% gui.daqinput
% A widget for analog data acquisition
%
% W = gui.daqinput() creates a widget for configuring and retrieving
% analog data. The acquisition can be configured either programmatically
% (by setting relevant properties) or via the GUI. The acquired data
% can be retrieved using the Value property.
%
% W = gui.daqinput(G) creates the widget and adds it to the gui
% container G.
%
% Note:
% 1) This widget requires the Data Acquisition Toolbox.
% 2) The data acquisition is triggered if the user clicks on the "Start"
% button, or if the START method is called.
% 3) This widget does NOT plot the acquired data.
% 4) If the figure window is closed (or the gui.daqinput widget is
% explicitly deleted), any ongoing data acquisition is stopped and
% the acquisition hardware is reset.
%
% Sample usage:
% g = gui.autogui;
% daq = gui.daqinput;
% daq.AdaptorName = 'winsound';
% % ...
% while g.waitForInput()
% info = daq.Value;
% plot(info.time, info.data);
% end
% delete(daq); % stops acquisition and deletes the daq.daqinput object
%
% Also see:
% <a href="matlab:help gui.daqinput.Value">gui.daqinput.Value</a>
% <a href="matlab:help gui.daqinput.start">gui.daqinput.start</a>
% <a href="matlab:help gui.stripchart">gui.stripchart</a>
% Copyright 2009 The MathWorks, Inc.
classdef (Sealed) daqinput < gui.widget
properties (Dependent)
% Value
% A structure containing the most-recently acquired data.
%
% The structure has two fields:
% data - The acquired samples (a matrix of size BufferSize x N),
% where N is the number of channels being sampled.
% time - The acquisition time of each sample (a vector of length
% BufferSize). The time is measured in seconds since the
% start of the acquisition.
%
% The gui.daqinput widget maintains an internal buffer (of length
% BufferSize), and returns this as the Value. The internal buffer
% is periodically updated with newly-acquired samples and the old
% samples are overwritten. When this update occurs, the
% ValueChangedFcn is invoked.
%
% Consider the following code:
% daq = gui.daqinput;
% % ...
% info1 = daq.Value;
% pause(0.2);
% info2 = daq.Value;
% info1.data and info2.data will have the same length but not
% the same numbers, since the internal buffer may have been
% updated *one or more* times between the two calls. It is the
% caller's responsibility to get the Value before data is lost.
%
% Also see:
% <a href="matlab:help gui.daqinput.BufferSize">BufferSize</a> (property)
% <a href="matlab:help gui.daqinput.start">start</a> (method)
% <a href="matlab:help gui.stripchart">gui.stripchart</a>
Value
end
properties (Dependent, GetAccess=public, SetAccess=private)
% Running
% Indicates the state of the data acquisition.
% true => data acquisition engine is running
% false => data acquisition is not configured or
% has not been started.
%
% Also see:
% <a href="matlab:help gui.daqinput.start">start</a> (method)
% <a href="matlab:help gui.daqinput.stop">stop</a> (method)
Running
end
properties
% AdaptorName
% A string with the name of the adaptor to use for analog data
% acquisition (supported adaptors are 'advantech', 'mcc',
% 'nidaq' and 'winsound'). If the user selects the adaptor using
% the GUI, this property is automatically updated.
%
% Sample usage:
% daq = gui.daqinput;
% daq.AdaptorName = 'winsound';
%
% Also see:
% <a href="matlab:help daq/daqhwinfo">daqhwinfo</a>
AdaptorName
% DeviceId
% A string or number identifying the hardware device. If the user
% selects the DeviceId using the GUI, this property is
% automatically updated.
%
% Sample usage:
% daq = gui.daqinput;
% daq.AdaptorName = 'winsound';
% daq.DeviceId = 0;
%
% Also see:
% <a href="matlab:help daq/daqhwinfo">daqhwinfo</a>
DeviceId
% Channels
% A vector of integers, identifying the channels to be sampled
% from the hardware device. If the user selects the Channels
% using the GUI, this property is automatically updated.
%
% Sample usage:
% daq = gui.daqinput;
% daq.AdaptorName = 'winsound';
% daq.DeviceId = 0;
% daq.Channels = [1 2];
Channels
% SampleRate
% The sampling rate to be used (expressed as the number of
% samples per second).
%
% Sample usage:
% daq = gui.daqinput;
% daq.AdaptorName = 'winsound';
% daq.SampleRate = 11025;
SampleRate
% BufferSize
% The number of samples (per channel) that should be returned by
% the Value property.
%
% Example usage:
% daq = gui.daqinput;
% daq.BufferSize = 1024;
%
% Also see:
% <a href="matlab:help gui.daqinput.Value">Value</a> (property)
BufferSize
end
properties (Access=private)
AiObj = []
CurrentData
CurrentDataTime
UiTitle
UiConfigInfo
UiConfigButton
UiActionButton
ConfigInfoWidth
end
methods
function obj = daqinput(varargin)
obj = obj@gui.widget(varargin{:});
color = obj.getParentUiColor();
obj.UiHandle = gui.util.uiflowcontainer('Parent',obj.ParentUiHandle, ...
'units', 'pixels', ...
'BackgroundColor',color, ...
'FlowDirection', 'bottomup', ...
'tag', 'daqinput-uihandle', ...
'Visible', 'off', ...
'DeleteFcn', @(h,e) delete(obj));
obj.UiActionButton = uicontrol('Parent', obj.UiHandle, ...
'style','Pushbutton', ...
'units', 'pixels', ...
'string', 'Start', ...
'Callback', @(h,e) startstopButtonCallback(obj));
obj.UiConfigButton = uicontrol('Parent', obj.UiHandle, ...
'style','Pushbutton', ...
'units', 'pixels', ...
'string', 'Configure', ...
'Callback', @(h,e) configButtonCallback(obj));
obj.UiConfigInfo = uicontrol('Parent', obj.UiHandle, ...
'style','text', ...
'units', 'pixels', ...
'string', {'',''}, ...
'HorizontalAlignment', 'Left', ...
'FontAngle', 'italic');
obj.UiTitle = uicontrol('Parent', obj.UiHandle, ...
'style','text', ...
'units', 'pixels', ...
'string', 'Analog input', ...
'HorizontalAlignment', 'Left');
obj.AdaptorName = '';
obj.DeviceId = '0';
obj.Channels = [1]; %#ok<NBRAK>
obj.SampleRate = 8000;
obj.BufferSize = 1024;
% obj is the most derived class
obj.Initialized = true;
obj.Visible = true;
end
function delete(obj)
if obj.Running
stop(obj);
end
delete(obj.AiObj);
end
end
methods
% todo: add property (ConfigFile) to save & load config info from.
function set.BufferSize(obj, sz)
if ~(isnumeric(sz) && isscalar(sz) && isreal(sz) && sz > 0)
throw(MException('daqinput:InvalidBufferSize', 'BufferSize should be a positive number'));
end
obj.BufferSize = round(sz);
end
function set.AdaptorName(obj,name)
if ~ischar(name)
throw(MException('daqinput:InvalidAdaptorName', 'Adaptor name should be a string'));
end
obj.AdaptorName = name;
clearAnalogInputObject(obj);
updateConfigString(obj);
end
function set.DeviceId(obj,id)
if ~(ischar(id) || (isnumeric(id) && isscalar(id)))
throw(MException('daqinput:InvalidDeviceId', 'DeviceID should be a string or a number'));
end
obj.DeviceId = id;
clearAnalogInputObject(obj);
updateConfigString(obj);
end
function set.Channels(obj,c)
if ~(isnumeric(c) && isvector(c))
throw(MException('daqinput:InvalidChannels', 'Channels should be a list of channel numbers'));
end
obj.Channels = c;
clearAnalogInputObject(obj);
updateConfigString(obj);
end
function set.SampleRate(obj,rate)
if ~(isnumeric(rate) && isscalar(rate) && isreal(rate) && rate > 0 && fix(rate)==rate)
throw(MException('daqinput:InvalidChannels', 'SampleRate should be a positive number'));
end
if ~isempty(obj.AiObj) && isvalid(obj.AiObj)
stop(obj);
obj.SampleRate = setverify(obj.AiObj, 'SampleRate', rate);
else
obj.SampleRate = rate;
end
updateConfigString(obj);
end
function set.Value(obj, val) %#ok<INUSD>
throw(MException('daqinput:InvalidValue', 'Value cannot be modified'));
end
function out = get.Value(obj)
out = struct('time', obj.CurrentDataTime, ...
'data', obj.CurrentData);
end
function out = get.Running(obj)
out = ~isempty(obj.AiObj) && ...
isvalid(obj.AiObj) && ...
isrunning(obj.AiObj);
end
function start(obj)
% start gui.daqinput method
%
% OBJ.start() starts the data acquisition engine for
% gui.daqinput object OBJ (assuming that the acquisition
% hardware is configured correctly). If the engine is already
% running, this method has no effect.
%
% Calling this method is equivalent to clicking on the
% "Start" button on the widget.
%
% Also see:
% <a href="matlab:help gui.daqinput.Running">Running</a> (property)
% The UiActionButton is updated on StartFcn and StopFcn
% callbacks (so that it reflects any unanticipated stops)
if obj.Running,
return;
end
if isempty(obj.AiObj) || ~isvalid(obj.AiObj)
try
initializeAnalogInput(obj);
catch ME
if isa(obj.AiObj, 'analoginput') && isvalid(obj.AiObj)
delete(obj.AiObj);
obj.AiObj = [];
end
errorString = {'Unable to create analog input object', ...
ME.message };
errordlg(errorString, 'Analog input', 'modal');
return;
end
end
start(obj.AiObj); % automatic trigger
end
function stop(obj)
% stop gui.daqinput method
%
% OBJ.stop() stops the data acquisition engine for
% gui.daqinput object OBJ. If the engine is already stopped,
% this method has no effect.
%
% Calling this method is equivalent to clicking on the
% "Stop" button on the widget.
%
% Also see:
% <a href="matlab:help gui.daqinput.Running">Running</a> (property)
if ~obj.Running,
return;
end
stop(obj.AiObj);
end
end
methods(Access=private)
% errors should be caught by caller
function initializeAnalogInput(obj)
assert(isempty(obj.AiObj) || ~isvalid(obj.AiObj));
if isempty(obj.AdaptorName)
throw(MException('daqinput:InvalidConfiguration', ...
'Adaptor name is not configured'));
end
% Use a numeric device Id if possible, as it yields a more
% useful message in case of error
devIdNum = str2double(obj.DeviceId);
if ~isnan(devIdNum)
obj.AiObj = analoginput(obj.AdaptorName, devIdNum);
else
obj.AiObj = analoginput(obj.AdaptorName, obj.DeviceId);
end
set(obj.AiObj, 'tag', 'gui.daqinput');
addchannel(obj.AiObj, obj.Channels);
obj.SampleRate = setverify(obj.AiObj, 'SampleRate', obj.SampleRate);
set(obj.AiObj, 'SamplesPerTrigger', inf);
set(obj.AiObj, 'SamplesAcquiredFcnCount', obj.BufferSize, ...
'SamplesAcquiredFcn', @(h,e) localDaqGetData(obj), ...
'StartFcn', @(h,e) updateAiStatus(obj,true), ...
'StopFcn', @(h,e) updateAiStatus(obj,false), ...
'RuntimeErrorFcn', @(h,e) localDaqErrorFcn(obj,e));
obj.CurrentData = zeros(obj.BufferSize,1);
obj.CurrentDataTime = zeros(obj.BufferSize,1);
end
end
methods(Hidden)
function updateAiStatus(obj, acqStarting)
if acqStarting
set(obj.UiActionButton, 'String', 'Stop');
else
set(obj.UiActionButton, 'String', 'Start');
end
end
% invoked whenever there is a runtime error in the data acquisition
% (the default handler for this is daqcallback.m).
function localDaqErrorFcn(obj, event) %#ok<INUSL>
msg = sprintf('%s event occurred during the data acquisition', event.Type);
errordlg(msg, 'Analog input', 'modal');
end
function localDaqGetData(obj)
n = get(obj.AiObj, 'SamplesAvailable');
if n < obj.BufferSize, return; end
% obj.CurrentData will have multiple columns if # of channels > 1
[obj.CurrentData, obj.CurrentDataTime] = getdata(obj.AiObj, obj.BufferSize);
notify(obj, 'ValueChanged');
end
function startstopButtonCallback(obj)
if ~obj.Running
start(obj);
else
stop(obj);
end
end
function configButtonCallback(obj)
currentConfig = struct('adaptor', obj.AdaptorName, ...
'boardId', obj.DeviceId, ...
'channels', obj.Channels, ...
'sampleRate', obj.SampleRate);
newConfig = guiGetDaqInputParams(currentConfig);
if ~isempty(newConfig)
obj.AdaptorName = newConfig.adaptor;
obj.DeviceId = newConfig.boardId;
obj.Channels = newConfig.channels;
obj.SampleRate = newConfig.sampleRate;
end
end
end
methods(Access=protected)
function initNotify(obj)
[width,totalHeight] = updateSize(obj);
obj.Position = struct('width', width, 'height', totalHeight);
if ~license('test','Data_Acq_Toolbox')
warning('daqinput:MissingDataAcqToolbox', ...
'This demo requires the Data Acquisition Toolbox');
end
end
% called after position is changed
% pos is [x y w h] the new position.
% nan's indicate default (unmodified) values
function postPositionChange(obj, pos) %#ok<INUSD>
if ~isnan(pos(3))
% the -5 is a fudge factor to clean up edges
updateSize(obj, pos(3)-5);
% there is no simple way to get from pixel size of the
% uicontrol to number of characters (the 'characters' units
% does a fixed scaling and ignores fontsize; the 'extent'
% property says how big the uicontrol must be to fit the
% text but not how big the text can be to fit the
% uicontrol). So use a default scaling.
pixelsPerCharWidth = 7;
obj.ConfigInfoWidth = floor(pos(3)/pixelsPerCharWidth);
updateConfigString(obj);
end
end
end
methods(Access=private)
function clearAnalogInputObject(obj)
if ~isempty(obj.AiObj)
if obj.Running
stop(obj);
end
delete(obj.AiObj);
obj.AiObj = [];
end
end
function updateConfigString(obj)
switch numel(obj.Channels)
case 0, channelStr = 'No channels';
case 1, channelStr = ['channel ' num2str(obj.Channels)];
otherwise
channelLst = sprintf('%d,',obj.Channels);
channelStr = ['channels ' channelLst(1:end-1)];
end
if isempty(obj.AdaptorName)
row1 = 'No adaptor';
else
if isnumeric(obj.DeviceId)
deviceIdStr = num2str(obj.DeviceId);
else
deviceIdStr = obj.DeviceId;
end
row1 = sprintf('Adaptor %s (%s)', obj.AdaptorName, deviceIdStr);
end
row2 = sprintf('%s at %d Hz', channelStr, obj.SampleRate);
set(obj.UiConfigInfo, 'string', ...
{trimString(row1,obj.ConfigInfoWidth), ...
trimString(row2,obj.ConfigInfoWidth)});
end
function [width,totalHeight] = updateSize(obj, newwidth)
titleExtent = get(obj.UiTitle,'Extent'); % x y w h
configInfoExtent = get(obj.UiConfigInfo, 'Extent');
configExtent = get(obj.UiConfigButton,'Extent'); % x y w h
if exist('newwidth','var') && newwidth > 0
width = newwidth;
else
width = max([titleExtent(3) configInfoExtent(3) configExtent(3)]) + 10;
end
totalHeight = titleExtent(4) + configInfoExtent(4) + 2*configExtent(4) + 20;
set(obj.UiTitle, 'HeightLimits', titleExtent([4 4]), ...
'WidthLimits', width([1 1]));
set(obj.UiConfigInfo, 'HeightLimits', configInfoExtent([4 4]), ...
'WidthLimits', width([1 1]));
set(obj.UiConfigButton, 'HeightLimits', configExtent([4 4]), ...
'WidthLimits', width([1 1]));
set(obj.UiActionButton, 'HeightLimits', configExtent([4 4]), ...
'WidthLimits', width([1 1]));
end
end
end
function out = trimString(s, maxlen)
if numel(s) > maxlen
if maxlen < 3
out = s(1:maxlen);
else
out = [s(1:maxlen-2) '..'];
end
else
out = s;
end
end
