An imaging device such as a CMOS image sensor has a cover attached to a standoff surrounding a micro-lens array. A female housing has a locking arm that locks the to-be-locked part, thus holding both housings undisplaceably relative to each other in a separation direction after the housings fit together properly. A time frame between receipt of two consecutive pulses is measured to determine whether the pulses represent zero bits or one bits. Dynamic status lights and back lights may provide illumination of varying colors and intensities.