Trying some faster-bitplanes stuff, not quite right, may need to use different periph.

src/arch/esp32-common.h

@@ -20,6 +20,8 @@
 #if defined(ESP32) ||                                                          \
     defined(ESP_PLATFORM) // *All* ESP32 variants (OG, S2, S3, etc.)
 
+extern volatile uint8_t bitz;
+
 #include "esp_idf_version.h"
 
 // NOTE: there is some intentional repetition in the macros and functions
@@ -58,6 +60,7 @@ static hw_timer_t *_PM_esp32timer = NULL;
 #define _PM_TIMER_DEFAULT &_PM_esp32timer
 
 extern IRAM_ATTR void _PM_row_handler(Protomatter_core *core); // In core.c
+extern IRAM_ATTR void _PM_OE_off(Protomatter_core *core);
 
 // Timer interrupt handler. This, _PM_row_handler() and any functions
 // called by _PM_row_handler() should all have the IRAM_ATTR attribute
@@ -65,7 +68,13 @@ extern IRAM_ATTR void _PM_row_handler(Protomatter_core *core); // In core.c
 // callback invoked by the real ISR (in arduino-esp32's esp32-hal-timer.c)
 // which takes care of interrupt status bits & such.
 IRAM_ATTR static void _PM_esp32timerCallback(void) {
-  _PM_row_handler(_PM_protoPtr); // In core.c
+  bitz |= 2;
+  if (bitz == 3) {
+    _PM_row_handler(_PM_protoPtr); // In core.c
+  } else {
+    _PM_OE_off(_PM_protoPtr);
+    _PM_timerStop(_PM_protoPtr);
+  }
 }
 
 // Set timer period, initialize count value to zero, enable timer.

src/arch/esp32-s3.h

@@ -79,7 +79,8 @@ IRAM_ATTR inline uint32_t _PM_timerGetCount(Protomatter_core *core) {
 // slightly different length of time, but duty cycle scales with this so it's
 // perceptually consistent; don't see bright or dark rows.
 
-#define _PM_minMinPeriod (200 + (uint32_t)core->chainBits * 2)
+//#define _PM_minMinPeriod (200 + (uint32_t)core->chainBits * 2)
+#define _PM_minMinPeriod 40
 
 #if (ESP_IDF_VERSION_MAJOR == 5)
 #include <esp_private/periph_ctrl.h>
@@ -129,6 +130,7 @@ static void pinmux(int8_t pin, uint8_t signal) {
 }
 
 #if defined(ARDUINO) // COMPILING FOR ARDUINO ------------------------------
+
 // LCD_CAM requires a complete replacement of the "blast" functions in order
 // to use the DMA-based peripheral.
 #define _PM_CUSTOM_BLAST // Disable blast_*() functions in core.c
@@ -160,6 +162,19 @@ IRAM_ATTR static void blast_byte(Protomatter_core *core, uint8_t *data) {
   // See notes near top of this file for what's done with this info.
 }
 
+volatile uint32_t bloop = 0;
+extern volatile uint8_t bitz;
+extern IRAM_ATTR void _PM_OE_off(Protomatter_core *core);
+
+IRAM_ATTR static bool dma_callback(gdma_channel_handle_t dma_chan,
+  gdma_event_data_t *event_data, void *user_data) {
+  bitz |= 1; // DMA xfer has finished
+  if (bitz == 3)
+    _PM_row_handler(_PM_protoPtr); // In core.c
+  bloop++;
+  return true;
+}
+
 void _PM_timerInit(Protomatter_core *core) {
   // On S3, initialize the LCD_CAM peripheral and DMA.
 
@@ -247,9 +262,11 @@ void _PM_timerInit(Protomatter_core *core) {
   gdma_set_transfer_ability(dma_chan, &ability);
   gdma_start(dma_chan, (intptr_t)&desc);
 
-  // Enable TRANS_DONE interrupt. Note that we do NOT require nor install
-  // an interrupt service routine, but DO need to enable the TRANS_DONE
-  // flag to make the LCD DMA transfer work.
+  // Enable DMA transfer callback
+  gdma_tx_event_callbacks_t tx_cbs = {
+    .on_trans_eof = dma_callback
+  };  
+  gdma_register_tx_event_callbacks(dma_chan, &tx_cbs, NULL);
   LCD_CAM.lc_dma_int_ena.val |= LCD_LL_EVENT_TRANS_DONE & 0x03;
 
   _PM_esp32commonTimerInit(core); // In esp32-common.h

src/core.c

@@ -341,6 +341,7 @@ ProtomatterStatus _PM_begin(Protomatter_core *core) {
   uint32_t minPeriodPerFrame = _PM_timerFreq / _PM_MAX_REFRESH_HZ;
   uint32_t minPeriodPerLine = minPeriodPerFrame / core->numRowPairs;
   core->minPeriod = minPeriodPerLine / ((1 << core->numPlanes) - 1);
+core->minPeriod = _PM_minMinPeriod;
   if (core->minPeriod < _PM_minMinPeriod) {
     core->minPeriod = _PM_minMinPeriod;
   }
@@ -487,6 +488,13 @@ void _PM_deallocate(Protomatter_core *core) {
   }
 }
 
+volatile uint8_t bitz = 3;
+
+IRAM_ATTR void _PM_OE_off(Protomatter_core *core) {
+  _PM_clearReg(core->oe);
+  _PM_setReg(core->oe); // Disable LED output
+}
+
 // ISR function (in arch.h) calls this function which it extern'd.
 // Profuse apologies for the ESP32-specific IRAM_ATTR here -- the goal was
 // for all architecture-specific detauls to be in arch.h -- but the need
@@ -497,6 +505,7 @@ void _PM_deallocate(Protomatter_core *core) {
 // specific section of arch.h. Sorry. :/
 // Any functions called by this function should also be IRAM_ATTR'd.
 IRAM_ATTR void _PM_row_handler(Protomatter_core *core) {
+  bitz = 0;
 
   _PM_setReg(core->oe); // Disable LED output
 
@@ -577,7 +586,7 @@ IRAM_ATTR void _PM_row_handler(Protomatter_core *core) {
 
   // Set timer and enable LED output for data loaded on PRIOR pass:
   _PM_timerStart(core, core->bitZeroPeriod << prevPlane);
-  _PM_delayMicroseconds(1); // Appease Teensy4
+//  _PM_delayMicroseconds(1); // Appease Teensy4
   _PM_clearReg(core->oe);   // Enable LED output
 
   uint32_t elementsPerLine =
@@ -610,7 +619,7 @@ IRAM_ATTR void _PM_row_handler(Protomatter_core *core) {
     // Timer is still running and counting up at this point.
     uint32_t elapsed = _PM_timerGetCount(core);
     // Nudge the plane-zero time up or down (filtering to avoid jitter)
-    core->bitZeroPeriod = ((core->bitZeroPeriod * 7) + elapsed + 4) / 8;
+//    core->bitZeroPeriod = ((core->bitZeroPeriod * 7) + elapsed + 4) / 8;
     // But don't allow it to drop below the minimum period calculated during
     // begin(), that's a hard limit and would just waste cycles.
     if (core->bitZeroPeriod < core->minPeriod) {