Christmas DMA core tweaks

Bring back support to change the I2S_NUM_X as a define.

Attempt to reduce buffer swap flicker with some additional checks.

6 files changed, 115 insertions, 69 deletions

diff --git a/ESP32-HUB75-MatrixPanel-I2S-DMA.cpp b/ESP32-HUB75-MatrixPanel-I2S-DMA.cpp
index a82b37f..a9fae2f 100644
--- a/ESP32-HUB75-MatrixPanel-I2S-DMA.cpp
+++ b/ESP32-HUB75-MatrixPanel-I2S-DMA.cpp
@@ -419,7 +419,7 @@ void MatrixPanel_I2S_DMA::configureDMA(const HUB75_I2S_CFG& _cfg)
     Serial.println(F("Performing I2S setup:"));
 #endif
 
-    i2s_parallel_config_t cfg = {
+    i2s_parallel_config_t dma_cfg = {
         .gpio_bus={_cfg.gpio.r1, _cfg.gpio.g1, _cfg.gpio.b1, _cfg.gpio.r2, _cfg.gpio.g2, _cfg.gpio.b2, _cfg.gpio.lat, _cfg.gpio.oe, _cfg.gpio.a, _cfg.gpio.b, _cfg.gpio.c, _cfg.gpio.d, _cfg.gpio.e, -1, -1, -1},
         .gpio_clk=_cfg.gpio.clk,
         .sample_rate=_cfg.i2sspeed,   
@@ -428,18 +428,16 @@ void MatrixPanel_I2S_DMA::configureDMA(const HUB75_I2S_CFG& _cfg)
         .lldesc_a=dmadesc_a,        
         .desccount_b=desccount,
         .lldesc_b=dmadesc_b,
-        .clkphase=_cfg.clkphase
+        .clkphase=_cfg.clkphase,
+		.int_ena_out_eof=_cfg.double_buff
     };
-
-    // Setup I2S 
-    i2s_parallel_driver_install(I2S_NUM_0, &cfg);
-    //i2s_parallel_setup_without_malloc(&I2S1, &cfg);
-
-    // Start DMA Output
-    i2s_parallel_send_dma(I2S_NUM_0, &dmadesc_a[0]);
+	
+    // Setup I2S
+    i2s_parallel_driver_install(ESP32_I2S_DEVICE, &dma_cfg);
+    i2s_parallel_send_dma(ESP32_I2S_DEVICE, &dmadesc_a[0]);
 
     #if SERIAL_DEBUG  
-      Serial.println(F("configureDMA(): DMA setup completed on I2S_NUM_0.")); 
+      Serial.println(F("configureDMA(): DMA setup completed on ESP32_I2S_DEVICE.")); 
     #endif       
 		
 } // end initMatrixDMABuff
diff --git a/ESP32-HUB75-MatrixPanel-I2S-DMA.h b/ESP32-HUB75-MatrixPanel-I2S-DMA.h
index 3ef5713..db508cd 100644
--- a/ESP32-HUB75-MatrixPanel-I2S-DMA.h
+++ b/ESP32-HUB75-MatrixPanel-I2S-DMA.h
@@ -129,9 +129,10 @@
 
 /***************************************************************************************/
 /* Definitions below should NOT be ever changed without rewriting library logic         */
-#define ESP32_I2S_DMA_MODE          I2S_PARALLEL_WIDTH_16    // From esp32_i2s_parallel_v2.h = 16 bits in parallel
+#define ESP32_I2S_DMA_MODE          I2S_PARALLEL_WIDTH_16   // From esp32_i2s_parallel_v2.h = 16 bits in parallel
 #define ESP32_I2S_DMA_STORAGE_TYPE  uint16_t                // DMA output of one uint16_t at a time.
-#define CLKS_DURING_LATCH            0                      // Not (yet) used. 
+#define CLKS_DURING_LATCH           0                       // Not (yet) used. 
+#define ESP32_I2S_DEVICE            I2S_NUM_1
 
 // Panel Upper half RGB (numbering according to order in DMA gpio_bus configuration)
 #define BITS_RGB1_OFFSET 0 // Start point of RGB_X1 bits
@@ -316,7 +317,7 @@ struct  HUB75_I2S_CFG {
       LAT_PIN_DEFAULT, OE_PIN_DEFAULT, CLK_PIN_DEFAULT },
     shift_driver _drv = SHIFTREG,
     bool _dbuff = false,
-    clk_speed _i2sspeed = HZ_20M,
+    clk_speed _i2sspeed = HZ_10M,
     uint8_t _latblk  = 1, // Anything > 1 seems to cause artefacts on ICS panels
     bool _clockphase = true,
     uint8_t _min_refresh_rate = 85
@@ -525,14 +526,22 @@ class MatrixPanel_I2S_DMA {
                 Serial.printf_P(PSTR("Set back buffer to: %d\n"), back_buffer_id);
         #endif      
 
-        i2s_parallel_flip_to_buffer(I2S_NUM_0, back_buffer_id);
-        
+        i2s_parallel_set_previous_buffer_not_free();       
         // Wait before we allow any writing to the buffer. Stop flicker.
         while(i2s_parallel_is_previous_buffer_free() == false) { }       
         
+        i2s_parallel_flip_to_buffer(ESP32_I2S_DEVICE, back_buffer_id);        
         // Flip to other buffer as the backbuffer. 
         // i.e. Graphic changes happen to this buffer, but aren't displayed until flipDMABuffer() is called again.
-        back_buffer_id ^= 1; 
+        back_buffer_id ^= 1;        
+        
+        i2s_parallel_set_previous_buffer_not_free();       
+        // Wait before we allow any writing to the buffer. Stop flicker.
+        while(i2s_parallel_is_previous_buffer_free() == false) { }          
+        
+        
+
+
         
     }
         
@@ -585,7 +594,7 @@ class MatrixPanel_I2S_DMA {
      */
     void stopDMAoutput() {  
         resetbuffers();
-        i2s_parallel_stop_dma(I2S_NUM_0);
+        i2s_parallel_stop_dma(ESP32_I2S_DEVICE);
     } 
     
 
diff --git a/esp32_i2s_parallel_dma.c b/esp32_i2s_parallel_dma.c
index 960fab6..ec6e17b 100644
--- a/esp32_i2s_parallel_dma.c
+++ b/esp32_i2s_parallel_dma.c
@@ -13,6 +13,7 @@
 
 // Header
 #include "esp32_i2s_parallel_dma.h" 
+#include "esp32_i2s_parallel_mcu_def.h"
 
 #include <stdbool.h>
 #include <stdint.h>
@@ -25,22 +26,28 @@
 #include <soc/gpio_sig_map.h>
 
 // For I2S state management.
-static i2s_parallel_state_t *i2s_state 	= NULL;
+static i2s_parallel_state_t *i2s_state  = NULL;
 
 // ESP32-S2,S3,C3 only has IS20
 // Original ESP32 has two I2S's, but we'll stick with the lowest common denominator.
-static i2s_dev_t* I2S 					= &I2S0; // Device to use for this library, change if you want.
+
+#ifdef ESP32_ORIG
+static i2s_dev_t* I2S[I2S_NUM_MAX] = {&I2S0, &I2S1};
+#else
+static i2s_dev_t* I2S[I2S_NUM_MAX] = {&I2S0};	
+#endif
 
 callback shiftCompleteCallback;
 void setShiftCompleteCallback(callback f) {
     shiftCompleteCallback = f;
 }
 
-volatile bool previousBufferFree = true;
+volatile int  previousBufferOutputLoopCount = 0;
+volatile bool previousBufferFree      = true;
 
 static void IRAM_ATTR irq_hndlr(void* arg) { // if we use I2S1 (default)
 
-#ifdef ESP_ORIG
+#ifdef ESP32_ORIG
 
     if ( (*(i2s_port_t*)arg) == I2S_NUM_1 ) { // https://www.bogotobogo.com/cplusplus/pointers2_voidpointers_arrays.php
       //For I2S1
@@ -51,17 +58,25 @@ static void IRAM_ATTR irq_hndlr(void* arg) { // if we use I2S1 (default)
     }
 
 #else
-	  // Other ESP32 MCU's only have one I2S 
+      // Other ESP32 MCU's only have one I2S 
       SET_PERI_REG_BITS(I2S_INT_CLR_REG(0), I2S_OUT_EOF_INT_CLR_V, 1, I2S_OUT_EOF_INT_CLR_S);    
 
-#endif	
-
-    // at this point, the previously active buffer is free, go ahead and write to it
-    previousBufferFree = true;
-
-    if(shiftCompleteCallback) // we've defined a callback function ?
-        shiftCompleteCallback();
-		
+#endif
+/*
+    if ( previousBufferOutputLoopCount == 1)
+	{
+		// at this point, the previously active buffer is free, go ahead and write to it
+		previousBufferFree 		= true;
+		////previousBufferOutputLoopCount = 0;
+		//i2s_parallel_set_previous_buffer_not_free();
+	}
+	else { previousBufferOutputLoopCount++; } 
+*/
+	previousBufferFree 		= true;
+	
+ //   if(shiftCompleteCallback) // we've defined a callback function ?
+ //       shiftCompleteCallback();
+        
 } // end irq_hndlr
 
 
@@ -155,7 +170,7 @@ void link_dma_desc(volatile lldesc_t *dmadesc, volatile lldesc_t *prevdmadesc, v
 
 esp_err_t i2s_parallel_driver_install(i2s_port_t port, i2s_parallel_config_t* conf) {
   
-  port = I2S_NUM_0; /// override.
+  //port = I2S_NUM_0; /// override.
   
   if(port < I2S_NUM_0 || port >= I2S_NUM_MAX) {
     return ESP_ERR_INVALID_ARG;
@@ -176,7 +191,7 @@ esp_err_t i2s_parallel_driver_install(i2s_port_t port, i2s_parallel_config_t* co
   int irq_source;
   
   // Initialize I2S0 peripheral
-  //if (port == I2S_NUM_0) {
+  if (port == I2S_NUM_0) {
       periph_module_reset(PERIPH_I2S0_MODULE);
       periph_module_enable(PERIPH_I2S0_MODULE);
       iomux_clock = I2S0O_WS_OUT_IDX;
@@ -193,8 +208,12 @@ esp_err_t i2s_parallel_driver_install(i2s_port_t port, i2s_parallel_config_t* co
         case I2S_PARALLEL_WIDTH_MAX:
           return ESP_ERR_INVALID_ARG;
       }
-  /*
-  } else {
+  } 
+#ifdef ESP32_ORIG    
+  // Can't compile if I2S1 if it doesn't exist with that hardware's IDF.... 
+  else {
+//	  I2S = &I2S1;
+	  
       periph_module_reset(PERIPH_I2S1_MODULE);
       periph_module_enable(PERIPH_I2S1_MODULE);
       iomux_clock = I2S1O_WS_OUT_IDX;
@@ -212,12 +231,14 @@ esp_err_t i2s_parallel_driver_install(i2s_port_t port, i2s_parallel_config_t* co
           return ESP_ERR_INVALID_ARG;
       }
   }
-  */
+#endif 
+
   // Setup GPIOs
   int bus_width = get_bus_width(conf->sample_width);
 
   // Setup I2S peripheral
-  i2s_dev_t* dev = I2S;
+  i2s_dev_t* dev =  I2S[port];
+  //dev_reset(dev);    
   
   
   // Setup GPIO's
@@ -245,7 +266,7 @@ esp_err_t i2s_parallel_driver_install(i2s_port_t port, i2s_parallel_config_t* co
   
 #ifdef ESP32_SXXX
   dev->clkm_conf.clk_sel = 2; // esp32-s2 only  
-  dev->clkm_conf.clk_en	 = 1;
+  dev->clkm_conf.clk_en  = 1;
 #endif
 
 #ifdef ESP32_ORIG
@@ -314,7 +335,7 @@ esp_err_t i2s_parallel_driver_install(i2s_port_t port, i2s_parallel_config_t* co
 
   
   // Device Reset
-  dev_reset(dev);  
+  dev_reset(dev);    
   dev->conf1.val = 0;
   dev->conf1.tx_stop_en = 0; 
   
@@ -329,25 +350,27 @@ esp_err_t i2s_parallel_driver_install(i2s_port_t port, i2s_parallel_config_t* co
   state->dmadesc_b      = conf->lldesc_b;  
   state->i2s_interrupt_port_arg  = port; // need to keep this somewhere in static memory for the ISR
 
-  // Get ISR setup 
-  esp_err_t err =  esp_intr_alloc(irq_source, 
-                                 (int)(ESP_INTR_FLAG_IRAM | ESP_INTR_FLAG_LEVEL1),
-                                 irq_hndlr, 
-                                 &state->i2s_interrupt_port_arg, NULL);
-  
-  if(err) {
-      return err;
-  }
-
-   
   dev->timing.val = 0;
-  
-  
-  // Setup interrupt handler which is focussed only on the (page 322 of Tech. Ref. Manual)
-  // "I2S_OUT_EOF_INT: Triggered when rxlink has finished sending a packet"
-  // ... whatever the hell that is supposed to mean... One massive linked list.
-  dev->int_ena.out_eof = 1;
 
+  // We using the double buffering switch logic?
+  if (conf->int_ena_out_eof)
+  {
+      // Get ISR setup 
+      esp_err_t err =  esp_intr_alloc(irq_source, 
+                                     (int)(ESP_INTR_FLAG_IRAM | ESP_INTR_FLAG_LEVEL1),
+                                     irq_hndlr, 
+                                     &state->i2s_interrupt_port_arg, NULL);
+      
+      if(err) {
+          return err;
+      }
+
+      
+      // Setup interrupt handler which is focussed only on the (page 322 of Tech. Ref. Manual)
+      // "I2S_OUT_EOF_INT: Triggered when rxlink has finished sending a packet"
+      // ... whatever the hell that is supposed to mean... One massive linked list? So all pixels in the chain?
+      dev->int_ena.out_eof = 1;
+  }
    
   return ESP_OK;
 }
@@ -357,7 +380,7 @@ esp_err_t i2s_parallel_driver_install(i2s_port_t port, i2s_parallel_config_t* co
     return ESP_ERR_INVALID_ARG;
   }
 
-  i2s_dev_t* dev = I2S;
+  i2s_dev_t* dev =  I2S[port];
   
   // Stop all ongoing DMA operations
   dev->out_link.stop = 1;
@@ -373,7 +396,7 @@ esp_err_t i2s_parallel_driver_install(i2s_port_t port, i2s_parallel_config_t* co
     return ESP_ERR_INVALID_ARG;
   }
 
-  i2s_dev_t* dev = I2S;
+  i2s_dev_t* dev =  I2S[port];
   
 
   // Configure DMA burst mode
@@ -390,16 +413,23 @@ esp_err_t i2s_parallel_driver_install(i2s_port_t port, i2s_parallel_config_t* co
 
   return ESP_OK;
 }
-
+/*
 i2s_dev_t* i2s_parallel_get_dev(i2s_port_t port) {
   if(port < I2S_NUM_0 || port >= I2S_NUM_MAX) {
     return NULL;
   }
-  return I2S; // HARCODE THIS TO RETURN &I2S0
-}
 
+#ifdef ESP32_ORIG
+if (port == I2S_NUM_1)
+	return &I2S1;
+#endif  
+  
+  return I2S0; // HARCODE THIS TO RETURN &I2S0
+}
+*/
 // Double buffering flipping
 // Flip to a buffer: 0 for bufa, 1 for bufb
+// dmadesc_a and dmadesc_b point to the same memory if double buffering isn't enabled.
 void i2s_parallel_flip_to_buffer(i2s_port_t port, int buffer_id) {
 
     if (i2s_state == NULL) {
@@ -418,9 +448,16 @@ void i2s_parallel_flip_to_buffer(i2s_port_t port, int buffer_id) {
     i2s_state->dmadesc_b[i2s_state->desccount_b-1].qe.stqe_next = active_dma_chain;
 
     // we're still shifting out the buffer, so it shouldn't be written to yet.
-    previousBufferFree = false;
+    //previousBufferFree = false;
+	i2s_parallel_set_previous_buffer_not_free();
 }
 
 bool i2s_parallel_is_previous_buffer_free() {
     return previousBufferFree;
 }
+
+
+void i2s_parallel_set_previous_buffer_not_free() {
+    previousBufferFree = false;
+	previousBufferOutputLoopCount = 0;
+}
diff --git a/esp32_i2s_parallel_dma.h b/esp32_i2s_parallel_dma.h
index 2b16e24..1570fe2 100644
--- a/esp32_i2s_parallel_dma.h
+++ b/esp32_i2s_parallel_dma.h
@@ -41,6 +41,7 @@ typedef struct {
     int desccount_b;      // only used with double buffering
     lldesc_t * lldesc_b;  // only used with double buffering
     bool clkphase;        // Clock signal phase
+	bool int_ena_out_eof; // Do we raise an interrupt every time the DMA output loops? Don't do this unless we're doing double buffering!
 } i2s_parallel_config_t;
 
 static inline int i2s_parallel_get_memory_width(i2s_port_t port, i2s_parallel_cfg_bits_t width) {
@@ -72,7 +73,7 @@ void link_dma_desc(volatile lldesc_t *dmadesc, volatile lldesc_t *prevdmadesc, v
 esp_err_t 	i2s_parallel_driver_install(i2s_port_t port, i2s_parallel_config_t* conf);
 esp_err_t 	i2s_parallel_send_dma(i2s_port_t port, lldesc_t* dma_descriptor);
 esp_err_t 	i2s_parallel_stop_dma(i2s_port_t port);
-i2s_dev_t* 	i2s_parallel_get_dev(i2s_port_t port);
+//i2s_dev_t* 	i2s_parallel_get_dev(i2s_port_t port);
 
 // For frame buffer flipping / double buffering
 typedef struct {
@@ -83,6 +84,7 @@ typedef struct {
 
 void i2s_parallel_flip_to_buffer(i2s_port_t port, int bufid);
 bool i2s_parallel_is_previous_buffer_free();
+void i2s_parallel_set_previous_buffer_not_free();
 
 // Callback function for when whole length of DMA chain has been sent out.
 typedef void (*callback)(void);
diff --git a/examples/1_SimpleTestShapes/1_SimpleTestShapes.ino b/examples/1_SimpleTestShapes/1_SimpleTestShapes.ino
index cfcd768..db3b0d1 100644
--- a/examples/1_SimpleTestShapes/1_SimpleTestShapes.ino
+++ b/examples/1_SimpleTestShapes/1_SimpleTestShapes.ino
@@ -143,11 +143,11 @@ uint8_t wheelval = 0;
 void loop() {
 
     // animate by going through the colour wheel for the first two lines
-    //drawText(wheelval);
-    //wheelval +=1;
-
-    //delay(20); 
+    drawText(wheelval);
+    wheelval +=1;
 
+    delay(20); 
+/*
   drawText(0);
   delay(2000);
   dma_display->clearScreen();
@@ -161,5 +161,6 @@ void loop() {
   delay(2000);
   dma_display->fillScreen(myWHITE);
   dma_display->clearScreen();
+  */
   
 }
diff --git a/examples/README.md b/examples/README.md
index 9144af8..2acbd79 100644
--- a/examples/README.md
+++ b/examples/README.md
@@ -8,7 +8,6 @@
 |BitmapIcons                |Simple example of how to display a bitmap image to the display.                                                        |
 |ChainedPanels              |Popular example on how to use the 'VirtualDisplay' class to chain multiple LED Matrix Panels to form a much bigger display! Refer to the README within this example's folder! |
 |ChainedPanelsAuroraDemo    |As above, but showing a large trippy plasma animation.                                                                 |
-|Smooth Double Buffer       |Example of using a back-buffer (double buffering). Not useful in 99.9% of use-cases of this library. Uses double the SRAM as well.          |
-|One_Quarter_1_4_ScanPanel     |Using this library with a 32w x 16h 1/4 Scan LED Matrix Panel. Custom co-ordinate remapping logic required.                               |
-|One_Eighth_1_8_ScanPanel     |Using this library with a 64w x 32h 1/8 Scan LED Matrix Panel. Custom co-ordinate remapping logic required.
+|One_Quarter_1_4_ScanPanel  |Using this library with a 32w x 16h 1/4 Scan LED Matrix Panel. Custom co-ordinate remapping logic required.                               |
+|One_Eighth_1_8_ScanPanel   |Using this library with a 64w x 32h 1/8 Scan LED Matrix Panel. Custom co-ordinate remapping logic required.
 |PIO_TestPatterns           |Non-Arduino example of how to display basic shapes.                                                                    |