add the option to select any trigger pin.

Author: thomasfla

src/current/rp2350/RP2350PIOCurrentSense.cpp

@@ -1,11 +1,12 @@
     #include "RP2350PIOCurrentSense.h"
 
-    RP2350PIOCurrentSense::RP2350PIOCurrentSense(float gain, uint32_t max_adc_value, int pinSCK, int pinCSB, int pinD0) : CurrentSense() {
+    RP2350PIOCurrentSense::RP2350PIOCurrentSense(float gain, uint32_t max_adc_value, int pinSCK, int pinCSB, int pinD0, int pinTRIG) : CurrentSense() {
         this->pinSCK = pinSCK;
         this->pinCSB = pinCSB;
         this->pinD0 = pinD0;
         this->pinD1 = pinD0+1;
         this->pinD2 = pinD0+2;
+        this->pinTRIG = pinTRIG;
         this->gain_a = gain;
         this->gain_b = gain;
         this->gain_c = gain;
@@ -35,7 +36,16 @@
         int sm = pio_claim_unused_sm(pio0, false);
         if (sm < 0) { pio = pio1; sm = pio_claim_unused_sm(pio1, true); }
 
-        uint off = pio_add_program(pio, &bu79100g_parallel3_program);
+        // --- patch program instructions with chosen trigger pin ---
+        size_t prog_len = bu79100g_parallel3_program.length;
+        uint16_t insns[prog_len];
+        memcpy(insns, bu79100g_parallel3_program_instructions, sizeof(insns));
+        insns[1] = (insns[1] & ~0x1Fu) | (this->pinTRIG & 0x1Fu);
+        insns[2] = (insns[2] & ~0x1Fu) | (this->pinTRIG & 0x1Fu);
+        struct pio_program prog = bu79100g_parallel3_program; // copy metadata
+        prog.instructions = insns;
+    
+        uint off = pio_add_program(pio, &prog);
         pio_sm_config c = bu79100g_parallel3_program_get_default_config(off);
 
         // Map pins to the SM

src/current/rp2350/RP2350PIOCurrentSense.h

@@ -6,7 +6,7 @@
 
 class RP2350PIOCurrentSense: public CurrentSense {
   public:
-    RP2350PIOCurrentSense(float gain, uint32_t max_adc_value, int pinSCK, int pinCSB, int pinD0);
+    RP2350PIOCurrentSense(float gain, uint32_t max_adc_value, int pinSCK, int pinCSB, int pinD0, int pinTRIG);
     ~RP2350PIOCurrentSense();
 
     int init() override;
@@ -19,6 +19,7 @@ class RP2350PIOCurrentSense: public CurrentSense {
     int pinD0;
     int pinD1;
     int pinD2;
+    int pinTRIG;
     int gain_a;
     int gain_b;
     int gain_c;

src/current/rp2350/bu79100g_parallel3.pio

@@ -9,8 +9,8 @@
 .wrap_target
     set pins, 1   side 1   ; CSB=1, SCK=1
     ; -------- wait external falling edge on absolute GPIO ----------
-    wait 1 gpio 11 ; TODO, we will need to have this pin setable from the C code. direcetly edit the program?
-    wait 0 gpio 11
+    wait 1 gpio 11 ;THIS INSTRUCTION WILL BE PATCHED AT RUNTIME TO CHANGE GPIO. DO NOT MOVE IT WITHOUT CHANGING PIO INIT.
+    wait 0 gpio 11 ;THIS INSTRUCTION WILL BE PATCHED AT RUNTIME TO CHANGE GPIO. DO NOT MOVE IT WITHOUT CHANGING PIO INIT.
     set pins, 0   side 1          ; CS=0, SCK=1
     set x, 15     side 1          ; prepare loop cpt
     ; -------- 16 dummy clocks (no sampling) -----------------------