I'm hoping this has not already been covered before. I've been replicating a project of a Wireless Laser-Gate Timing System for Track and Field
The project involved 2 x Arduinos and 2 x NRF24L01+ (Finish and Start Modules), plus various other components in those modules. I originally had issues with connecting the modules for the first time and poor range which had been resolved by using a 10uf capacitors on each NRF24 and aluminium foil.
The issue i'm having now is with the Start module that has the speaker. The programme will run for the first time. A '3...2.....Bleep' sound is made which starts the timer. (Which is correct)
After resetting the timer on the finish model the two NR24's won't reconnect. You will get the odd random time when it does connect. However, I noticed when the speaker is either disconnected (which means no '3...2....Bleep' sound to start the timer) the NR24's will reconnect after resetting the timer. Or if the battery in the Start Module is low which meant the sound would not come out properly, the NR24's will reconnect properly.
The only way I can get the NRF24L01+ to reconnect again is if I turn off and on the Start Module.
So it makes me think that the speaker is interfering with the reconnection of the NRF24 modules. I'm using a 9V battery, BD139 transistor and a 3W 4Ohm speaker (which is the same as the person who done this project). Connected to a custom PCB that connects to the arduino.
Below are some pictures of the speaker modules and schematic. If I'm right in thinking that speaker is interfering with the reconnection of the NRF24 modules, does anyone have any ideas to resolve this issue. Thanks.