Dispatching the keyboard and sensor cable, we pop the main board—and attached inductive charging coil—from the keyboard.

And the brains of this (small) beast: Nordic Semiconductor nRF51822 2.4 GHz Bluetooth and 32 bit ARM Cortex-M0 microcontroller

Semtech TS51221 wireless power receiver voltage regulator

STMicroelectronics BAL-NRF01D3 50 Ω Bluetooth balun

Dialog Semiconductor (formerly Silego) SLG46110 Programmable mixed signal array (likely)

Texas Instruments LP5907SNX-3.3 250 mA / 3.3 V LDO regulator