esp8266: add an ISR-driven example to protect from WiFi operations

examples/Bounce-ESP8266-ISR/Bounce-ESP8266-ISR.ino

@@ -0,0 +1,48 @@
+// Bounce.pde
+// -*- mode: C++ -*-
+//
+// Make a single stepper bounce from one limit to another
+//
+// Copyright (C) 2012 Mike McCauley
+// $Id: Random.pde,v 1.1 2011/01/05 01:51:01 mikem Exp mikem $
+
+#include <AccelStepper.h>
+
+// Define a stepper and the pins it will use
+#define DIR             12              // esp8266 gpio
+#define STEP            13              // esp8266 gpio
+AccelStepper stepper(AccelStepper::DRIVER, STEP, DIR);
+
+IRAM_ATTR
+void stepperRun ()
+{
+    stepper.run();
+}
+
+void setup()
+{
+  // Change these to suit your stepper if you want
+  stepper.setMaxSpeed(10000);
+  stepper.setAcceleration(10000);
+  stepper.moveTo(500);
+
+  // initialize ISR
+  timer1_isr_init();
+  timer1_enable(TIM_DIV1, TIM_EDGE, TIM_LOOP);
+  timer1_attachInterrupt(stepperRun);
+  timer1_write(microsecondsToClockCycles(100));
+}
+
+void loop()
+{
+    // cli() / sei() barriers are necessary when timer is enabled
+    cli();
+
+    // If at the end of travel go to the other end
+    if (stepper.distanceToGo() == 0)
+      stepper.moveTo(-stepper.currentPosition());
+
+    sei(); // barrier ends
+
+    delay(1000); // ISR does not mind long delays or WiFi operations
+}

src/AccelStepper.cpp

@@ -38,6 +38,7 @@ void AccelStepper::move(long relative)
 // Implements steps according to the current step interval
 // You must call this at least once per step
 // returns true if a step occurred
+ISR_ATTR
 boolean AccelStepper::runSpeed()
 {
     // Dont do anything unless we actually have a step interval
@@ -69,6 +70,7 @@ boolean AccelStepper::runSpeed()
     }
 }
 
+ISR_ATTR
 long AccelStepper::distanceToGo()
 {
     return _targetPos - _currentPos;
@@ -95,6 +97,7 @@ void AccelStepper::setCurrentPosition(long position)
 }
 
 // Subclasses can override
+ISR_ATTR
 unsigned long AccelStepper::computeNewSpeed()
 {
     long distanceTo = distanceToGo(); // +ve is clockwise from curent location
@@ -182,6 +185,7 @@ unsigned long AccelStepper::computeNewSpeed()
 // You must call this at least once per step, preferably in your main loop
 // If the motor is in the desired position, the cost is very small
 // returns true if the motor is still running to the target position.
+ISR_ATTR
 boolean AccelStepper::run()
 {
     if (runSpeed())
@@ -325,6 +329,7 @@ float AccelStepper::speed()
 }
 
 // Subclasses can override
+ISR_ATTR
 void AccelStepper::step(long step)
 {
     switch (_interface)
@@ -381,6 +386,7 @@ long AccelStepper::stepBackward()
 // bit 0 of the mask corresponds to _pin[0]
 // bit 1 of the mask corresponds to _pin[1]
 // ....
+ISR_ATTR
 void AccelStepper::setOutputPins(uint8_t mask)
 {
     uint8_t numpins = 2;
@@ -394,6 +400,7 @@ void AccelStepper::setOutputPins(uint8_t mask)
 }
 
 // 0 pin step function (ie for functional usage)
+ISR_ATTR
 void AccelStepper::step0(long step)
 {
     (void)(step); // Unused
@@ -406,6 +413,7 @@ void AccelStepper::step0(long step)
 // 1 pin step function (ie for stepper drivers)
 // This is passed the current step number (0 to 7)
 // Subclasses can override
+ISR_ATTR
 void AccelStepper::step1(long step)
 {
     (void)(step); // Unused
@@ -423,6 +431,7 @@ void AccelStepper::step1(long step)
 // 2 pin step function
 // This is passed the current step number (0 to 7)
 // Subclasses can override
+ISR_ATTR
 void AccelStepper::step2(long step)
 {
     switch (step & 0x3)
@@ -447,6 +456,7 @@ void AccelStepper::step2(long step)
 // 3 pin step function
 // This is passed the current step number (0 to 7)
 // Subclasses can override
+ISR_ATTR
 void AccelStepper::step3(long step)
 {
     switch (step % 3)
@@ -469,6 +479,7 @@ void AccelStepper::step3(long step)
 // 4 pin step function for half stepper
 // This is passed the current step number (0 to 7)
 // Subclasses can override
+ISR_ATTR
 void AccelStepper::step4(long step)
 {
     switch (step & 0x3)
@@ -494,6 +505,7 @@ void AccelStepper::step4(long step)
 // 3 pin half step function
 // This is passed the current step number (0 to 7)
 // Subclasses can override
+ISR_ATTR
 void AccelStepper::step6(long step)
 {
     switch (step % 6)
@@ -528,6 +540,7 @@ void AccelStepper::step6(long step)
 // 4 pin half step function
 // This is passed the current step number (0 to 7)
 // Subclasses can override
+ISR_ATTR
 void AccelStepper::step8(long step)
 {
     switch (step & 0x7)

src/AccelStepper.h

@@ -289,6 +289,13 @@
  #define YIELD
 #endif
 
+// on archs defining IRAM_ATTR (esp8266, esp32), use this attribute for functions callable from ISR
+#ifdef IRAM_ATTR
+ #define ISR_ATTR IRAM_ATTR
+#else
+ #define ISR_ATTR
+#endif
+
 /////////////////////////////////////////////////////////////////////
 /// \class AccelStepper AccelStepper.h <AccelStepper.h>
 /// \brief Support for stepper motors with acceleration etc.

src/MultiStepper.cpp

@@ -49,6 +49,7 @@ void MultiStepper::moveTo(long absolute[])
 }
 
 // Returns true if any motor is still running to the target position.
+ISR_ATTR
 boolean MultiStepper::run()
 {
     uint8_t i;