- Fixed initialization bug in trinamic drivers

- Added better error handling for validation of pin changes

Grbl_Esp32/src/Motors/TrinamicDriver.cpp

@@ -202,6 +202,14 @@ namespace Motors {
 */
 
     void TrinamicDriver::read_settings() {
+        // When 'test' is called and no actual trinamic is there, _has_errors will evaluate to 'true'. The 
+        // result of that is that the check below will fail. And the result of that is that the step/dir pin 
+        // is not initialized if we don't do it here. Unstep actually uses that pin -- and then you will get 
+        // an assertion for using a pin that's not initialized.
+        //
+        // So... I moved init_step_dir_pins here, which basically solves that.
+        init_step_dir_pins();
+     
         if (_has_errors) {
             return;
         }
@@ -218,8 +226,6 @@ namespace Motors {
         }
         tmcstepper->microsteps(axis_settings[_axis_index]->microsteps->get());
         tmcstepper->rms_current(run_i_ma, hold_i_percent);
-
-        init_step_dir_pins();
     }
 
     bool TrinamicDriver::set_homing_mode(bool isHoming) {

Grbl_Esp32/src/Pin.cpp

@@ -165,7 +165,17 @@ Pin Pin::create(const String& str) {
 bool Pin::validate(const String& str) {
     Pins::PinDetail* pinImplementation;
 
-    auto valid = parse(str, pinImplementation);
+    bool valid = false;
+    try {
+        valid = parse(str, pinImplementation);
+    } catch (const AssertionFailed& e) {
+        // If an assertion happens, it's definitely invalid.
+#ifdef ESP32
+        grbl_msg_sendf(CLIENT_ALL, MsgLevel::Warning, "Validation for pin spec %s failed: %s", str.c_str(), e.error.c_str());
+#endif
+        valid = false;
+    }
+
     if (pinImplementation) {
         delete pinImplementation;
     }

Grbl_Esp32/src/StackTrace/AssertionFailed.cpp

@@ -23,7 +23,7 @@ AssertionFailed AssertionFailed::create(const char* condition, const char* msg,
     st += " at: ";
     st += esp_backtrace_print(10);
 
-    return AssertionFailed(st);
+    return AssertionFailed(st, tmp);
 }
 
 #else

Grbl_Esp32/src/StackTrace/AssertionFailed.h

@@ -6,11 +6,12 @@
 class AssertionFailed {
 public:
     String stackTrace;
+    String error;
 
-    AssertionFailed(String st) : stackTrace(st) {}
+    AssertionFailed(String st, String err) : stackTrace(st), error(err) {}
 
     static AssertionFailed create(const char* condition) {
-        return create(condition, "Assertion failed");
+        return create(condition, "Unknown error (assertion failed).");
     }
     static AssertionFailed create(const char* condition, const char* msg, ...);
 
@@ -24,7 +25,7 @@ public:
     String stackTrace;
 
     static std::exception create(const char* condition) {
-        return create(condition, "Assertion failed");
+        return create(condition, "Unknown error (assertion failed).");
     }
     static std::exception create(const char* condition, const char* msg, ...);
 };