Bitclock is a clock made of binary integers to help you practice reading binary.
For each digit from left to right compute the sum: For each value place from top to bottom, 8 to 1: If the bit is on then add that value to the sum.
A BitDigit is an array of 4 bits which represents a single digit. Positions in the array signify place values 8, 4, 2, and 1. The value stored in that position may be either a 0 or a 1. If the value is a 1, then the corresponding place value should be added to the sum. If the value is a 0, then the corresponding place value is ignored.
// 8 4 2 1
[1, 0, 0, 1] // 8 + 0 + 0 + 1 = 9
[0, 1, 1, 0] // 0 + 4 + 2 + 0 = 6
A BitTime is an array of BitDigits. Each item is a digit in the current time read left to right.
// 12:34:56
[
// 8 4 2 1
[0, 0, 0, 1], // H1: 0 + 0 + 0 + 1 = 1
[0, 0, 1, 0], // H2: 0 + 0 + 2 + 0 = 2
[0, 0, 1, 1], // M1: 0 + 0 + 2 + 1 = 3
[0, 1, 0, 0], // M2: 0 + 1 + 0 + 0 = 4
[0, 1, 0, 1], // S1: 0 + 1 + 0 + 1 = 5
[0, 1, 1, 0] // S2: 0 + 1 + 1 + 0 = 6
]
Backends retrieve the current time and transform it into a BitTime.
Frontends transform a BitTime into something an end user can interpret. Reference implementations exist to draw pixels in a web page or favicon, but ambitious hackers could write to a visual CLI, LEDs, audio, or even a braille terminal.