With the nRF24E1 and nRF24E2, in this document called nRF24Ex, from Nordic
VLSI ASA is it now possible to design a wireless keyboard for the 2.4GHz ISM band.
The nRF24Ex series has an embedded 8051 microcontroller, a 9 channel ADC and the
same RF part as the popular nRF2401/nRF2402. The nRF24Ex series can run at
voltages from 1.9V to 3.6V making it especially suited for battery applications. This
white paper will show how a keyboard scan matrix can be realized by using the
nRF24Ex.