Modified freq calculation

README.md

@@ -1,5 +1,6 @@
 # DLO-138
 An open source firmware for DSO-138 Oscilloscope. 
+![Photo](https://github.com/ardyesp/DLO-138/blob/master/pics/pic1.png)
 
 DSO-138 is an excellent piece of hardware based on ARM Cortex M3 core STM32F103 processor and sufficient for most beginner users. The stock firmware, while quite responsive, can use a few improvements. The main shortcoming which prompted the development of DLO-138 firmware is the inability to get waveform data into a computer for further analysis and the lack of a second channel. Engineers troubleshooting hardware issues need to mark reference points on waveform so having another analog or digital channel can greatly improve analysis. This firmware hopes to improve on these issues.
 

capture.ino

@@ -161,7 +161,7 @@ void startSampling(int16_t lDelay)	{
 
 	if(lDelay < 0)	{
 
-			asm volatile(
+		asm volatile(
 			"	ldrh r9, [%[sIndex]]			\n\t"	// load sIndex value
 
 			"top_1:								\n\t"
@@ -184,9 +184,9 @@ void startSampling(int16_t lDelay)	{
 			"	bne notOverflowed_1				\n\t"
 			"	mov r9, #0						\n\t"	// sIndex = 0;
 
-			"	stmfd sp!,{r0, r1, r9, %[keepSampling], %[sIndex], %[triggered], %[ch1], %[ch2], %[dCH], %[lCtr]}	\n\t"
+			"	stmfd sp!,{r9, %[keepSampling], %[sIndex], %[triggered], %[ch1], %[ch2], %[dCH], %[lCtr]}	\n\t"
 			"	bl %[snapMicros]				\n\t"	// micros() - r0 contains the 32bit result
-			"	ldmfd sp!,{r0, r1, r9, %[keepSampling], %[sIndex], %[triggered], %[ch1], %[ch2], %[dCH], %[lCtr]}	\n\t"
+			"	ldmfd sp!,{r9, %[keepSampling], %[sIndex], %[triggered], %[ch1], %[ch2], %[dCH], %[lCtr]}	\n\t"
 
 			"notOverflowed_1:					\n\t"
 			"	strh r9, [%[sIndex]]			\n\t"	// save sIndex
@@ -246,9 +246,9 @@ void startSampling(int16_t lDelay)	{
 			"	bne notOverflowed_2				\n\t"
 			"	mov r9, #0						\n\t"	// sIndex = 0;
 
-			"	stmfd sp!,{r0, r1, r9, %[keepSampling], %[sIndex], %[triggered], %[ch1], %[ch2], %[dCH], %[lCtr]}	\n\t"
+			"	stmfd sp!,{r9, %[keepSampling], %[sIndex], %[triggered], %[ch1], %[ch2], %[dCH], %[lCtr]}	\n\t"
 			"	bl %[snapMicros]				\n\t"	// micros() - r0 contains the 32bit result
-			"	ldmfd sp!,{r0, r1, r9, %[keepSampling], %[sIndex], %[triggered], %[ch1], %[ch2], %[dCH], %[lCtr]}	\n\t"
+			"	ldmfd sp!,{r9, %[keepSampling], %[sIndex], %[triggered], %[ch1], %[ch2], %[dCH], %[lCtr]}	\n\t"
 
 			"notOverflowed_2:					\n\t"
 			"	strh r9, [%[sIndex]]			\n\t"	// save sIndex
@@ -308,9 +308,9 @@ void startSampling(int16_t lDelay)	{
 			"	bne notOverflowed_3				\n\t"
 			"	mov r9, #0						\n\t"	// sIndex = 0;
 
-			"	stmfd sp!,{r0, r1, r9, %[keepSampling], %[sIndex], %[triggered], %[ch1], %[ch2], %[dCH], %[lCtr], %[tDelay]}	\n\t"
+			"	stmfd sp!,{r9, %[keepSampling], %[sIndex], %[triggered], %[ch1], %[ch2], %[dCH], %[lCtr], %[tDelay]}	\n\t"
 			"	bl %[snapMicros]				\n\t"	// micros() - r0 contains the 32bit result
-			"	ldmfd sp!,{r0, r1, r9, %[keepSampling], %[sIndex], %[triggered], %[ch1], %[ch2], %[dCH], %[lCtr], %[tDelay]}	\n\t"
+			"	ldmfd sp!,{r9, %[keepSampling], %[sIndex], %[triggered], %[ch1], %[ch2], %[dCH], %[lCtr], %[tDelay]}	\n\t"
 
 			"notOverflowed_3:					\n\t"
 			"	strh r9, [%[sIndex]]			\n\t"	// save sIndex

display.ino

@@ -624,8 +624,8 @@ void calculateStats()	{
 	}
 
 	// find out frequency
-	uint16_t Vavr = freqSumSamples/NUM_SAMPLES;
-	boolean dnWave = (ch1Capture[sIndex] < Vavr);
+	uint16_t fVavr = freqSumSamples/NUM_SAMPLES;
+	boolean dnWave = (ch1Capture[sIndex] < fVavr - 10);
 	boolean firstOne = true;
 	uint16_t cHigh = 0;
 
@@ -640,7 +640,7 @@ void calculateStats()	{
 			k = 0;
 
 		// mark the points where wave transitions the average value
-		if(dnWave && (ch1Capture[k] > Vavr))	{
+		if(dnWave && (ch1Capture[k] > fVavr + 10))	{
 			if(!firstOne)	{
 				sumCW += (sCtr - cHigh);
 				numCycles++;
@@ -652,7 +652,7 @@ void calculateStats()	{
 			cHigh = sCtr;
 		}
 
-		if(!dnWave && (ch1Capture[k] < Vavr))	{
+		if(!dnWave && (ch1Capture[k] < fVavr - 10))	{
 			if(!firstOne)	{
 				sumPW += (sCtr - cHigh);
 				numHCycles++;