I need to build a very small arduino based transmitter that will send accelerometer values to another arduino that will be less than 5ft away.
I was hoping to use a pro mini but all of the xbee shields are for the larger arduinos and the package gets very bulky.
Any recommendations?? Doesn't need to be xbee but I heard that its an easy way to acheieve wireless data transmission.
I will have two seperate wireless accelerometer setups sending the data to a single arduino and the receiving arduino (w/ wireless can be larger) its the sending packages that should be as small as possible.
I am planning to control 5 light sources with on transmitter and 5 receivers.
I know that I have some how to encode and decode the signal so the correct light is working. My project is not only about lights, but it is a beginning.
Sure, anyone can receive.
Use VirtualWire library, send the receiver address as part of your message, each receiver sees the message and decides if its for them.
Can send a single byte: upper 3 bits are the address 000-111, next 3 bits are what the receiver is to control (1 of 8 devices), last two bits are on/off status.
VirtualWire adds some bytes to make sure receiver is in sync, and to manchester encode the message for integrity.
transmit side (there is some basic stuff to put in void setup too):
msg[0]=data_to_send; // load the array with the byte of data to send,
vw_send((uint8_t *)msg, strlen(msg)); // send the character out
vw_wait_tx(); // Wait until the whole message is gone
receive side:
// look for wireless input or for unsolicited message from transmitter
uint8_t buf[VW_MAX_MESSAGE_LEN]; // creates buf[0]
uint8_t buflen = VW_MAX_MESSAGE_LEN;
if (vw_get_message(buf, &buflen)) // Non-blocking
{
// break up the byte, see if for this receiver
receiver = buf[0] & B11100000;
if (receiver == Bxxx00000){ // see if upper 3 bits match our address, fill in xxx with 000 to 111
// its us, clear receiver for next time
receiver = B11100000; // B11100000 reserved for no one selected??
//now see which device to handle
device = (buf[0] & B00011100) >> 2; mask off the address & 'command', shift it right 2 bits
// and find the command to perform
command = (buf[0] & B00000011; // mask off the address & device
switch (device){
case 0:
// do command 0, 1,2,3
break;
case 1:
// do command 0, 1,2,3
break;
:
:
case 7:
// do command 0,1,2,3
break;
} // end switch case
} end if receiver
} end if get message
You'll have read & understand the VirtualWire library, this will make a lot more sense then. It is very straightforward to use.
MartinAM:
Sorry to asking in your post, but is it possible to use one TX and 6 RXs?
Yep. I have one LED installation where there are 20 nodes that have an nRF24L01+ module in them (these guys). One of them is designated the master node, and the rest are all slaves. The master sends out packets with an address on them, and the nodes all figure out if it's for them.
Three if you count Nordic's datasheet, which has an extensive example of how to set up one master and 6 slaves in a "multiceiver" setup using 6 parallel data pipes. (I didn't do it that way.)
Hi! Just wanted to find out, fxmech, what combo did you use for your project, if you can recall. I'm looking for info on this very same features and I thought It was better to see what's already been discussed. Thanks!
There have been some new offerings in the three years since this thread was last active. You might want to look at the 'Moteino' --> http://lowpowerlab.com/moteino/
