Frequency to Voltage Conversion

cjp4627 · Post by **cjp4627** » Mon Sep 15, 2008 8:22 pm

Hey Guys,

Very new at this and I am getting ready to order my first arduino. I have been doing tons of reading and I have a few projects in mind.

First project-

I would like to take the signal from a VR sensor (ABS sensor in this case) and use a look up table on the ardunio to convert it to a linear voltage output. This would be in turn used as an input into an EMS. I realize that this could be done strictly with analog hardware but I want to give it a shot with the Arduino first and get my feet wet.

Second Project -

I want end up recieving and logging the data from my EMS for later analysis. I know that all I have to do is send it an "a" followed by a binary number to tell it what data I want. Then it will send me back all the raw binary data which I want to log. My question is, how well can I store this raw data on to a removeable storage medium such as an SD card or the like.

I know that the second project is getting a little deep for a beginner but when I have something that interests me, it will help keep me focused and determined. I appreciate any and all input and advice you guys have to offer me.

Thanks,
Caleb Peterson
4th Year Mechanical Engineering Student
Rochester Institute of Technology

Post by oz » Thu Sep 18, 2008 8:37 am

You might want to take a look at LadyAda's Wave board - and SD boards for hardware. See's also got the library worked out for writing to FAT files, so as far as I can see it should be fairly pain free to do what you want.

Brian Riley at wulfden.org has an eeprom card that will store a bit of data too, maybe with less fuss, on the front end (Freeduino) and more on the back end - getting the data out - you'd have to write a little serial program to send it back to your desktop/laptop.

I've got some SD hardware on the way to develop some prototypes too, and I think it's really exciting to have this capability for the Freeduino user community.

The sensor and lookup table are also pretty simple and implementing them should be a few hours work.

I might be showing my background as an artist but VR sensor? I don't think it's virtual reality. Variable resistance? ABS sensor? antilock brake system?
EMS - all that comes to mind is emergency management system - which seems unlikely. Fill me in if you care to.

Paul

cjp4627 · Post by **cjp4627** » Thu Sep 18, 2008 7:16 pm

I do apolgize for overlooking the abreviations I used. I am so used to talking with the car guys I forget that others may not be used to the terminology.

VR = Variable Reluctance - This will give me some sort of wave signal.
EMS= Engine Management System - Controls the fuel and spark for the engine

I also talked withe the guys that created the EMS and they said I should look at storing the data in a raw binary form and the program can then convert it for me on the computer. If I do it using an SD card this would be quite simple I would think.

Post by oz » Sat Sep 20, 2008 1:23 am

I think you might end wanting more speed and storage than Arduino provides but I might be wrong too. There are a ton of ARM boards out there that run embedded Linux, so the file system is already supported. That might be the way to go on this. I used one for an LED sign, and it was slick solution to storage and memory problem for about $150.

I guess it depends on whether you have a product in mind too or just your immediate project.

Paul

davisjackson · Post by **davisjackson** » Thu Jul 09, 2009 7:45 am

hi guys..

does anyone have a schematic for a frequency to voltage converter and vice-versa?

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Post by oz » Sat Jul 11, 2009 2:15 am

There's a VCO in the LM358 datasheet. Also some in Op Amp Cookbook. These solutions tend to be integrated into chips these days though. Punch in Frequency to Voltage Converter in digikey search engine and see what comes up - Here's the category
http://search.digikey.com/scripts/DkSea ... %20voltage

Paul

min0n · Post by **min0n** » Fri Nov 13, 2009 4:39 pm

hi there,

i use a micro-sd module for datalogging tasks from libelium [1] with fat16lib [2]. it works ok, tested with different atmega. the lib doesnt include delete file option.. it could be nice to implement this feature.

[1] http://www.libelium.com
[2] http://code.google.com/p/fat16lib/

Michaelkfyif · Post by **Michaelkfyif** » Wed Oct 11, 2017 12:35 pm

Had to go for Skramble, great little conversion.

The less said about some of the others the better, although Paperboy was at least a half decent attempt.

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