comparison projects/stepper/render.cpp @ 268:8d80eda512cd prerelease

Added new overlay for using PRU0 or PRU1, a script to halt board on button press, and several example projects

+/*
+ * render.cpp
+ *
+ *  Created on: Oct 24, 2014
+ *      Author: parallels
+ */
+
+
+#include <BeagleRT.h>
+#include <Utilities.h>
+
+const int kStepLengthSlow = 1000;
+const int kStepLengthFast = 500;
+
+int gStepLengthSamples = kStepLengthSlow;
+
+const int gPinA1 = P8_27;
+const int gPinA2 = P8_28;
+const int gPinB1 = P8_29;
+const int gPinB2 = P8_30;
+const int gPinServo = P9_16;
+
+int gStepCounter = 0;
+int gPhase = 0;
+
+int gServoCounter = 0;
+
+
+enum {
+	kStateMoveRight1 = 0,
+	kStateMoveLeft1,
+	kStateMoveRight2,
+	kStateMoveLeft2,
+	kStateMoveRight3,
+	kStateMoveLeft3,
+	kStateSpin,
+	kStateMax
+};
+
+int gState = 0;
+int gStateCounter = 0;
+
+// setup() is called once before the audio rendering starts.
+// Use it to perform any initialisation and allocation which is dependent
+// on the period size or sample rate.
+//
+// userData holds an opaque pointer to a data structure that was passed
+// in from the call to initAudio().
+//
+// Return true on success; returning false halts the program.
+
+bool setup(BeagleRTContext *context, void *userData)
+{	
+	// This project makes the assumption that the audio and digital
+	// sample rates are the same. But check it to be sure!
+	if(context->audioFrames != context->digitalFrames) {
+		rt_printf("Error: this project needs the audio and digital sample rates to be the same.\n");
+		return false;
+	}
+	
+	pinModeFrame(context, 0, gPinA1, OUTPUT);
+	pinModeFrame(context, 0, gPinA2, OUTPUT);
+	pinModeFrame(context, 0, gPinB1, OUTPUT);
+	pinModeFrame(context, 0, gPinB2, OUTPUT);
+	pinModeFrame(context, 0, gPinServo, OUTPUT);
+		
+	return true;
+}
+
+// render() is called regularly at the highest priority by the audio engine.
+// Input and output are given from the audio hardware and the other
+// ADCs and DACs (if available). If only audio is available, numMatrixFrames
+// will be 0.
+
+void render(BeagleRTContext *context, void *userData)
+{
+	for(unsigned int n = 0; n < context->audioFrames; n++) {
+		if(gPhase == 0 || gPhase == 1) {
+			digitalWriteFrameOnce(context, n, gPinB1, HIGH);
+			digitalWriteFrameOnce(context, n, gPinB2, LOW);
+		}
+		else {
+			digitalWriteFrameOnce(context, n, gPinB1, LOW);
+			digitalWriteFrameOnce(context, n, gPinB2, HIGH);			
+		}
+		
+		if(gPhase == 1 || gPhase == 2) {
+			digitalWriteFrameOnce(context, n, gPinA1, HIGH);
+			digitalWriteFrameOnce(context, n, gPinA2, LOW);
+		}
+		else {
+			digitalWriteFrameOnce(context, n, gPinA1, LOW);
+			digitalWriteFrameOnce(context, n, gPinA2, HIGH);			
+		}
+		
+		if(--gServoCounter > 0) 
+			digitalWriteFrameOnce(context, n, gPinServo, HIGH);
+		else
+			digitalWriteFrameOnce(context, n, gPinServo, LOW);
+		
+		if(++gStepCounter >= gStepLengthSamples) {
+			gStateCounter++;
+			
+			switch(gState) {
+				case kStateMoveRight1:
+				case kStateMoveRight2:
+				case kStateMoveRight3:
+					gPhase = (gPhase + 1) & 3;
+					break;
+				case kStateMoveLeft1:
+				case kStateMoveLeft2:
+				case kStateMoveLeft3:				
+					gPhase = (gPhase + 3) & 3;	
+					break;
+				case kStateSpin:
+					gPhase = (gPhase + 1) & 3;
+					break;		
+			}
+			
+			if(gState == kStateSpin) {
+				if(gStateCounter >= 48) {
+					gStateCounter = 0;
+					gState = 0;
+					gStepLengthSamples = kStepLengthSlow;
+				}				
+			}
+			else {
+				if(gStateCounter >= 16) {
+					gStateCounter = 0;
+					gState++;
+					if(gState & 1)
+						gServoCounter = 120;
+					else
+						gServoCounter = 80;
+					if(gState == kStateSpin)
+						gStepLengthSamples = kStepLengthFast;
+				}
+			}
+			
+			gStepCounter = 0;
+		}
+	}
+}
+
+// cleanup() is called once at the end, after the audio has stopped.
+// Release any resources that were allocated in setup().
+
+void cleanup(BeagleRTContext *context, void *userData)
+{
+	
+}