This project is intended to be an anti-paparazzi device. The idea is to detect if a camera system or other optical system is directed towards the device. The detection is done by scanning the surroundings with a laser beam, and detect any reflections. All optical systems will have a retro-reflex, directing the reflected beam in the opposing direction of the incoming beam, e.g. back to the device.
Natural speed of the combination of motor and drive wheel results in a scanning speed of 16 Hz. Multiplied by 360 (for 1 degree of angular resolution) means that the clock should be around 5.8 kHz.
Choosing oscillator components according to HFE4046B datasheet section 11.1 (VCO without frequency offset)with a 5760 Hz f0 gives; R1 = 100 kOhm or R1 = 10 kOhm C1 = 800 pF C1 = 7000 pF
With assumed limits of 12 to 20 Hz the clock limits become 4320 resp. 7200 Hz. (fmax/fmin = 1.667) Choosing components (VFO with frequency offset) leads to values: R1 = 80 kOhm R2 = 100 kOhm C1 = 2000 pF
Components at hand: R1 = 10 kOhm C1 = 10 nF