Merge pull request #125 from Remi-Gau/remi-wait_for_trigger

make waitFortrigger return the time stamp of the last trigger

Author: Remi-Gau

demos/CPP_waitForTriggerDemo.m

@@ -3,18 +3,17 @@
 % add parent/src directory to the path (to make sure we can access the CPP_PTB functions)
 addpath(genpath(fullfile(pwd, '..', 'src')));
 
-cfg.mri.triggerNb = 5;
+cfg.testingDevice = 'mri';
 
+cfg.mri.triggerNb = 5;
 cfg.mri.triggerKey = 't';
 
 KbName('UnifyKeyNames');
 
-%%
-% waitForTrigger(cfg);
-
-%%
 quietMode = false;
-% waitForTrigger(cfg, [], quietMode);
 
-%%
-waitForTrigger(cfg, [], quietMode, cfg.mri.triggerNb);
+fprintf(1, 'Press the letter %s %i times, please.\n', cfg.mri.triggerKey, cfg.mri.triggerNb);
+
+lastTriggerTimeStamp = waitForTrigger(cfg, [], quietMode, cfg.mri.triggerNb);
+
+fprintf(1, 'Thank you. The time stamp of the last trigger was %f.\n', lastTriggerTimeStamp);

src/waitForTrigger.m

@@ -1,6 +1,6 @@
 % (C) Copyright 2020 CPP_PTB developers
 
-function waitForTrigger(varargin)
+function lastTriggerTimeStamp = waitForTrigger(varargin)
     % waitForTrigger(cfg, deviceNumber, quietMode, nbTriggersToWait)
     %
     % Counts a certain number of triggers coming from the scanner before returning.
@@ -45,7 +45,7 @@ function waitForTrigger(varargin)
 
             keyCode = []; %#ok<NASGU>
 
-            [~, ~, keyCode] = KbCheck(deviceNumber);
+            [~, lastTriggerTimeStamp, keyCode] = KbCheck(deviceNumber);
 
             if strcmp(KbName(keyCode), cfg.mri.triggerKey)