PSoC - based Audio Analyzer

Main Loop
The pseudo code for the main loop is:

Main:
	Initialize and start PRS Initialize and start clocks Initialize Variables Start DAC Start Amplifiers Start DELSIG8 Set MIC AMP input to AGND Set Autozero flag

Loop:
	If BPF period is complete
		Save current peak value Average eight previous peaks Select bar graph symbol Load new values for next BPF If Autozero AND all offsets are measured
			Save Offset Values Clear Autozero Flag Set MIC AMP to P01
		Set peak value to zero
	If A/D reading available
		If Filter has settled
			Subtract offset from sample value Perform absolute value if negative If new value is > than last peak
				Save new peak

Timer Tick
The Pseudo code for the Timer Tick which occurs 40000 times per second is:

Get lower six bits of 16-bit PRS Write six bit value to DAC6 Decrement BPF_Counter If BPF_Counter =0
	Load BPF_Counter with Count Value (4)

	Decrement BPF_Timer

	If BPF_Timer =0
		Load parameters for next filter

		If Filter 0-3
			Set Mux to 2Khz Filter

		Else
			Set Mux to no Filter

		Increment Filter Index Load BPF_Timer with Filter-Specific Value Load Settling_Timer with Filter-Specific Value Clear SAMPLE flag

	Else
		If SAMPLE=FALSE
			Decrement Settling_Timer If Settling Timer = 0 Set SAMPLE flag

Decrement Disp_Timer

If Disp_Timer = 0
	Load Disp_Timer with Count Value (50) Drive next column in display with bargraph pattern

Note that the Timer Tick occurs at 40Khz, the BPF event occurs at 10Khz, and the Display Event occurs at 800Hz. Since the display has eight columns, the refresh rate is 100Hz.

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