nRF8001, nRF51422 or nRF51822


It's my first post here so let introduce myself : I'm a 25 y.o. French electronics engineer and hobbyist. I also like skating (inline skates and ice skates) mainly slalom, jumps, speed run, street ride... And I have any hobby projects related to this sport I want to give life!

I'm here because I want to upgrade one of my actual project with Bluetooth Low Energy. I have 20 little slalom cones with RGB LEDs, power management unit and battery, sensor... And now the game is to build 20 new units with Bluetooth.

First I wanted to add only Bluetooth to control each device individually from an Android smartphone. So nRF8001 was my first choice.

Then I thought to add a feature : configure a mesh network to give each device the ability to share small amount of data with each others. But I read somewhere that nRF8001 can't act as a master, so the devices can't be used without a BLE master (smartphone).

My question is this one :

Now I hesitate between nRF51422 and nRF51822. The good point is that they're pin-to-pin compatible. If I'm right nRF51422 is able to communicate like an nRF24L01 + Bluetooth. I never used 24L01 so I don't know which protocol is better/easier to implement for a small mesh network (up to 20 or 30 devices)? What are the limitations in term of device number and application?

Furthermore, there was a microcontroller on the previous project (PIC24F) with USB bootloader, 3 PWM, 1 ADC, 2 SPI, and 5 inputs with interrupt (push buttons and charger present detection). Actually I don't know if it's better to implement a serial communication between nRF and microcontroller, or if I go only with nRF and do a new code.