Convert TB6600 timing setup to initTiming() pattern from #140

Replace the TB6600_SET_TIMING() macro in the .cpp with a protected
inline initTiming() method in the header, matching the pattern the
other drivers adopted in PR #140.

Agent: claude-fable-5 (Claude Code 2.1.212)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: laurb9

src/TB6600.cpp

@@ -9,20 +9,17 @@
  */
 #include "TB6600.h"
 
-// TB6600 datasheet timing: min PUL clock HIGH/LOW 2.2us -> 3, wakeup 10us
-#define TB6600_SET_TIMING() do { step_high_min = 3; step_low_min = 3; wakeup_time = 10; } while (0)
-
 /*
  * Basic connection: only DIR, STEP (PUL) are connected.
  * Microstepping is configured via the board's DIP switches.
  */
 TB6600::TB6600(short steps, short dir_pin, short step_pin)
 :BasicStepperDriver(steps, dir_pin, step_pin)
-{ TB6600_SET_TIMING(); }
+{ initTiming(); }
 
 TB6600::TB6600(short steps, short dir_pin, short step_pin, short enable_pin)
 :BasicStepperDriver(steps, dir_pin, step_pin, enable_pin)
-{ TB6600_SET_TIMING(); }
+{ initTiming(); }
 
 short TB6600::getMaxMicrostep(){
     return TB6600::MAX_MICROSTEP;

src/TB6600.h

@@ -22,8 +22,15 @@
 
 class TB6600 : public BasicStepperDriver {
 protected:
-    // Timing (set in constructors): min clock (PUL) HIGH/LOW 2.2us -> 3,
-    // wakeup time after ENA released 10us.
+    // Set timing requirements from TB6600 datasheet
+    void initTiming(){
+        // min clock (PUL) HIGH pulse duration (2.2us -> 3)
+        step_high_min = 3;
+        // min clock (PUL) LOW pulse duration (2.2us -> 3)
+        step_low_min = 3;
+        // wakeup time after ENA released (10us)
+        wakeup_time = 10;
+    }
 
     // Get max microsteps supported by the device (TB6600HG up to 1:16)
     short getMaxMicrostep() override;