I am making a wireless setup for a game show that has one 'brain' unit and six buzzer units, all using Arduino Unos. The buzzer units are where the contestant 'buzzes in' to answer a question.
The reason for this post is to try to ascertain the best wireless module to use that can have one 'master' and six or more 'slaves'. The 'slaves' need to be uniquely addressable by the 'master' and communication must be bidirectional. Range only need be about 150' or so.
I currently am using 433 MHz transmit and receive modules with HT12E and HT12D encoder and decoder, have had some success but the encoder/decoder chips seem to be inconsistent and have drop outs. I am also trying HC-05 BT modules as well.
I'm hoping the experts on the subject can point me in the right direction. Thanks fr reading.
The Very FIRST step in your project is to test the communications to ensure it is reliable. Otherwise there is no need to go any further with the project.
Understand that only one slave can transmit at a time and that is usually when the master asks each slave in turn if it has data to send. That is called "polling". If more than one slave tries to transmit, the master will receive garbage. Communication can be bidirectional, but can never be simultaneous.
Your topic has been moved to a more suitable location on the forum. Installation and Troubleshooting is not for advice on (nor for problems with) your project.
This already sounds unfair. Or randomly advantageous to a player.
How long will it take to see and react to a contestant ringing in?
If two satellites ring in simultaneously, what in the worst case will be the time between that instant and the recognition of any A ring-in, and then the time until the other B ring in is seen?
433 radio sets should be entirely adequate if you do it the way you propose. This
HT12E and HT12D encoder and decoder
is overkill, an Arduino can use the '433 OOK signal directly, there are libraries that will take care of quite a bit of the pain.
Less pain in any event than other radio sets.
150 feet is possible, but you will want to have good antennae and use a proper circuit, layout and lead dress.
What is your programming level?
What is the concept for the base station, and for the buzzer, as far as additional lamps or switches or sound effects or score display or whatever?
Thanks for the idea of ditching the encoder and decoder, had considered that and will try it.
I'm not a newbie to electronics and devices, been at it working in R&D for over 30 years doing design and fabrication of test fixtures, prototypes, motion control etc. Wireless arena IS new to me so I'm on the learning curve. My programming level is a few thousand hours of VB6, a few hundred hours of Visual C++.
You are correct about the buzzer boxes needing individual IDs, that is settable by a dip switch in each buzzer box, read by code. The 'first buzzed in' being latched with all other buzzers locked is handled in software. The odds of a tie are quite slim. I designed and built a Pinewood Derby finish line for my son's Cub Scout pack and faced the same issue of a tie many years ago lol.
So... the plan is for the base station to listen to all the buzzer boxes, first to get through wins?
I hope you are right, that is that the...
...odds of a tie are quite slim.
I thought you might have meant the base station would be polling the buzzer boxes. In my imagination (!) just listening will be full of conflict, not ties but conflicting rf packets. I guess you will see.
Obvsly this will be more true the tinier the messages.
I once did a medium deep dive on the Jeopardy signaling system. One thing I hadn't known or had forgotten is that contestants are locked out for a punishment period if they try ring in before Alex has finished with the question (lamp comes on?), and in some other cases.
It's good reading no matter what you google up on the subject. If you are aiming for a Jeopardy type ring-in system. I think the "real" one is hardwired and mostly hardware based, don't know if they went so far as to make sure the cables to each contestant were of equal length.
It will be 'interrupt based' rather than polling. First buzz in is detected, others locked out for n seconds or upon receipt of a 'led done signal' from buzzer.
