card yet, so its take-up is unknown.
Projects
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Steve Lawther
Last Updated by Steve Lawther on Tuesday, 27 October, 1998 at 7:32 PM.
