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[on:]

I am using the chipKIT Uno32 board (I know it isn't an official Adruino but its all I could get) to make an scrolling LED marque. So far everything is working just fine and I am using 24 pins for a total of 270 individually controllable LEDs. This is wired up to a 3 stage switch that dictates what animation is scrolled.

My main goal is to have a 3 or 4 stage switch which will wirelessly transmit the switch state to the main LED board. The board would then display an animation based on what position the switch was in. The switch will always be in close proximity of the board (no more than 3 meters away at max).

The question is then, what kind of shield could I use for the receiver that I could plug into the chipKIT board and what could I use as the transmitter? It cannot be too simple of a signal since the switch will be paired with the board with many of these "pairs" being very close to each other (meaning one switch can only really control one board to keep signals from crossing over). This doesn't have to be secure really, just a basic "Transmitter 1 transmitting to receiver 1" in the open is fine.

Another thing about the receiver, it would be cool (but not totally required) if it could talk to a smart phone as well. Just being able to send "switch state #" and "scroll message $string" from a phone would be all that I would need.

Any help finding the correct shield and design idea would be much appreciated. Thanks!

[Reply #1 on:]

The question is then, what kind of shield could I use for the receiver

That depends on what receiver you are planning to use.

that I could plug into the chipKIT board

You'll have to figure that out on your own. And, no you can't ask here. This isn't a chipkit forum.

and what could I use as the transmitter?

It's generally best to get one that works with the receiver.

It cannot be too simple of a signal

Why not? How many positions is this switch going to have? How often is it going to change?

with many of these "pairs" being very close to each other (meaning one switch can only really control one board to keep signals from crossing over).

That's going to rule out most of the cheap transmitters and receivers. XBees are still in the running.

Another thing about the receiver, it would be cool (but not totally required) if it could talk to a smart phone as well.

If this is a requirement, you've just eliminated every possible device.

[Reply #2 on:]

During the original kickstarter campaign, I ordered some radio mesh boards from http://www.coloradomicrodevices.com/the-radio-block/.  He is starting to ship the boards out, and I see some people have already gotten their boards.  After all of the kickstarter orders are done, you will be able to order the boards directly.  Now, you probably would not be able to use that with your phone, but I could imagine having a PC that does all of the mesh stuff and then allows the phone to connect via bluetooth or wifi.

Bluetooth is another option, though I suspect trying to pair with and manage all of the devices may be a problem.

[Reply #3 on:]

I use one of these:

http://imall.iteadstudio.com/development-platform/arduino/shields/im120417010.html

on an arduino that is hooked up to the internet via an ethernet shield to transmit instructions received over the internet from my smart phone to another arduino with one of these:

http://imall.iteadstudio.com/development-platform/arduino/shields/im120417006.html

It allows me to control a relay board with 8 relays on it from anywhere in the world (as long as I have cell phone coverage). 

[Reply #4 on:]

@PaulS
Don't worry, I am not asking for chipKIT specific things. I am looking for general advice on how to do wireless communication with these boards, a topic I have no knowledge or experience in.

The final product that I am working on is a turn signal LED board that I can sew into a backpack so while I am riding my bike I can signal turns and have a more fun visibility light. The "everything over simple radio" problem would be that my friend also wants one and if we are riding close to eachother, the signals would get confused. Thus, there has to be some sort of pairing. If I can actually do that over radio waves, then super! I just don't know what is possible with what tech.

@MichaelMeissner
That looks a lot like what I would want. Only a couple of pins and the ability to communicate with other of the same type. Sadly, I would like to get this working soon and can't wait for a undetermined amount of time for them to start selling to everyone.

@jerseyguy1996
These look cool but they seam to take quite a few pins. Is there nothing simpler that could be used? Every pin that I lose to a shield limits my LED board size even more. Also, how easy is it to pair bluetooth devices like these?

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So I guess I can narrow my main question down a bit. What is the simplest method (bluetooth, radio, wifi, ...) to wirelessly pair a receiver and transmitter? What method would take the fewest pins on an Arduino (and a specific shield if one is known)? Is there a transmitter that could be paired using any of the methods and that could give out basic signals (anything that could be computed as int 1-4) without having an Arduino controlling it?

For the last question there, one thought was to use standard short length radio waves from the transmitter and have the receiver only pick up signals on a specific frequency. The transmitter would not need its own micro controller and the frequency could be adjusted with a screw or something similar, powered by a small battery. I do not know if this is even possible, just a thought.

[Reply #5 on:]

I misread your original post, and thought you wanted to have many slaves reporting to a single host, which is why I thought mesh might be better than bluetooth.  For just connecting one to one, I would think bluetooth would be ideal.  You can get bluetooth devices that mimic a serial port (i.e. you hook it up to pins 0/1 and use Serial.println on them).  I believe for pairing you would need to look up the AT commands for pairing.

For example, doing a quick ebay search for 'Arduino bluetooth', I see units like: http://www.ebay.com/itm/Interface-Base-Board-Serial-Transceiver-Bluetooth-Module-For-Arduino-MEGA-UNO-R3-/310531685523?pt=LH_DefaultDomain_0&hash=item484d217c93.  Note, I just noticed TX/RX are 3.3 volts, so you would need a voltage converter as well to hook it up to Arduino (compatible) pins.

If your phone has bluetooth, you would be able to pair to it as well.  You can get various apps that will connect over bluetooth.  For example on my Samsung android phone, I have the free app Connection Terminal installed that lets me send/receive simple text messages.

[Reply #6 on:]

I use el-cheapo Hope RFM83 / 85  radio links for non-critical projects, using VirtualWire to send the data.

I get over 50 meters range, even if I scrunch up the antenna wire ( the end of our road is 50 meters away ! )

The first byte I send is an address that only the right decoder/ switch/whatever responds to.

If you only need to switch the data, rather than send it realtime, it should be easy with Arduino ( dont know about chipKIT   :-)

[Reply #7 on:]

The bluetooth shields that I linked to only require two pins, TX and RX.  You write and read to it using Serial.print and Serial.read.  Pairing and communication between bluetooth devices is handled by the shield.

[Reply #8 on:]

The bluetooth shields that I linked to only require two pins, TX and RX.

Thats a more sophisticated way of doing it, but what I suggest needs just one pin each end , and doesn't need a shield.

I am paying less than $3  for a pair of  wireless modules.

[Reply #9 on:]

I use el-cheapo Hope RFM83 / 85  radio links for non-critical projects, using VirtualWire to send the data.

I'm interested in trying these but I notice in Nick Gammon's article about a radio-controlled car based on these that the receiver's data pin couldn't drive the Arduino input pin directly and had to be connected via an op-amp. Do you have the same problem?

[Reply #10 on:]

I use el-cheapo Hope RFM83 / 85  radio links

These look quite good. Doing a basic "sending to # receiver" is good enough for my project at the moment. The problem with the bluetooth shields is that they don't seam compatible with my chipKIT board without doing my own wiring and they are more expensive.

@Boffin1 - Where can you purchase these? I can't seam to find anything through google other than the specs for them.

[Reply #11 on:]

Sorry about the delay, I lost all my notify tags somehow and just found this thread again.

@Boffin1 - Where can you purchase these? I can't seam to find anything through google other than the specs for them.

You should look for agents for Hope,  in South Africa I get them from Nuvision electrical.

I'm interested in trying these but I notice in Nick Gammon's article about a radio-controlled car based on these that the receiver's data pin couldn't drive the Arduino input pin directly and had to be connected via an op-amp. Do you have the same problem?

He was using the RXB1 which is ot from Hope by the look of it.

I have no problems with the RFM83 / 85 receiver and get a full 5v swing into the Arduino pin, even though it is also connected to another decoder as well ( an HT12D ) .

 I am using VirtualWire as opposed to NewSoftSerial as well but it wouldnt make any difference I think.

[Reply #12 on:]

One thing not mentioned, possibly because not very cheapo, is the use of XBee
shields for Arduino. There are several available from different companies. The
big advantage here is that there are many different RF modules that plug into
the same sockets, so you can easily try out different possibilities. Here are
some of the modules that plug in, XBee, BT, wifi, 433 Mhz, etc.

http://www.seeedstudio.com/depot/index.php?main_page=advanced_search_result&search_in_description=1&keyword=beefamily

XBee shields should be compatible with the Chipkit Uc32, as it has regular Arduino
headers. Also, most XBee style modules run at 3.3V. Also, I believe the uC32 also
runs at 3.3V, although the PIC32 pins are 5V tolerant, so you should be able to plug
any shields into it. But best to double-check.

One problem with going really el-cheapo RF is you also get el-cheapo RF comms
reliability. OTOH, the HopeRF modules like the RFM12/22 are pretty well designed,
although I know nothing about the 85s.