Add I2S prefill & multisegment parallel output (#17)

* Add parallel output mode for segments

* Use snprintf

* Better statistics update

* Critical fixes. Add a semaphore. (WIP)

* Update benchmark results

* Increase buffer

* Update README.md

* Switch ESP32-S2 single segment to I2S

* Improved statistics formatting

* Minor changes

* Increase priority

* Final changes

* Version

* Upgrade to v9 protocol

Author: awawa-dev

MakunaNeoPixelBusLicence.txt

@@ -18,7 +18,7 @@ RGB to RGBW conversion is calibrated for the neutral white channel BTF SK6812 bu
 
 # Example of supported boards
 
-**ESP32 MH-ET Live (CH9102x/CP2104) and ESP32-S2 Lolin mini (CDC)**  
+**ESP32 MH-ET Live (CP2104 or CH9102x: for Windows you may need CH343CDC driver from *wch* website) and ESP32-S2 Lolin mini (CDC)**  
 <p align="center">
 <img src="https://user-images.githubusercontent.com/69086569/207587620-1c4c53c8-426c-486e-a6d9-d429fd1b050d.png" /><img src="https://user-images.githubusercontent.com/69086569/207587635-b7816329-0e29-47ee-a75a-bc6c41cdc51f.png" />
 </p>
@@ -60,7 +60,7 @@ Enabling `White channel calibration` is optional, if you want to fine tune the w
 # Compiling
 
 Currently we use PlatformIO to compile the project. Install [Visual Studio Code](https://code.visualstudio.com/) and add [PlatformIO plugin](https://platformio.org/).
-This environment will take care of everything and compile the firmware for you. Low-level LED strip support is provided by the https://github.com/Makuna/NeoPixelBus library.
+This environment will take care of everything and compile the firmware for you. Low-level LED strip support is provided by my highly optimizated (pre-fill I2S DMA modes, turbo I2S parallel mode for up to 2 segments etc) version of Neopixelbus library: [link](https://github.com/awawa-dev/NeoPixelBus).
 
 But there is also an alternative and an easier way. Just fork the project and enable its Github Action. Use the online editor to make changes to the ```platformio.ini``` file, for example change default pin-outs/speed or enable multi-segments support, and save it. Github Action will compile new firmware automatically in the Artifacts archive. It has never been so easy!
 
@@ -100,23 +100,23 @@ build_flags = -DNEOPIXEL_RGB -DDATA_PIN=2 ${env.build_flags} -DSECOND_SEGMENT_ST
 
 # Some benchmark results
 
-ESP32 MH-ET LIVE mini is capable of 4Mb serial port speed and ESP32-S2 lolin mini is capable of 5Mb. But to give equal chances all models were tested using the default speed of 2Mb.
+ESP32 MH-ET LIVE mini is capable of 4Mb serial port speed and ESP32-S2 lolin mini is capable of 5Mb. But to give equal chances for a single-segment mode all models were tested using the default speed of 2Mb which should saturate Neopixel data line. Parallel multi-segment mode uses the highest option available because communication performance is critical here.
 
-## Multi-segments can double your large sk6812/ws2812b setup refresh rate for free. All you need is to properly project & construct the LED strip and use HyperSerialESP32 v8.
+## Parallel multi-segments can double your large sk6812/ws2812b setup refresh rate for free. All you need is to properly project & construct the LED strip and use HyperSerialESP32 v9. Parallel communication provides perfect synchronization between Neopixel segments.
 
-| LED strip / Device                                                               | ESP32<br>MH-ET LIVE mini |
-|----------------------------------------------------------------------------------|--------------------------|
-| 300LEDs<br>Refresh rate/continues output=100Hz<br>SECOND_SEGMENT_START_INDEX=150 |            93-97         |
-| 600LEDs<br>Refresh rate/continues output=100Hz<br>SECOND_SEGMENT_START_INDEX=300 |            78-79         |
-| 900LEDs<br>Refresh rate/continues output=100Hz<br>SECOND_SEGMENT_START_INDEX=450 |            55-56         |
+| LED strip / Device                                                                      | ESP32<br>MH-ET LIVE mini @ 4Mb speed |  ESP32-S2<br>  Lolin mini @ 5Mb speed   |
+|-----------------------------------------------------------------------------------------|--------------------------|------------------------------|
+| 300LEDs sk6812<br>Refresh rate/continues output=100Hz<br>SECOND_SEGMENT_START_INDEX=150 |             100          |               100            |
+| 600LEDs sk6812<br>Refresh rate/continues output=100Hz<br>SECOND_SEGMENT_START_INDEX=300 |              83          |                82            |
+| 900LEDs sk6812<br>Refresh rate/continues output=**60Hz** <br>SECOND_SEGMENT_START_INDEX=450 |            54-56         |             55-56            |
 
-## Comparing v6.1 and v8 version (single segment) refresh rate using MH-ET LIVE mini
+## Comparing v6.1 and v9 version (single segment) refresh rate using MH-ET LIVE mini
 
-| LED strip / Device                             | ESP32<br>MH-ET LIVE mini<br>HyperSerialESP32 v6.1 | ESP32<br>MH-ET LIVE mini<br>HyperSerialESP32 v8 |
+| LED strip / Device                             | ESP32<br>MH-ET LIVE mini<br>HyperSerialESP32 v6.1 | ESP32<br>MH-ET LIVE mini<br>HyperSerialESP32 v9 |
 |------------------------------------------------|---------------------------------------------------|-------------------------------------------------|
-| 300LEDs<br>Refresh rate/continues output=100Hz |                       81-83                       |                      80-83                      |
+| 300LEDs<br>Refresh rate/continues output=100Hz |                       81-83                       |                        83                       |
 | 600LEDs<br>Refresh rate/continues output=60Hz  |                       39-40                       |                      41-42                      |
-| 900LEDs<br>Refresh rate/continues output=40Hz  |                       21-26                       |                      26-28                      |
+| 900LEDs<br>Refresh rate/continues output=40Hz  |                       21-26                       |                       28                        |
 
 ## Comparing v6.1 and v8 version (single segment) refresh rate using generic ESP32 with CH340C
 
@@ -134,8 +134,3 @@ ESP32 MH-ET LIVE mini is capable of 4Mb serial port speed and ESP32-S2 lolin min
 | 600LEDs<br>Refresh rate/continues output=60Hz  |                     42                     |
 | 900LEDs<br>Refresh rate/continues output=40Hz  |                    27-28                   |
 
-# Disclaimer
-  
-You use it on your own risk.  
-Don't touch these firmwares if you don't know how to put the device in the programming mode if something goes wrong.  
-As per the MIT license, I assume no liability for any damage to you or any other person or equipment.  

README.md

@@ -28,6 +28,8 @@
 #ifndef BASE_H
 #define BASE_H
 
+#include "freertos/semphr.h"
+
 #if defined(SECOND_SEGMENT_START_INDEX) 
 	#if !defined(SECOND_SEGMENT_DATA_PIN)
 		#error "Please define SECOND_SEGMENT_DATA_PIN for second segment"
@@ -49,13 +51,16 @@ class Base
 
 	public:
 		// static data buffer for the loop
-		uint8_t buffer[MAX_BUFFER];
+		uint8_t buffer[MAX_BUFFER + 1] = {0};
 		// handle to tasks
-		TaskHandle_t processTaskHandle;
+		TaskHandle_t processDataHandle = nullptr;
+		TaskHandle_t processSerialHandle = nullptr;
+		// semaphore to synchronize them
+		xSemaphoreHandle i2sXSemaphore;
 		// current queue position
-		uint16_t queueCurrent = 0;
+		volatile int queueCurrent = 0;
 		// queue end position
-		volatile uint16_t queueEnd = 0;
+		volatile int queueEnd = 0;
 
 		inline int getLedsNumber()
 		{
@@ -128,6 +133,11 @@ class Base
 			return readyToRender;
 		}
 
+		inline void dropLateFrame()
+		{			
+			readyToRender = false;
+		}		
+
 		inline void renderLeds(bool newFrame)
 		{
 			if (newFrame)

include/base.h

@@ -119,15 +119,10 @@ class CalibrationConfig
 		 */
 		void printCalibration()
 		{
-			#ifdef SerialPort			
-				SerialPort.write("\r\nRGBW => Gain: ");
-				SerialPort.print(gain);
-				SerialPort.write("/255, red: ");
-				SerialPort.print(red);
-				SerialPort.write(" , green: ");
-				SerialPort.print(green);
-				SerialPort.write(" , blue: ");
-				SerialPort.print(blue);
+			#ifdef SerialPort
+				char output[128];	
+				snprintf(output, sizeof(output),"RGBW => Gain: %i/255, red: %i, green: %i, blue: %i\r\n", gain, red, green, blue);
+				SerialPort.print(output);
 			#endif
 		}
 } calibrationConfig;

include/calibration.h

@@ -58,7 +58,7 @@ enum class AwaProtocol
  */
 class
 {
-	AwaProtocol state = AwaProtocol::HEADER_A;
+	volatile AwaProtocol state = AwaProtocol::HEADER_A;
 	bool protocolVersion2 = false;
 	uint8_t CRC = 0;
 	uint16_t count = 0;
@@ -85,6 +85,7 @@ class
 			fletcher2 = 0;
 			fletcherExt = 0;
 			position = 0;
+			base.dropLateFrame();
 		}
 
 		/**