USB/Serial Data Input Device ??

"InOverMyHead" schreef in bericht news:fOktb.1124$ snipped-for-privacy@newsread2.news.pas.earthlink.net...

sense

Bob,

What you want to do is known as data logging. A cheap (in components) solution is using the parallel port. You get whatever sensorvoltage you have, take an AD-converter to make it 8 bits binary and present it to the parallel port. The burden of timing is on the side of the PC-program. That's to say on the programmer. If you use DOS it is not that difficult but it's hardly possible to use the PC for somthing else at the same time. If you're using windows, the programming of the parallel port is a pain. Furthermore, the timing (especially for short intervals) is not very accurate as windows has a lot of other things to do.

A much better solution is taking a microcontroller. Use one that has a uart and a AD-converter on board. The micro can gathering the data and send it to the PC which can take all the time it needs to receive and store it. Windows can be programmed to perform this task in the background, so you can use the PC for normal tasks as well.

I'm sure you can find a lot of info googling for data logging.

petrus

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In article , snipped-for-privacy@hccnet.nl mentioned...

People overlook using the game port to do simple analog input. You can put a 30k ohm thermistor across the pins that normally have the joystick pots, and read the thermistor value, and translate that into temperature. Or use a CdS photocell instead of the thermistor to sense light (radio snack has them). You can put a switch across the joystick button pins to get an on/off input. This is probably the least expensive way.

You can buy a DMM from radio shark that connects to the PC thru a serial port. It comes with software that allows you to read the voltage or current or resistaince, etc. For more info see URL

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sense

What you need is a 'Labjack'.

USB powered and you can daisy-chain them too. HTH, JB

or

Tom Woodrow

Try

for the DI-194R3 DA at $24.95, then select your input type.

GL Tom

sense

and

talking

great.

solutions?

Bob,

B&B Electronics has an analog to serial module for about $70 US Kind of experience

DLPDesign has a USB example design with a DS18S20 Temperature sensor for $50. With the driver from FTDIchip.com, you can access this using a virtual comm port. (serial).

If you need to import serial to Excel, I can provide an example spreadsheet that uses Excel macros (VBA) and the MSComm Control, which is available on the Net. Drop me a line if you are interested.

If you want to build something, KitsRUS has a datalogger kit:

Hobby Engineer sells this kit for $29.

snipped-for-privacy@yahoo.com

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - >What am I looking for? I don't even know what to call it. But it would sense

At least on the old ISA bus gameport adaptors, and those integrated on older I/O cards (the 558 based ones), there is less than 8 bits, when you reslove out the play in the A/D convertor used.

Try the intro level serial ADC from DATAQ Instruments

It has four 10 bit, +/-10 volt ADC channels and two digital channels for control. It comes with Windows software so you can use it as a chart recorder. I spent a number of hours exploring ways to measure light and temperature with it. If you do any programming, an ActiveX control is included so you can access the unit from Visual Basic or VBA (in Excel, Access, etc).

You can read about the unit here:

It's US$25 and I think it's worth the money just for the data acquisition education you'll get while exploring it.

More about me:

VB3/VB6/NSBasic Palm/C/PowerBasic source code: Drivers for Pablo graphics tablet and JamCam cameras: johnecarter at@at mindspring dot.dot com. Fix the obvious to reply by email.

Try these links...

sense

sense

How about the Maxim DS1615, a one chip temperature recorder. You can dump the values to the serial port later.

Wim

Wow - you guys are great. I'm going with the Hobby Electronics' K145 Temp Data Logger kit. Thanks again for all the leads. I've spent HOURS getting happily sidetracked. Oh the possibilities . . .

Bob

sense

Yes, this is generally called "data logging", and there are getting to be thousands of ways of doing it. If you don't want to dedicate a desktop or laptop computer to the job, you can buy dedicated loggers that do their thing for minutes to years, after which you download the data to a computer. Onset

makes self-contained loggers for a wide variety of variables (temp, light, humidity, events, voltage, etc.) for both dry and wet conditions. They're rugged, relatively cheap, last forever, and are a breeze to use. If you are serious, with serious money, you can go to companies such as Campbell Scientific but that's outside the realm of "hobby". One thing I want to explore is using a cheap Palm organizer (Palm IIxe's are getting cheap on eBay) and something like the "MELD" data acquisition board ) to log, say, four channels of temperature over a period of months. National Semiconductor makes the LM34 and LM35 temperature-to-voltage converters, available through DigiKey for cheap, and you could instrument your house (or compost pile or whatever) for less than $100.