Some updates.

api_drivers/common_api_drivers/display/nv3041a/nv3041a.py

@@ -199,7 +199,8 @@ def _flush_cb(self, _, area, color_p):
 
         data_view = color_p.__dereference__(size)
 
-        first_chunk = int(size / 10)
+        # Divide buffer in 2 chunks:
+        first_chunk = int(size / 2)
 
         self._data_bus.tx_color(self.__ramwr, data_view[:first_chunk], x1, y1, x2, y2, self._rotation, False)
         self._data_bus.tx_color(self.__ramwrc, data_view[first_chunk:], x1, y1, x2, y2, self._rotation, self._disp_drv.flush_is_last())

ext_mod/lcd_bus/esp32_include/rgb565_dither.h

@@ -0,0 +1,19 @@
+#ifndef __RGB565_DITHER_H__
+    #define __RGB565_DITHER_H__
+
+    #define CALC_THRESHOLD(x, y)  (uint8_t)((y & 7) << 3) + (x & 7);
+
+    extern uint8_t *red_thresh;
+    extern uint8_t *green_thresh;
+    extern uint8_t *blue_thresh;
+
+    bool rgb565_dither_init(void);
+
+    static inline rgb565_dither_pixel(uint8_t treshold_id, uint16_t *pixel)
+    {
+        *pixel = (((((pixel >> 8) & 0xF8) + red_thresh[treshold_id]) << 8) |
+                  ((((pixel >> 3) & 0xFC) + green_thresh[treshold_id]) << 3) |
+                  ((((pixel & 0x1F) << 3) + blue_thresh[treshold_id]) >> 3)) ;
+    }
+
+#endif

ext_mod/lcd_bus/esp32_include/rgb_bus.h

@@ -104,6 +104,7 @@
             uint8_t rotation: 2;
             uint8_t bytes_per_pixel: 2;
             uint8_t last_update: 1;
+            uint8_t rgb565_dither: 1;
 
             rgb_bus_lock_t copy_lock;
             rgb_bus_event_t copy_task_exit;

ext_mod/lcd_bus/esp32_src/rgb565_dither.c

@@ -0,0 +1,63 @@
+
+#include "rgb565_dither.h"
+#include <string.h>
+
+
+bool rgb565_dither_init(void)
+{
+    if (red_thresh == NULL) {
+        red_thresh = (uint8_t *)malloc(64);
+        if (red_thresh != NULL) {
+            memcpy(red_thresh,
+                (uint8_t []){
+                1, 7, 3, 5, 0, 8, 2, 6,
+                7, 1, 5, 3, 8, 0, 6, 2,
+                3, 5, 0, 8, 2, 6, 1, 7,
+                5, 3, 8, 0, 6, 2, 7, 1,
+                0, 8, 2, 6, 1, 7, 3, 5,
+                8, 0, 6, 2, 7, 1, 5, 3,
+                2, 6, 1, 7, 3, 5, 0, 8,
+                6, 2, 7, 1, 5, 3, 8, 0
+            }, 64);
+        }
+    }
+
+    if (green_thresh == NULL) {
+        green_thresh = (uint8_t *)malloc(64);
+        if (green_thresh != NULL) {
+            memcpy(green_thresh,
+                (uint8_t []){
+                1, 3, 2, 2, 3, 1, 2, 2,
+                2, 2, 0, 4, 2, 2, 4, 0,
+                3, 1, 2, 2, 1, 3, 2, 2,
+                2, 2, 4, 0, 2, 2, 0, 4,
+                1, 3, 2, 2, 3, 1, 2, 2,
+                2, 2, 0, 4, 2, 2, 4, 0,
+                3, 1, 2, 2, 1, 3, 2, 2,
+                2, 2, 4, 0, 2, 2, 0, 4
+            }, 64);
+        }
+    }
+    if (blue_thresh == NULL) {
+        blue_thresh = (uint8_t *)malloc(64);
+        if (blue_thresh != NULL) {
+            memcpy(blue_thresh,
+                (uint8_t []){
+                5, 3, 8, 0, 6, 2, 7, 1,
+                3, 5, 0, 8, 2, 6, 1, 7,
+                8, 0, 6, 2, 7, 1, 5, 3,
+                0, 8, 2, 6, 1, 7, 3, 5,
+                6, 2, 7, 1, 5, 3, 8, 0,
+                2, 6, 1, 7, 3, 5, 0, 8,
+                7, 1, 5, 3, 8, 0, 6, 2,
+                1, 7, 3, 5, 0, 8, 2, 6
+            }, 64);
+        }
+    }
+
+    if (red_thresh == NULL || blue_thresh == NULL || green_thresh == NULL) return false;
+    else return true;
+}
+
+
+

ext_mod/lcd_bus/esp32_src/rgb_bus.c

@@ -33,6 +33,8 @@
     #include "py/objtype.h"
     #include "py/objexcept.h"
 
+    #include "rgb565_dither.h"
+
     // stdlib includes
     #include <string.h>
 
@@ -101,6 +103,7 @@
             ARG_pclk_idle_high,
             ARG_pclk_active_low,
             ARG_refresh_on_demand,
+            ARG_rgb565_dither
         };
 
         const mp_arg_t allowed_args[] = {
@@ -137,6 +140,7 @@
             { MP_QSTR_pclk_idle_high,     MP_ARG_BOOL | MP_ARG_KW_ONLY, { .u_bool = false  } },
             { MP_QSTR_pclk_active_low,    MP_ARG_BOOL | MP_ARG_KW_ONLY, { .u_bool = false  } },
             { MP_QSTR_refresh_on_demand,  MP_ARG_BOOL | MP_ARG_KW_ONLY, { .u_bool = false  } },
+            { MP_QSTR_rgb565_dither,      MP_ARG_BOOL | MP_ARG_KW_ONLY, { .u_bool = false  } },
         };
 
         mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
@@ -148,6 +152,8 @@
 
         self->callback = mp_const_none;
 
+        self->rgb565_dither = (uint8_t)args[ARG_rgb565_dither].u_bool;
+
         self->bus_config.pclk_hz = (uint32_t)args[ARG_freq].u_int;
         self->bus_config.hsync_pulse_width = (uint32_t)args[ARG_hsync_pulse_width].u_int;
         self->bus_config.hsync_back_porch = (uint32_t)args[ARG_hsync_back_porch].u_int;
@@ -345,6 +351,8 @@
 
         mp_lcd_rgb_bus_obj_t *self = (mp_lcd_rgb_bus_obj_t *)obj;
 
+        if (bpp != 16 && self->rgb565_dither) self->rgb565_dither = 0;
+
         if (bpp == 16 && rgb565_byte_swap) {
             /*
             We change the pins aound when the bus width is 16 and wanting to