Update content.md

Author: karlsoderby

content/hardware/10.mega/boards/giga-r1-wifi/tutorials/giga-audio/content.md

@@ -1,6 +1,6 @@
 ---
 title: Guide to GIGA R1 Advanced ADC/DAC and Audio Features
-description: "Learn how to use the ADC/DAC features, along with useful examples on how to generate waveforms and play audio from a file."
+description: 'Learn how to use the ADC/DAC features, along with useful examples on how to generate waveforms and play audio from a file.'
 author: José Bagur, Taddy Chung & Karl Söderby
 hardware:
   - hardware/10.mega/boards/giga-r1-wifi
@@ -11,16 +11,15 @@ software:
 tags: [ADC, DAC, Audio, USB]
 ---
 
-In the GIGA R1, you can find the powerful STM32H747XI, a dual-core 32-bit Arm® Cortex® microcontroller from STMicroelectronics; this is the same microcontroller found in the [Portenta H7](/hardware/portenta-h7) board.
+In the GIGA R1, you can find the powerful STM32H747XI, a dual-core 32-bit Arm® Cortex® microcontroller from STMicroelectronics; this is the same microcontroller found in the [Portenta H7](/hardware/portenta-h7) board. 
 
 In this guide, we will focus on the advanced ADC/DAC features, utilizing the [Arduino_AdvancedAnalog](https://github.com/arduino-libraries/Arduino_AdvancedAnalog) library. The examples found in this guide can be used to:
-
-- Set up and read ADCs with specific parameters (resolution, sample rate, number of samples per channel, queue depth).
-- Set up and write to a DAC channel with specific parameters (resolution, frequency, number of samples per channel, queue depth).
+- Set up and read ADCs with specific parameters (resolution, sample rate, number of samples per channel, queue depth). 
+- Set up and write to a DAC channel with specific parameters (resolution, frequency, number of samples per channel, queue depth). 
 - Generate specific waveforms through input via serial commands (triangle, square, sine, sawtooth waves) as well as adjusting the frequency.
 - Read and play audio files (`.wav`) from a USB stick (connected to USB-A) to a speaker, using the audio jack.
 
-**_Important note: the GIGA R1 does NOT have an amplifying circuit onboard. Connecting speakers that does not have an amplifier can damage the DAC and the board itself._**
+***Important note: the GIGA R1 does NOT have an amplifying circuit onboard. Connecting speakers that does not have an amplifier can damage the DAC and the board itself.***
 
 ## Hardware & Software Needed
 
@@ -170,7 +169,7 @@ A digital-to-analog converter (DAC) is a device that has a function opposite to
 
 - 8-bit or 12-bit monotonic output
 - Left or right data alignment in 12-bit mode
-- Dual DAC channel independent or simultaneous conversions
+- Dual DAC channel independent or simultaneous conversions 
 - DMA capability for each channel
 - External triggers for conversion
 - Input voltage reference or internal voltage reference
@@ -261,15 +260,15 @@ void setup() {
 
 void dac_output_sq(AdvancedDAC &dac_out) {
     if (dac_out.available()) {
-
+      
         // Get a free buffer for writing.
         SampleBuffer buf = dac_out.dequeue();
-
+        
         // Write data to buffer.
         for (int i=0; i<buf.size(); i++) {
           buf.data()[i] =  (i % 2 == 0) ? 0: 0xfff;
         }
-
+        
         // Write the buffer to DAC.
         dac_out.write(buf);
     }
@@ -349,8 +348,8 @@ AdvancedDAC dac0(A12);
 uint8_t SAMPLES_BUFFER[N_SAMPLES];
 size_t dac_frequency = DEFAULT_FREQUENCY;
 
-void generate_waveform(int cmd)
-{
+void generate_waveform(int cmd) 
+{   
     switch (cmd) {
         case 't':
             // Triangle wave
@@ -387,29 +386,29 @@ void generate_waveform(int cmd)
         case '+':
         case '-':
             Serial.print("Current frequency: ");
-
+            
             if (cmd == '+' && dac_frequency < 64000) {
               dac_frequency *= 2;
             } else if (cmd == '-' && dac_frequency > 1000) {
               dac_frequency /= 2;
             } else {
               break;
             }
-
+            
             dac0.stop();
             delay(500);
             if (!dac0.begin(AN_RESOLUTION_8, dac_frequency * N_SAMPLES, N_SAMPLES, 32)) {
               Serial.println("Failed to start DAC1 !");
             }
             delay(500);
             break;
-
+            
         default:
             Serial.print("Unknown command ");
             Serial.println((char) cmd);
             return;
     }
-
+    
     Serial.print(dac_frequency/1000);
     Serial.println("KHz");
 }
@@ -421,17 +420,17 @@ void setup() {
 
     }
 
-
+    
     Serial.println("Enter a command:");
     Serial.println("t: Triangle wave");
     Serial.println("q: Square wave");
     Serial.println("s: Sine wave");
     Serial.println("r: Sawtooth wave");
     Serial.println("+: Increase frequency");
     Serial.println("-: Decrease frequency");
-
+    
     generate_waveform('s');
-
+    
     // DAC initialization
     if (!dac0.begin(AN_RESOLUTION_8, DEFAULT_FREQUENCY * N_SAMPLES, N_SAMPLES, 32)) {
         Serial.println("Failed to start DAC1 !");
@@ -445,8 +444,8 @@ void loop() {
         if (cmd != '\n') {
           generate_waveform(cmd);
         }
-    }
-
+    } 
+    
     if (dac0.available()) {
         // Get a free buffer for writing.
         SampleBuffer buf = dac0.dequeue();
@@ -463,23 +462,22 @@ void loop() {
 
 ## Audio Playback
 
-The GIGA R1 12-bit DAC channels can also be used to read `.wav` files from a USB stick and stream them directly to a speaker.
+The GIGA R1 12-bit DAC channels can also be used to read `.wav` files from a USB stick and stream them directly to a speaker. 
 
 For this example, you will need:
-
 - A speaker, that has a built in amplifier.
 - A USB mass storage device (USB stick).\*
 - [Arduino_USBHostMbed5](https://github.com/arduino-libraries/Arduino_USBHostMbed5) library installed.
 
-**_\*USB mass storage devices connected needs to be formatted with the FAT32 as a file system, using the MBR partitioning scheme. Read more in the [USB Mass Storage](/tutorials/giga-r1-wifi/giga-usb/#usb-mass-storage) section._**
+***\*USB mass storage devices connected needs to be formatted with the FAT32 as a file system, using the MBR partitioning scheme. Read more in the [USB Mass Storage](/tutorials/giga-r1-wifi/giga-usb/#usb-mass-storage) section.***
 
 ### USB Stick Configuration
 
-The **Arduino_AdvancedAnalog** library contains the necessary functions that enable us to use the advanced capabilities of the GIGA R1 DACs.
+The **Arduino_AdvancedAnalog** library contains the necessary functions that enable us to use the advanced capabilities of the GIGA R1 DACs. 
 
-To read `.wav` files from the USB stick we are using the **Arduino_USBHostMbed5** library. It is important that the USB stick is formatted properly, and that we define its name in the sketch. In this case, we name it `USB_DRIVE`, and is defined like this:
+To read `.wav` files from the USB stick we are using the **Arduino_USBHostMbed5** library. It is important that the USB stick is formatted properly, and that we define its name in the sketch. In this case, we name it `USB_DRIVE`, and is defined like this: 
 
-```arduino
+```arduino 
 mbed::FATFileSystem usb("USB_DRIVE");
 ```
 
@@ -663,7 +661,7 @@ This example is similar to the **Play Single Audio File** example, but with some
 
 - This example uses multiple audio files.
 - The file read is moved to a separate function, `configFile()`, as it will be continuously called from the sketch.
-- Instead of playing a file once, it keeps looping it.
+- Instead of playing a file once, it keeps looping it. 
 - The **BOOT0** (`PC_13`) button (right next to the audio jack) is used as a regular pushbutton to loop through the audio files.
 - Pressing the button changes the file played.
 
@@ -919,4 +917,4 @@ void onPDMdata() {
   PDM.read(sampleBuffer, bytesAvailable);
   samplesRead = bytesAvailable / 2;
 }
-```
+```