-- A/D (Analog to Digital) input services using libsimpleio -- Copyright (C)2017-2023, Philip Munts dba Munts Technologies. -- -- Redistribution and use in source and binary forms, with or without -- modification, are permitted provided that the following conditions are met: -- -- * Redistributions of source code must retain the above copyright notice, -- this list of conditions and the following disclaimer. -- -- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" -- AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE -- IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE -- ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE -- LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR -- CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF -- SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS -- INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN -- CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) -- ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE -- POSSIBILITY OF SUCH DAMAGE. WITH errno; WITH libADC; PACKAGE BODY ADC.libsimpleio IS -- ADC input object constructor FUNCTION Create (desg : Device.Designator; resolution : Positive := Analog.MaxResolution) RETURN Analog.Input IS Self : InputSubclass; BEGIN Self.Initialize(desg, resolution); RETURN NEW InputSubclass'(Self); END Create; -- ADC input object initializer PROCEDURE Initialize (Self : IN OUT InputSubclass; desg : Device.Designator; resolution : Positive := Analog.MaxResolution) IS fd : Integer; error : Integer; BEGIN Self.Destroy; libADC.Open(desg.chip, desg.chan, fd, error); IF error /= 0 THEN RAISE ADC_Error WITH "libADC.Open() failed, " & errno.strerror(error); END IF; Self := InputSubclass'(fd, resolution); END Initialize; -- ADC input object destroyer PROCEDURE Destroy(Self : IN OUT InputSubclass) IS error : Integer; BEGIN IF Self = Destroyed THEN RETURN; END IF; libADC.Close(Self.fd, error); Self := Destroyed; IF error /= 0 THEN RAISE ADC_Error WITH "libADC.Close() failed, " & errno.strerror(error); END IF; END Destroy; -- ADC input read method FUNCTION Get (Self : IN OUT InputSubclass) RETURN Analog.Sample IS sample : Integer; error : Integer; BEGIN Self.CheckDestroyed; libADC.Read(Self.fd, sample, error); IF error /= 0 THEN RAISE ADC_Error WITH "libADC.Read() failed, " & errno.strerror(error); END IF; RETURN Analog.Sample(sample); END Get; -- Retrieve the ADC resolution FUNCTION GetResolution(Self : IN OUT InputSubclass) RETURN Positive IS BEGIN Self.CheckDestroyed; RETURN Self.resolution; END GetResolution; -- Retrieve the underlying Linux file descriptor FUNCTION fd(Self : InputSubclass) RETURN Integer IS BEGIN Self.CheckDestroyed; RETURN Self.fd; END fd; -- Check whether ADC input has been destroyed PROCEDURE CheckDestroyed(Self : InputSubclass) IS BEGIN IF Self = Destroyed THEN RAISE ADC_Error WITH "Analog input has been destroyed"; END IF; END CheckDestroyed; END ADC.libsimpleio;