I'm writing a CLI that interacts with an external USB device. The device's status is discovered by reading the Status registers, 24x 8 bits wide. The register values are read from a serial port and arrive as an array of Strings:

=> ["000", "000", "000", "000", "086", "003", "000", "000", "255", "255", ...]

The registers are in 2 formats, bit flags and BCD (I'm not sure of Correct terminology here). They can be mix also.

Bit flags

A value of 34 (0b00100010) means 'Error 16' and 'Error 12' are present.

BCD

A value of 3 (0b00000011) means 'State D'

Is there an elegant Ruby way (or conventions) for storing and looking up this type of String data?

CodePudding user response：

Although I don't quite understand what's the relation between the 24*8 Status registers and Bit flags and BCD, but I think it's just about the number base conversion. You can use to_s if you want to change the number base from 2 to 36.

5.to_s(2)
# => '101'
255.to_s(2)
# => '11111111'
36.to_s(36)
# => '10'

After you convert the number to binary, you can use rjust to supplement with the leading zeros.

5.to_s(2).rjust(8, '0')
# => '00000101'

Then you can use the index of the string to decide what is the status now.

For Bit flags, you can make a array of errors:

errors = ['Error 10', 'Error 11', 'Error 12', 'Error 13', 'Error 14', 'Error 15', 'Error 16', 'Error 17']
'034'.to_i.to_s(2).rjust(8, '0').chars.each_with_index.map do |bit, index|
  bit == '1' ? errors[index] : nil
end.compact
# => ["Error 12", "Error 16"]

For BCD you can make a Hash variable for the states:

states = {
  '000' => 'A',
  '001' => 'B',
  '010' => 'C',
  '011' => 'D',
  '111' => 'E',
}
bits = '003'.to_i.to_s(2).rjust(8, '0')[-3..-1]
states[bits]
# => 'D'

btw, your markdown tables don't display well...