Wireless Tachometer - Design Help

[DanPBP]

Hello Guys,

I need some design ideas for a wireless tachometer... I can handle the source code, but I'm a little rusty on technology these days... :p

I have a few brushless R/C trucks that have an encoder (phototransistor/LED) on the transmission and I would like to measure the RPM remotely... This is the general idea...

http://img18.imageshack.us/img18/1246/wirelesstach.jpg

I need to read up to 50.000 RPM and refresh that number in "real time" on a display (I prefer LED display and/or LED bargraph)...

My main concern is which PIC and wireless TX/RX to use that can handle the refresh rate... I mean, this is not like having the PIC and the display connected directly to the sensor, there's some delay on the wirelles link, right?

So, any ideas on which PIC and wireless TX/RX to use will be much appreciated! Feel free to comment anything you want... :rolleyes:

Daniel.

PS: I like this for the display: http://cgi.ebay.com/1-5-Character-Height-7-segment-LED-Information-Board_W0QQitemZ350174609382QQcmdZViewItemQQptZLH_D efaultDomain_0?hash=item350174609382&_trksid=p4634.c0.m14.l1262#ebayphotohosting

[Acetronics2]

Hi, Daniel,

I Think Xbee Pro transmission could make both the R/C "classical" function AND the Data real time logging to the Pilot.

Some Big brands already have done it ... if I'm right.

I also saw some "amateur" designs on the Web ...

Alain

[DanPBP]

Well, I bought this transceiver:

http://cm.ebay.com/cm/ck/1065-29392-2357-0?uid=445238009&site=0&ver=EOIBSA080805&lk=ItemDescriptionANDimage&Item=250410884492

And this LED bargraph and display:

http://cm.ebay.com/cm/ck/1065-29392-2357-0?uid=445238009&site=0&ver=EOIBSA080805&lk=ItemDescriptionANDimage&Item=230339128924

http://cm.ebay.com/cm/ck/1065-29392-2357-0?uid=445238009&site=0&ver=EOIBSA080805&lk=ItemDescriptionANDimage&Item=250329856385

As soon as they arrive, I'll start testing this project...