We need taht small SMD version of the NRF24 radio module and the microcontroller of the Arduino, and that's the ATMega328p- au chip. Then we need 2 H bridge ICs, the MC1508, and the rest are small parts such as capacitors, resistors and diodes. We will need a diode with 0.5V dropvoltage in order to get the 3.3V from the 4.2 battery.
