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Topic: Low Cost RF Transmitter and Receiver Setup x 100 LEDs controlled (Read 647 times) previous topic - next topic

r4gt4g

Looking for a low-cost approach to controlling 100 LEDs via RF.  These LEDs will be battery powered and will need to be blinked on and off and preferably faded, each being controlled separately.  They will be at a short distance from the transmitter yet unable to be wired. 

I am trying to figure out how to minimize costs and yet still be able to control these 100 LEDs. Any suggestions?

johnwasser

So each LED, in addition to a battery, will need an RF receiver and probably a small processor to receive addressing information and determine if this is the LED being addressed.  You can probably use an ATtiny85  ($1.18) processor, the VirtualWire library for sending messages and a cheap OOK RF receiver to get the raw data.  The receivers you can get via Alibaba.com for $0.85 each:
http://www.alibaba.com/product-gs/268050244/RF_receiver_KST_RX300R.html
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r4gt4g

Thanks,  :) :)

Perhaps I should post this in a separate topic (?) but could you comment on my options for transmittor processor / board?  Specifically, I would like to figure out if it's feasible to run multiple, looping routines (multithreaded, sort of) to blink these 100 LEDs in sequences, concurrently.  That is, LED 1, then LED 2, then LED 3, etc.  Meanwhile, LED 8, LED 9, LED 10, etc. (with LED 8 initiated sometime after LED 1 sequence started). 
The reason for this is because these light sequences should start and end independently to get the desired effect and are initiated randomly via user interface. 

johnwasser

You can write your code such that it appears that two sequences are operating independently.
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CrossRoads

Is each LED going to be its own independent piece of hardware with its own battery?
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

r4gt4g

yes, each LED as separate piece of hardware with own battery.

CrossRoads

Might want to look into Lipo battery, charger, and 3.3V 8 MHz Promini with 434 MHz receiver at  each LED node.
Run virtualwire library, all nodes monitor wireless coming in for direction on what to do. Might be direct control (#3, on, time goes by #3, off)
or it might be a sequence with pre-set timing (#5, sequence A) which runs, then goes back to waiting for a command.
In both cases,  a master transmitter sends out the commands.
Use MAX1811 chip for charge control, either 100mA or 500mA, make a central docking station that you can connect them all to for charging.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

r4gt4g

Thanks, this helps a lot.
I like the preset sequence idea.  I will look closely at your battery suggestions.

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