Because is good that all modules to be wireless, like speedometer, cadence...etc. I was start testing my prototype to see how all that should be work and implemented. I was need to make new module for that, who will send with NRF24L01 to Dashboard module. In Dashboard module i put new settings screen where you can set your wheel size in inches. And Dashboard module receive signals when wheel is full rotated and then is calculate speed.

In next video you will see all that how works.