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[Reply #30 on:]

Oh you'll probably hear from me in the near future with a project goal ;-)

[Reply #31 on:]

So I should start thinking about a shield with connector for a remote display & RF?

[Reply #32 on:]

So I should start thinking about a shield with connector for a remote display & RF?

LOL, I have been thinking about it. I'll send you some notes. What I might do first is a wifi based web server with its own mpu on a shield that can talk to the main board. It occured to me that maybe a jumper would have been in order to let users flash an update to an atmel MPU that's on a shield vs the one on the main board :-(

[Reply #33 on:]

This is the first time you've mentioned having a 2nd processor. Can't think of everything all the time.

[Reply #34 on:]

This is the first time you've mentioned having a 2nd processor. Can't think of everything all the time.

Oh of course its not your fault. It didn't occur to me until just recently.

[Reply #35 on:]

have you seen the jeenode?
http://jeelabs.net/projects/hardware/wiki/JeeNode
It communicates thru RF.
Not sure if it will be usefull for you.

Best regards Alban

[Reply #36 on:]

@skyjumper,
I was just saying its hard to think of everything one could possibly do with a card for all future scenarios, not that we forgot to include something.  I see folks are talking of a math coprocessor now too, that's certainly a big change in capability I wouldn't have imagined for an 8-bit processor.

@Alban,
We've taken the jeenode and gone way beyond that. ATMega1284 (lots more memory, more IO, 2nd serial ports), added SPI UART for more IO, added RS232 & RS485 drives (converts signal levels), added Real Time Clock with battery backup (bottom of the board), added Secure Data (SD) card. Adding RF will be straight forward, just need to pick from the myriad of transmitters, receivers, or transceivers available.  Really crammed a lot of stuff into 60x80mm and 80x100mm footprints.  See the cards here www.crossroadsfencing.com/BobuinoRev17

[Reply #37 on:]

which battery do you suggest for using?

Arduino nano works with 5v (may be 3v?)
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=220820957973&ssPageName=STRK:MEWNX:IT

and th nRF24 works with 1.9V-3.3V Vcc input
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280718046569&ssPageName=STRK:MEWNX:IT

I prefer a small rechargeable battery.
can't find the right battery for me.

Thanks again

[Reply #38 on:]

I would go with three AA type batteries to the nano VCC/5V pin and get 50mA of 3.3V from the FTDI chip.
Or, pick off 3V from two of the batteries for the transceiver if 50mA is not enough current.

[Reply #39 on:]

what do you say about 1/2 AA?
there is a 1.2V each, or 3V each

[Reply #40 on:]

4 x 1.2  = 4.8V, good for nano
2 x 1.2 = 2.4, good for RF

[Reply #41 on:]

Thank you for your answers,
but I want it to be small...do you this 3 X 1.3 = 3.6V is enough for the nano+rf ?

[Reply #42 on:]

3 x 1.3 = 3.9

Add a diode between 3.9 & the RF, bring it down to 3.2, should be okay then.

[Reply #43 on:]

haha,  1.2X3=3.6

I guess its the same, so thanks!