Improvements to setOutPut()

[sheffieldnikki]

There is a bug where only mode == 0 can set the output mode. mode == 1 is trapped by the first if clause and never written. And a bitwise operations bug because config_status & 0xef can only set OUTS1:0 to 10 (digital PWM) if the register was already 10 or 11, not if it was 00 or 01.

Suggested improvements:

1. Added function documentation for consistency with rest of library
2. Bug fix: mode == 1 for analog output now works, removed nested if clause
3. Removed duplicate readOneByte() call, function now twice as fast
4. New feature: mode == 2 sets reduced range analog 10-90% (better for some ADCs)
5. Comments inside function to explain clearing/setting register bits
6. Shorthand assignment operator &=
7. Renamed function to setOutput, since "output" is one word
8. removed lowByte(), since by definition config_status is a single byte
9. Folded variable declaration into fewer lines
10. Bug fix: correct bitwise operations for set/clear bits in register

/*******************************************************
  Method: setOutput
  In: 0 for digital PWM
      1 for analog (full range 0-100% of GND to VDD)
      2 for analog (reduced range 10-90%)
  Out: none
  Description: sets output mode in CONF register.
*******************************************************/
void AMS_5600::setOutput(uint8_t mode)
{
  int _conf_lo = _addr_conf+1; // lower byte address
  uint8_t config_status = readOneByte(_conf_lo);
  config_status &= 0b11001111; // bits 5:4 = 00, default
  if (mode == 0) {
    config_status |= 0b100000; // bits 5:4 = 10
  } else if (mode == 2) {
    config_status |= 0b010000; // bits 5:4 = 01
  }
  writeOneByte(_conf_lo, config_status);
}

[Pillar1989]

@sheffieldnick welcome to PR.

[sheffieldnikki]

@Pillar1989 no PR, but you've got my code so you're welcome to merge it if you want.