Eliminated MachineCommon.h

It had only a few consts that were either unnecessary or module
specific.  I eliminated the former and moved the latter.

Grbl_Esp32/src/Config.h

@@ -48,13 +48,6 @@ Some features should not be changed. See notes below.
 
 const int SUPPORT_TASK_CORE = 1;  // Reference: CONFIG_ARDUINO_RUNNING_CORE = 1
 
-// Include the file that loads the machine-specific config file.
-// machine.h must be edited to choose the desired file.
-#include "Machine.h"
-
-// machine_common.h contains settings that do not change
-#include "MachineCommon.h"
-
 const int MAX_N_AXIS = 6;
 
 // Serial baud rate

Grbl_Esp32/src/Limits.cpp

@@ -254,8 +254,8 @@ void limits_go_home(uint8_t cycle_mask, uint32_t n_locate_cycles) {
                     break;
                 }
             }
-        } while (STEP_MASK & axislock);
 
+        } while (axislock);
         if (config->_stepType == ST_I2S_STREAM) {
             if (!approach) {
                 delay_ms(I2S_OUT_DELAY_MS);

Grbl_Esp32/src/MachineCommon.h

@@ -1,15 +0,0 @@
-#pragma once
-
-// Grbl setting that are common to all machines
-// It should not be necessary to change anything herein
-
-const int32_t GRBL_SPI_FREQ = 4000000;
-
-    // ESP32 CPU Settings
-const uint32_t fTimers = 80000000;  // a reference to the speed of ESP32 timers
-
-// =============== Don't change or comment these out ======================
-// They are for legacy purposes and will not affect your I/O
-
-const int STEP_MASK  = 0x3F;  // 111111
-const int PROBE_MASK = 1;

Grbl_Esp32/src/SDCard.cpp

@@ -163,9 +163,8 @@ SDCard::State SDCard::get_state(bool refresh) {
 
         _state = SDCard::State::NotPresent;
 
-        //using default value for speed ? should be parameter
         //refresh content if card was removed
-        if (SD.begin(csPin, SPI, GRBL_SPI_FREQ, "/sd", 2)) {
+        if (SD.begin(csPin, SPI, SPIfreq, "/sd", 2)) {
             if (SD.cardSize() > 0) {
                 _state = SDCard::State::Idle;
             }

Grbl_Esp32/src/SDCard.h

@@ -26,6 +26,9 @@ namespace fs {
     class FS;
 }
 
+// XXX This should be a configuration parameter of the SPI bus
+const int32_t SPIfreq = 4000000;
+
 class SDCard : public Configuration::Configurable {
 public:
     enum class State : uint8_t {

Grbl_Esp32/src/StepperPrivate.h

@@ -24,6 +24,7 @@ struct PrepFlag {
 };
 
 // fStepperTimer should be an integer divisor of the bus speed, i.e. of fTimers
+const uint32_t fTimers             = 80000000;  // the frequency of ESP32 timers
 const uint32_t fStepperTimer       = 20000000;  // frequency of step pulse timer
 const int      ticksPerMicrosecond = fStepperTimer / 1000000;