Fix bit order, edge sampling and deinterleaving, First working version, validated on RP2350 with 3 ADCs

Author: thomasfla

src/current/rp2350/RP2350PIOCurrentSense.cpp

@@ -64,7 +64,7 @@
         pio_sm_set_consecutive_pindirs(pio, sm, this->pinD0,  3, false);  // D0..D2 in
 
         // Shift config: right, autopush every 32 bits (two pushes per conversion)
-        sm_config_set_in_shift(&c, true, true, 32);
+        sm_config_set_in_shift(&c, false, true, 32);
 
         // SCK ≈ clk_sys / (2 * clkdiv) because each SCK period = 2 instructions
         float div = (float)clock_get_hz(clk_sys) / (2.0f * sck_hz);
@@ -121,7 +121,7 @@
         *c = 0;
         *d = 0;
         for (int i = 0; i < 64; i += 4) {
-            uint32_t w = (i < 32) ? w1 : w0;
+            uint32_t w = (i < 32) ? w0 : w1;
             int shift = 28 - (i % 32);  // 28, 24, ..., 0 for each group of 4 bits
 
             uint32_t group = (w >> shift) & 0xF;  // extract aN bN cN dN

src/current/rp2350/bu79100g_parallel3.pio

@@ -17,13 +17,12 @@ dummy_loop:
         nop           side 0          ; SCK=0
         jmp x--, dummy_loop side 1    ; SCK=1
     set pins, 1   side 1       ; CSB=0, keep SCK=HIGH at CSB falling (datasheet rec.)
-    set x, 15     side 1
+    set x, 15     side 1  
     set pins, 0
-    ; -------- 16 real clocks, sample on SCK rising edge -----------
+    ; -------- 16 real clocks, sample on SCK falling edge -----------
 read_loop:    
-        ;nop          side 1  ;DEBUG so we don't have to wait for autopush.
-        in  pins, 4   side 1          ; SCK=1, sample D2..D0 on rising edge  ;Note, Here I had to read 4 pins instead of 3. It seems that with 3, a bit is lost after the first push. Need to read the doc again
-        jmp x--, read_loop side 0      ; SCK=0
+        in  pins, 4   side 0          ; SCK=0, sample D2..D0 on falling edge  ;Note, Here I had to read 4 pins instead of 3. It seems that with 3, a bit is lost after the first push. Need to read the doc again
+        jmp x--, read_loop side 1      ; SCK=1
     ; -------- finish conversion -----------------------------------
     set pins, 1   side 1               ; CSB=1, SCK=1
     ; -------- Pad with 0 ------------------------------------------

src/current/rp2350/bu79100g_parallel3.pio.h

@@ -13,7 +13,7 @@
 // ------------------ //
 
 #define bu79100g_parallel3_wrap_target 0
-#define bu79100g_parallel3_wrap 14
+#define bu79100g_parallel3_wrap 12
 #define bu79100g_parallel3_pio_version 1
 
 static const uint16_t bu79100g_parallel3_program_instructions[] = {
@@ -28,18 +28,16 @@ static const uint16_t bu79100g_parallel3_program_instructions[] = {
     0xf801, //  7: set    pins, 1         side 1
     0xf82f, //  8: set    x, 15           side 1
     0xe000, //  9: set    pins, 0
-    0x5804, // 10: in     pins, 4         side 1
-    0x104a, // 11: jmp    x--, 10         side 0
+    0x5004, // 10: in     pins, 4         side 0
+    0x184a, // 11: jmp    x--, 10         side 1
     0xf801, // 12: set    pins, 1         side 1
-    0xe020, // 13: set    x, 0
-    0xa029, // 14: mov    x, ~x
             //     .wrap
 };
 
 #if !PICO_NO_HARDWARE
 static const struct pio_program bu79100g_parallel3_program = {
     .instructions = bu79100g_parallel3_program_instructions,
-    .length = 15,
+    .length = 13,
     .origin = -1,
     .pio_version = bu79100g_parallel3_pio_version,
 #if PICO_PIO_VERSION > 0