One receiver, 4 transmitters

Hello, I want to set up a relatively simple system: one card receives information from 4 other cards. This information is simply a number. The transmitter unit 1 should simply be able to send the number 1, the transmitter unit 2 the number 2 etc ...

The receiver can therefore receive either a 1 or a 2 etc ...

So at the beginning I thought of installing a master bluetooth card on each sending card, and suddenly 4 receiving bluetooth cards on the main card. : o

Then I turned to the RF433Mhz modules. These modules look good but I have no idea how I can make 4 transmitters communicate with a single receiver. : smiley-confused:

I have also heard of another module, the nRF24L01, but I also do not know how to set up the structure mentioned above. :(

I am ready for any solution! Thank you in advance and have a nice day ! :)

Start with the cheap 433 MHz modules and use VirtualWire to send data. Put a 17 cm piece of straight wire on each module, for an antenna.

There is only one "channel" so any number of transmitters can communicate with any number of receivers. You must make sure that transmissions don't overlap.

No collision avoidance with those. Get NFR24's, use pipes. collision avoidance and you can acknowledge recipts.

You probably need to go with the concept that the receiver is the master and controls receiving the data from the slave boards. The master contacts the slaves in turn requesting data from each slave in turn.

Have a look at this Simple nRF24L01+ Tutorial.

It includes an example for a master and 2 slaves that can easily be extended to a larger number of slaves.

Wireless problems can be very difficult to debug so get the wireless part working on its own before you start adding any other features.

The examples are as simple as I could make them and they have worked for other Forum members. If you get stuck it will be easier to help with code that I am familiar with. Start by getting the first example to work