Handle LSB and MSB rows

Author: mkalkbrenner

src/dmd_interface_whitestar.pio

@@ -10,10 +10,10 @@
 
 ; Send using an external clock on the SPI interface
 
-    ; initialize y with 4096 = number of pixels (128x32)
+    ; initialize y with 8192 = number of pixels ((128 x LSB + 128 x MSB) x 32)
     set x, 1
     in x, 1
-    in null, 13
+    in null, 14
     mov y, isr
 
 .wrap_target
@@ -24,39 +24,27 @@
     irq clear 4
     wait irq 4
 
+    wait 1 gpio RDATA   ; raising edge indicates a new frame
 
-; this is the loop for the most significant bit
-dotloop1:
+dotloop:
     wait 0 gpio DOTCLK  ; falling edge
+    in null 1           ; left padding
     wait 1 gpio DOTCLK  ; raising edge
     in pins 1           ; read pin data
-    in null 1           ; right padding
-    jmp x-- dotloop1
+    jmp x-- dotloop
 
     mov x, y            ; load number of pixels
     mov isr, null       ; reset shift counter
 
-; There's an empty line between LSB and HSB plane
-    wait 0 gpio RCLK
-    wait 1 gpio RCLK
-
-; this is the loop for the least significant bit
-; in this loop, the bit value is multipled by 2 by shiting it one bit
-dotloop2:
-    wait 0 gpio DOTCLK  ; falling edge
-    in null 1           ; left padding
-    wait 1 gpio DOTCLK  ; raising edge
-    in pins 1           ; read pin data
-    jmp x-- dotloop2
-
-
+; There's an empty row with 256 gots at the end of a frame.
+; it is ignored because we already read the specified amount of dots and now wait for a new frame.
 .wrap
 
 .program dmd_framedetect_whitestar
 
 .wrap_target
 
-; synchronize on the least significant plane
+; synchronize on a new frame
     wait 0 gpio RDATA
     wait 1 gpio RDATA
     irq 4
@@ -109,4 +97,4 @@ static inline void dmd_framedetect_whitestar_program_init(PIO pio, uint sm, uint
     // Load our configuration, do not yet start the program
     pio_sm_init(pio, sm, offset, &c);
 }
-%}
+%}

src/dmd_reader.c

@@ -102,6 +102,7 @@ typedef struct __attribute__((__packed__)) block_pix_crc_header_t
 #define LINEOVERSAMPLING_4X 4
 
 // Merging multiple planes
+#define MERGEPLANES_NONE 0
 #define MERGEPLANES_ADD 0
 #define MERGEPLANES_ADDSHIFT 1
 
@@ -495,7 +496,7 @@ void dmd_dma_handler() {
 
         for (int l=0; l<lcd_height; l++) {
             for (int w=0; w<lcd_wordsperline; w++) {
-                v = (src1[w] + src2[w]) >> 1;
+                v = src1[w] + src2[w]*2;
                 dst[w]=v;
             }
             src1 += lcd_wordsperline*2; // source skips 2 lines forward
@@ -597,9 +598,9 @@ bool init()
         lcd_height = 32;
         lcd_bitsperpixel = 2;                                    // Whitestar is 2bpp
         lcd_pixelsperbyte = 8 / lcd_bitsperpixel;
-        lcd_planesperframe = 2;                                  // in Whitestar, there's a MSB and a LSB plane
+        lcd_planesperframe = 1;                                  // in Whitestar, there's only one plane, containg one LSB row followed by one MSB row and so on
         lcd_lineoversampling = LINEOVERSAMPLING_2X;       // in Whitestar each line is sent twice
-        lcd_mergeplanes = MERGEPLANES_ADD;                  // Shifting happen in pio code
+        lcd_mergeplanes = MERGEPLANES_NONE;
     } else if (dmd_type == DMD_SPIKE1)  {
         dmd_pio = pio0;
         offset = pio_add_program(dmd_pio, &dmd_reader_spike_program);