digiOutBela

Writes a Bela digital output pin.

This opcode requires the Bela Csound host. See Bela digital input and output for setup, pin numbering and shared-pin rules.

Syntax

ModernClassic

digiOutBela(kstate, ipin)
digiOutBela(astate, ipin)

digiOutBela kstate, ipin
digiOutBela astate, ipin

Initialization

ipin selects a digital channel from 0 to 15. It is required and fixed at initialization. Fractional values are truncated, then limited to this range. The opcode sets the pin to output on its first performance call.

Performance

kstate or astate sets the output level. Positive values drive the pin high. Zero and negative values drive it low. Use 0 and 1 for clear low and high states. The opcode has no output arguments.

The k-rate form writes at the current digital frame and holds the value for following frames until another write changes it. The a-rate form writes each digital sample separately. These are digital states, regardless of the argument's rate or amplitude.

For a changing pin number or direction, use digiIOBela. Ending a note does not make this opcode reset the pin, so send the desired final state before it ends.

Examples

The example generates a one-Hz pulse on digital output 1, with equal high and low times. Observe it with suitable logic-level test equipment or a correctly wired LED circuit. The final second holds the output low before the instrument ends.

It uses digiOutBela.csd, which must run on the Bela host.

<CsoundSynthesizer>
<CsOptions>
-d
</CsOptions>
<CsInstruments>
// The Bela host supplies ksmps. Match sr to the board's audio rate.
sr = 44100
nchnls = 2
0dbfs = 1

instr SendPulse
  kPhase = phasor(1)
  kState = (kPhase < 0.5 ? 1 : 0)
  kTime = timeinsts()
  if kTime >= p3 - 1 then
    kState = 0
  endif
  digiOutBela(kState, 1)
endin
</CsInstruments>
<CsScore>
i "SendPulse" 0 10
e
</CsScore>
</CsoundSynthesizer>

See also

digiInBela, digiIOBela, Bela digital input and output

Credits

Author Victor Lazzarini, 2017.