Simplify & document SGTL5000 control

analyze_fft256.h

 		return (float)sum * (1.0 / 16384.0);
 	}
 	void averageTogether(uint8_t n) {
-		if (n == 0) n == 1;
+		if (n == 0) n = 1;
 		naverage = n;
 	}
 	void windowFunction(const int16_t *w) {

control_sgtl5000.cpp

 	return val1;
 }
 
-unsigned short AudioControlSGTL5000::route(uint8_t i2s_out, uint8_t dac, uint8_t dap, uint8_t dap_mix)
-{
-	i2s_out&=3;
-	dac&=3;
-	dap&=3;
-	dap_mix&=3;
-	if((i2s_out==SGTL_AUDIO_PROCESSOR)||(dac==SGTL_AUDIO_PROCESSOR)) modify(DAP_CONTROL,1,1); // enable DAP
-	return modify(CHIP_SSS_CTRL,(dap_mix<<8)|(dap<<6)|(dac<<4)|i2s_out,(3<<8)|(3<<6)|(3<<4)|3);
-}
-
 bool AudioControlSGTL5000::volumeInteger(unsigned int n)
 {
 	if (n == 0) {
 
 unsigned short AudioControlSGTL5000::dacVolume(float n) // set both directly
 {
-	if(read(CHIP_ADCDAC_CTRL)&(3<<2)!=((n>0 ? 0:3)<<2)) modify(CHIP_ADCDAC_CTRL,(n>0 ? 0:3)<<2,3<<2);
+	if ((read(CHIP_ADCDAC_CTRL)&(3<<2)) != ((n>0 ? 0:3)<<2)) {
+		modify(CHIP_ADCDAC_CTRL,(n>0 ? 0:3)<<2,3<<2);
+	}
 	unsigned char m=calcVol(n,0xC0);
 	return modify(CHIP_DAC_VOL,((0xFC-m)<<8)|(0xFC-m),65535);
 }
 unsigned short AudioControlSGTL5000::dacVolume(float left, float right)
 {
 	unsigned short adcdac=((right>0 ? 0:2)|(left>0 ? 0:1))<<2;
-	if(read(CHIP_ADCDAC_CTRL)&(3<<2)!=adcdac)  modify(CHIP_ADCDAC_CTRL,adcdac,1<<2);
+	if ((read(CHIP_ADCDAC_CTRL)&(3<<2)) != adcdac) {
+		modify(CHIP_ADCDAC_CTRL,adcdac,1<<2);
+	}
 	unsigned short m=(0xFC-calcVol(right,0xC0))<<8|(0xFC-calcVol(left,0xC0));
 	return modify(CHIP_DAC_VOL,m,65535);
 }
 
-unsigned short AudioControlSGTL5000::adcHighPassFilterControl(uint8_t bypass, uint8_t freeze)
+unsigned short AudioControlSGTL5000::adcHighPassFilterEnable(void)
 {
-	return modify(CHIP_ADCDAC_CTRL, (freeze&1)<<1|bypass&1,3);
+	return modify(CHIP_ADCDAC_CTRL, 0, 3);
 }
 
-unsigned short AudioControlSGTL5000::adcHighPassFilterControl(uint8_t bypass)
+unsigned short AudioControlSGTL5000::adcHighPassFilterFreeze(void)
 {
-	return modify(CHIP_ADCDAC_CTRL, bypass&1,1);
+	return modify(CHIP_ADCDAC_CTRL, 2, 3);
+}
+
+unsigned short AudioControlSGTL5000::adcHighPassFilterDisable(void)
+{
+	return modify(CHIP_ADCDAC_CTRL, 1, 3);
 }
 
 
 // DAP_CONTROL
-unsigned short AudioControlSGTL5000::audioMixerEnable(uint8_t n)
+
+unsigned short AudioControlSGTL5000::audioPreProcessorEnable(void)
 {
-	return modify(DAP_CONTROL,(n&1)<<4,1<<4);
+	// audio processor used to pre-process analog input before Teensy
+	return write(DAP_CONTROL, 1) && write(CHIP_SSS_CTRL, 0x0013);
 }
-unsigned short AudioControlSGTL5000::audioProcessorEnable(uint8_t n)
+
+unsigned short AudioControlSGTL5000::audioPostProcessorEnable(void)
 {
-	if(n) n=1;
-	unsigned char i2s_sel=3*n; // ADC if n==0 else DAP
-	modify(DAP_CONTROL,n,1);
-	return route(i2s_sel,SGTL_I2S_TEENSY,SGTL_ADC);
+	// audio processor used to post-process Teensy output before headphones/lineout
+	return write(DAP_CONTROL, 1) && write(CHIP_SSS_CTRL, 0x0070);
 }
 
-unsigned short AudioControlSGTL5000::audioProcessorEnable(void)
+unsigned short AudioControlSGTL5000::audioProcessorDisable(void)
 {
-	return audioProcessorEnable(1);
+	return write(CHIP_SSS_CTRL, 0x0010) && write(DAP_CONTROL, 0);
 }
 
+
 // DAP_PEQ
 unsigned short AudioControlSGTL5000::eqFilterCount(uint8_t n) // valid to n&7, 0 thru 7 filters enabled.
 {
 */
 unsigned short AudioControlSGTL5000::autoVolumeControl(uint8_t maxGain, uint8_t lbiResponse, uint8_t hardLimit, float threshold, float attack, float decay)
 {
-	if(semi_automated&&(!read(DAP_CONTROL)&1)) audioProcessorEnable(1);
+	//if(semi_automated&&(!read(DAP_CONTROL)&1)) audioProcessorEnable();
 	if(maxGain>2) maxGain=2;
 	lbiResponse&=3;
 	hardLimit&=1;
 	write(DAP_AVC_DECAY,dec);
 	return 	modify(DAP_AVC_CTRL,maxGain<<12|lbiResponse<<8|hardLimit<<5,3<<12|3<<8|1<<5);
 }
-unsigned short AudioControlSGTL5000::autoVolumeEnable(uint8_t n)
+unsigned short AudioControlSGTL5000::autoVolumeEnable(void)
 {
-	n&=1;
-	return modify(DAP_AVC_CTRL,n,1);
+	return modify(DAP_AVC_CTRL, 1, 1);
 }
-unsigned short AudioControlSGTL5000::autoVolumeEnable(void)
+unsigned short AudioControlSGTL5000::autoVolumeDisable(void)
 {
-	return modify(DAP_AVC_CTRL,1,1);
+	return modify(DAP_AVC_CTRL, 0, 1);
 }
 
 unsigned short AudioControlSGTL5000::enhanceBass(float lr_lev, float bass_lev)
 {
-	return modify(DAP_BASS_ENHANCE_CTRL,(0x3F-calcVol(lr_lev,0x3F))<<8|0x7F-calcVol(bass_lev,0x7F),0x3F<<8|0x7F);
+	return modify(DAP_BASS_ENHANCE_CTRL,((0x3F-calcVol(lr_lev,0x3F))<<8) | (0x7F-calcVol(bass_lev,0x7F)), (0x3F<<8) | 0x7F);
 }
 unsigned short AudioControlSGTL5000::enhanceBass(float lr_lev, float bass_lev, uint8_t hpf_bypass, uint8_t cutoff)
 {
 	modify(DAP_BASS_ENHANCE,(hpf_bypass&1)<<8|(cutoff&7)<<4,1<<8|7<<4);
 	return enhanceBass(lr_lev,bass_lev);
 }
-unsigned short AudioControlSGTL5000::enhanceBassEnable(uint8_t n)
+unsigned short AudioControlSGTL5000::enhanceBassEnable(void)
 {
-	return modify(DAP_BASS_ENHANCE,n&1,1);
+	return modify(DAP_BASS_ENHANCE, 1, 1);
 }
-unsigned short AudioControlSGTL5000::enhanceBassEnable(void)
+unsigned short AudioControlSGTL5000::enhanceBassDisable(void)
 {
-	return enhanceBassEnable(1);
+	return modify(DAP_BASS_ENHANCE, 0, 1);
 }
 unsigned short AudioControlSGTL5000::surroundSound(uint8_t width)
 {
 }
 unsigned short AudioControlSGTL5000::surroundSound(uint8_t width, uint8_t select)
 {
-	return modify(DAP_SGTL_SURROUND,(width&7)<<4|select&3,7<<4|3);
+	return modify(DAP_SGTL_SURROUND,((width&7)<<4)|(select&3), (7<<4)|3);
 }
-unsigned short AudioControlSGTL5000::surroundSoundEnable(uint8_t n)
+unsigned short AudioControlSGTL5000::surroundSoundEnable(void)
 {
-	if(n) n=3;
-	return modify(DAP_SGTL_SURROUND,n,3);
+	return modify(DAP_SGTL_SURROUND, 3, 3);
 }
-unsigned short AudioControlSGTL5000::surroundSoundEnable(void)
+unsigned short AudioControlSGTL5000::surroundSoundDisable(void)
 {
-	surroundSoundEnable(1);
+	return modify(DAP_SGTL_SURROUND, 0, 3);
 }
 
 unsigned char AudioControlSGTL5000::calcVol(float n, unsigned char range)
 
 void AudioControlSGTL5000::automate(uint8_t dap, uint8_t eq)
 {
-	if((dap!=0)&&(!read(DAP_CONTROL)&1)) audioProcessorEnable(1);
-	if(read(DAP_AUDIO_EQ)&3!=eq) eqSelect(eq);
+	//if((dap!=0)&&(!(read(DAP_CONTROL)&1))) audioProcessorEnable();
+	if((read(DAP_AUDIO_EQ)&3) != eq) eqSelect(eq);
 }
 
 void AudioControlSGTL5000::automate(uint8_t dap, uint8_t eq, uint8_t filterCount)
 {
 	automate(dap,eq);
-	if(filterCount>read(DAP_PEQ)&7) eqFilterCount(filterCount);
+	if (filterCount > (read(DAP_PEQ)&7)) eqFilterCount(filterCount);
 }
 
 
   float A;
   if(filtertype<FILTER_PARAEQ) A=pow(10,dB_Gain/20); else A=pow(10,dB_Gain/40);
   float W0 = 2*3.14159265358979323846*fC/fS; 
-  float cosw=cos(W0);
-  float sinw=sin(W0);
+  float cosw=cosf(W0);
+  float sinw=sinf(W0);
   //float alpha = sinw*sinh((log(2)/2)*BW*W0/sinw);
   //float beta = sqrt(2*A);
   float alpha = sinw / (2 * Q); 
-  float beta = sqrt(A)/Q;
+  float beta = sqrtf(A)/Q;
   float b0,b1,b2,a0,a1,a2;
 
   switch(filtertype) {
     a0 = (A+1.0F) - ((A-1.0F)*cosw) + (beta*sinw);
     a1 = -2.0F * ((A-1.0F) - ((A+1.0F)*cosw));
     a2 = -((A+1.0F) - ((A-1.0F)*cosw) - (beta*sinw));
+  default:
+    b0 = 0.5;
+    b1 = 0.0;
+    b2 = 0.0;
+    a0 = 1.0;
+    a1 = 0.0;
+    a2 = 0.0;
   }
 
   a0=(a0*2)/(float)quantization_unit; // once here instead of five times there...

control_sgtl5000.h

 
 #include "AudioControl.h"
 
-#define SGTL_ADC 0
-#define SGTL_I2S_TEENSY 1
-#define SGTL_AUDIO_PROCESSOR 3
-
 class AudioControlSGTL5000 : public AudioControl
 {
 public:
 			return false;
 		}
 	}
-	unsigned short route(uint8_t i2s_out, uint8_t dac, uint8_t dap, uint8_t dap_mix);
-	unsigned short route(uint8_t i2s_out, uint8_t dac, uint8_t dap) { return route(i2s_out,dac,dap,0); }
 	bool volume(float left, float right);
 	bool micGain(unsigned int dB);
 	bool lineInLevel(uint8_t n) { return lineInLevel(n, n); }
 	unsigned short lineOutLevel(uint8_t left, uint8_t right);
 	unsigned short dacVolume(float n);
 	unsigned short dacVolume(float left, float right);
-	unsigned short adcHighPassFilterControl(uint8_t bypass, uint8_t freeze);
-	unsigned short adcHighPassFilterControl(uint8_t bypass);
-	unsigned short audioMixerEnable(uint8_t n);
-	unsigned short audioProcessorEnable(uint8_t n);
-	unsigned short audioProcessorEnable(void);
+	unsigned short adcHighPassFilterEnable(void);
+	unsigned short adcHighPassFilterFreeze(void);
+	unsigned short adcHighPassFilterDisable(void);
+	//unsigned short adcHighPassFilterControl(uint8_t bypass, uint8_t freeze);
+	//unsigned short adcHighPassFilterControl(uint8_t bypass);
+	unsigned short audioPreProcessorEnable(void);
+	unsigned short audioPostProcessorEnable(void);
+	unsigned short audioProcessorDisable(void);
 	unsigned short eqFilterCount(uint8_t n);
 	unsigned short eqSelect(uint8_t n);
 	unsigned short eqBand(uint8_t bandNum, float n);
 	void eqBands(float bass, float treble);
 	void eqFilter(uint8_t filterNum, int *filterParameters);
 	unsigned short autoVolumeControl(uint8_t maxGain, uint8_t lbiResponse, uint8_t hardLimit, float threshold, float attack, float decay);
-	unsigned short autoVolumeEnable(uint8_t n);
 	unsigned short autoVolumeEnable(void);
+	unsigned short autoVolumeDisable(void);
 	unsigned short enhanceBass(float lr_lev, float bass_lev);
 	unsigned short enhanceBass(float lr_lev, float bass_lev, uint8_t hpf_bypass, uint8_t cutoff);
-	unsigned short enhanceBassEnable(uint8_t n);
 	unsigned short enhanceBassEnable(void);
+	unsigned short enhanceBassDisable(void);
 	unsigned short surroundSound(uint8_t width);
 	unsigned short surroundSound(uint8_t width, uint8_t select);
-	unsigned short surroundSoundEnable(uint8_t n);
 	unsigned short surroundSoundEnable(void);
+	unsigned short surroundSoundDisable(void);
 	void killAutomation(void) { semi_automated=false; }
 
 protected:

examples/Analysis/FFT/FFT.ino

 }
 
 void loop() {
+  float n;
+  int i;
+
   if (myFFT.available()) {
     // each time new FFT data is available
     // print it all to the Arduino Serial Monitor
     Serial.print("FFT: ");
-    for (int i=0; i<40; i++) {
-      Serial.print(myFFT.read(i));
-      //Serial.print(myFFT.output[i]);
-      Serial.print(" ");
+    for (i=0; i<40; i++) {
+      n = myFFT.read(i);
+      if (n >= 0.01) {
+        Serial.print(n);
+        Serial.print(" ");
+      } else {
+        Serial.print("  -  ");
+      }
     }
     Serial.println();
   }

gui/index.html

 tr.even {background-color:#E0E0E0}
 p.func {padding-bottom:0; margin:0px}
 p.desc {padding-left:2em; margin:0px; padding-top:0.2em; padding-bottom:0.8em; font-size:0.75em}
+pre.desc {padding-left:3em; margin:0px; padding-top:0em; padding-bottom:0.8em; font-size:0.75em;
+	background-color:#FFFFFF; border:0px; line-height:100%;
+}
 span.indent {padding-left:2em}
 span.literal {color: #006699}
 span.comment {color: #777755}

gui/list.html

 		The input number is in decibels, from 0 to 63.
 	</p>
 
-	<h3>Signal Adjustment</h3>
+	<h3>Signal Levels</h3>
 
-	<p>The SGTL5000 supports flexible signal routing (inside the chip) and
-		many optional signal conditioning features.</p>
+	<p>The default signal levels should be used for most applications,
+		but these functions allow you to customize the analog signals.</p>
 
-	<p class=func><span class=keyword>route</span>(i2s, dac, dap);</p>
-	<p class=desc>blah blah blah blah
-	</p>
-	<p class=func><span class=keyword>route</span>(i2s, dac, dap, dapmix);</p>
-	<p class=desc>blah blah blah blah
-	</p>
 	<p class=func><span class=keyword>muteHeadphone</span>();</p>
 	<p class=desc>Silence the headphone output.
 	</p>
 	<p class=func><span class=keyword>unmuteHeadphone</span>();</p>
 	<p class=desc>Turn the headphone output on.
 	</p>
-	<p class=func><span class=keyword>unmuteLineout</span>();</p>
-	<p class=desc>Turn the line level outputs on.
-	</p>
 	<p class=func><span class=keyword>muteLineout</span>();</p>
 	<p class=desc>Silence the line level outputs.
 	</p>
-	<p class=func><span class=keyword>lineInLevel</span>(both);</p>
-	<p class=desc>blah blah blah blah
+	<p class=func><span class=keyword>unmuteLineout</span>();</p>
+	<p class=desc>Turn the line level outputs on.
 	</p>
+	<p class=func><span class=keyword>lineInLevel</span>(both);</p>
+	<p class=desc style="padding-bottom:0.2em;">Adjust the sensitivity of the line-level inputs.
+		Fifteen settings are possible:
+	</p>
+<pre class="desc">
+ 0: 3.12 Volts p-p
+ 1: 2.63 Volts p-p
+ 2: 2.22 Volts p-p
+ 3: 1.87 Volts p-p
+ 4: 1.58 Volts p-p
+ 5: 1.33 Volts p-p  (default)
+ 6: 1.11 Volts p-p
+ 7: 0.94 Volts p-p
+ 8: 0.79 Volts p-p
+ 9: 0.67 Volts p-p
+10: 0.56 Volts p-p
+11: 0.48 Volts p-p
+12: 0.40 Volts p-p
+13: 0.34 Volts p-p
+14: 0.29 Volts p-p
+15: 0.24 Volts p-p
+</pre>
 	<p class=func><span class=keyword>lineInLevel</span>(left, right);</p>
-	<p class=desc>blah blah blah blah
+	<p class=desc>Adjust the sensitivity of the line-level inputs, with different
+		settings for left and right.  The same 15 settings are available.
 	</p>
 	<p class=func><span class=keyword>lineOutLevel</span>(both);</p>
-	<p class=desc>blah blah blah blah
-	</p>
+	<p class=desc style="padding-bottom:0.2em;">Adjust the line level outout voltage range.  The following
+		settings are possible:
+	</p>
+<pre class="desc">
+13: 3.16 Volts p-p
+14: 2.98 Volts p-p
+15: 2.83 Volts p-p
+16: 2.67 Volts p-p
+17: 2.53 Volts p-p
+18: 2.39 Volts p-p
+19: 2.26 Volts p-p
+20: 2.14 Volts p-p
+21: 2.02 Volts p-p
+22: 1.91 Volts p-p
+23: 1.80 Volts p-p
+24: 1.71 Volts p-p
+25: 1.62 Volts p-p
+26: 1.53 Volts p-p
+27: 1.44 Volts p-p
+28: 1.37 Volts p-p
+29: 1.29 Volts p-p  (default)
+30: 1.22 Volts p-p
+31: 1.16 Volts p-p
+</pre>
 	<p class=func><span class=keyword>lineOutLevel</span>(left, right);</p>
-	<p class=desc>blah blah blah blah
+	<p class=desc>Adjust the line level outout voltage range, with separate
+		settings for left and right.  The same settings (13 to 31) are available.
 	</p>
-	<p class=func><span class=keyword>dacVolume</span>(both);</p>
-	<p class=desc>blah blah blah blah
+
+
+	<h3>Signal Conditioning</h3>
+
+	<p>Usually these digital signal conditioning features should be left at their
+		default settings.
 	</p>
-	<p class=func><span class=keyword>dacVolume</span>(left, right);</p>
-	<p class=desc>blah blah blah blah
+
+	<p class=func><span class=keyword>adcHighPassFilterFreeze</span>();</p>
+	<p class=desc>By default, the analog input (either line-level inputs or mic)
+		is high-pass filtered, to remove any DC component.  This function
+		freezes the filter, so the DC component is still substracted, but
+		the filter stops tracking any DC or low frequency changes.
 	</p>
-	<p class=func><span class=keyword>adcHighPassFilterControl</span>(bypass, freeze);</p>
-	<p class=desc>blah blah blah blah
+	<p class=func><span class=keyword>adcHighPassFilterDisable</span>();</p>
+	<p class=desc>Completely disable the analog input filter.  DC and sub-audible
+		low frequencies are allowed to enter the digital signal.
 	</p>
-	<p class=func><span class=keyword>adcHighPassFilterControl</span>(bypass);</p>
-	<p class=desc>blah blah blah blah
+	<p class=func><span class=keyword>adcHighPassFilterEnable</span>();</p>
+	<p class=desc>Turn the DC-blocking filter back on, if disabled, or
+		allows it to resume tracking DC and low frequency changes, if
+		previously frozen.
 	</p>
-	<p class=func><span class=keyword>audioMixerEnable</span>(n);</p>
-	<p class=desc>blah blah blah blah
+	<p class=func><span class=keyword>dacVolume</span>(both);</p>
+	<p class=desc>Normally output volume should be used with volume(), which
+		changes the analog gain in the headphone amplifier.  This function
+		controls digital attenuation before conversion to analog, which
+		reduces resolution, but allows another fine control of output
+		signal level.  The ranges is 0 to 1.0, with the default at 1.0.
+	</p>
+	<p class=func><span class=keyword>dacVolume</span>(left, right);</p>
+	<p class=desc>Adjust the digital output volume separately on left and
+		right channels.
 	</p>
 
+
 	<h3>Audio Processor</h3>
 
-	<p>An optional digital audio processor, capable of implementing a
+	<p>The optional digital audio processor is capable of implementing 
+		automatic volume control, a
 		simple equalizer, filtering, bass enhancement and surround sound
-		is available.  It can process audio input before the SGTL5000
-		sends it by I2S to Teensy, or it can process Teensy's I2S output
-		before converting the digital data to analog signals.</p>
+		is available.
+	</p>
+	<p>These signal processing features are implemented in the SGTL5000 chip,
+		so they do not consume CPU time on Teensy.
+	</p>
 
-	<p class=func><span class=keyword>audioProcessorEnable</span>(n);</p>
-	<p class=desc>blah blah blah blah
+	<p class=func><span class=keyword>audioPreProcessorEnable</span>();</p>
+	<p class=desc>Enable the audio processor to pre-process the input
+		(from either line-level inputs or microphone) before it's sent
+		to Teensy by I2S.
 	</p>
-	<p class=func><span class=keyword>audioProcessorEnable</span>();</p>
-	<p class=desc>blah blah blah blah
+	<p class=func><span class=keyword>audioPostProcessorEnable</span>();</p>
+	<p class=desc>Enable the audio processor to post-process Teensy's
+		I2S output before it's turned into analog signals for the
+		headphones and/or line level outputs.
+	</p>
+	<p class=func><span class=keyword>audioProcessorDisable</span>();</p>
+	<p class=desc>Disable the audio processor.
 	</p>
 	<p class=func><span class=keyword>eqFilterCount</span>(n);</p>
 	<p class=desc>blah blah blah blah
 	<p class=func><span class=keyword>autoVolumeControl</span>(maxGain, response, hardLimit, threshold, attack, decay);</p>
 	<p class=desc>blah blah blah blah
 	</p>
-	<p class=func><span class=keyword>autoVolumeEnable</span>(n);</p>
+	<p class=func><span class=keyword>autoVolumeEnable</span>();</p>
 	<p class=desc>blah blah blah blah
 	</p>
-	<p class=func><span class=keyword>autoVolumeEnable</span>();</p>
+	<p class=func><span class=keyword>autoVolumeDisable</span>();</p>
 	<p class=desc>blah blah blah blah
 	</p>
 	<p class=func><span class=keyword>enhanceBass</span>(lr_lev, bass_lev);</p>
 	<p class=func><span class=keyword>enhanceBass</span>(lr_lev, bass_lev, hpf_bypass, cutoff);</p>
 	<p class=desc>blah blah blah blah
 	</p>
-	<p class=func><span class=keyword>enhanceBassEnable</span>(n);</p>
+	<p class=func><span class=keyword>enhanceBassEnable</span>();</p>
 	<p class=desc>blah blah blah blah
 	</p>
-	<p class=func><span class=keyword>enhanceBassEnable</span>();</p>
+	<p class=func><span class=keyword>enhanceBassDisable</span>();</p>
 	<p class=desc>blah blah blah blah
 	</p>
 	<p class=func><span class=keyword>surroundSound</span>(width);</p>
 	<p class=func><span class=keyword>surroundSound</span>(width, select);</p>
 	<p class=desc>blah blah blah blah
 	</p>
-	<p class=func><span class=keyword>surroundSoundEnable</span>(n);</p>
-	<p class=desc>blah blah blah blah
-	</p>
 	<p class=func><span class=keyword>surroundSoundEnable</span>();</p>
 	<p class=desc>blah blah blah blah
 	</p>
-	<p class=func><span class=keyword>killAutomation</span>();</p>
+	<p class=func><span class=keyword>surroundSoundDisable</span>();</p>
 	<p class=desc>blah blah blah blah
 	</p>
 	<h3>Notes</h3>
-	<p>TODO: how does the input AGC work
-	</p>
-	<p>TODO: document signal routing
-	</p>
-	<p>TODO: line level output adjust is weird arbitrary integers.  Should this be
-		made into more sensible numbers, or do we just document the integer-voltage
-		measurements that correspond to the audio shield's hardware?
-	</p>
-	<p>TODO: make some sense out of the terribly complex audio processor features &amp; options!
-	</p>
-	<p>TODO: can some of these enable functions be eliminated and have those features
-		automatically enabled or disabled depending on whether the route() function has
-		configured signals to/from them?
+	<p>TODO: document the many audio processor features &amp; functions!
 	</p>
 </script>
 <script type="text/x-red" data-template-name="AudioControlSGTL5000">