fix step motor over heating after stop,and auto reboot in new version of firmware.

README.md

@@ -5,7 +5,7 @@ With this module you can drive a stepper motor in 3 lines like this
 ```lua
 stepper  = require ('stepper')
 stepper.init({5,6,7,8})
-stepper.rotate(stepper.FORWARD,2500,5,0,function () print('Rotation done.') end)
+stepper.rotate(stepper.FORWARD,2500,5,function () print('Rotation done.') end)
 ```
 As you can see, your code trigger rotate and let the module finish rotation and trigger callback. 
 
@@ -63,7 +63,7 @@ Note : this is a async method. It'll trigger rotation and return immediately.
 
 ##### Signature : 
 ```lua
-rotate( direction, desired_steps, interval, timer_to_use, callback)
+rotate( direction, desired_steps, interval, callback)
 ```
 
 ##### Parameters : 
@@ -73,7 +73,6 @@ rotate( direction, desired_steps, interval, timer_to_use, callback)
 | **direction** | _stepper.FORWARD or stepper.REVERSE_ |
 | **desired_steps** | _number between 0 to infinity - 2500 is default which is roughly half a rotation_ |
 | **interval** | _time delay in milliseconds between steps, smaller self number is, faster the motor rotates . 5 is default_ |
-| **timer_to_use** | _which nodemcu timer to use, 0 is default_ |
 | **callback** | _callback to invoke on completion of given rotation |
 
 
@@ -82,9 +81,9 @@ rotate( direction, desired_steps, interval, timer_to_use, callback)
 ```lua
 direction = stepper.FORWARD 
 desired_steps = 2500 
-interval = 5 
+interval = 1 
 timer_to_use = 0 
-stepper.rotate(direction,desired_steps,interval,timer_to_use,function ()
+stepper.rotate(direction,desired_steps,interval,function ()
     print('Rotation done. inside callback.')
     -- do some thing useful 
     end)
@@ -94,5 +93,5 @@ stepper.rotate(direction,desired_steps,interval,timer_to_use,function ()
 ```lua
 stepper  = require ('stepper')
 stepper.init({5,6,7,8})
-stepper.rotate(stepper.FORWARD,2500,5,0,function () print('Rotation done.') end)
+stepper.rotate(stepper.FORWARD,2500,5,function () print('Rotation done.') end)
 ```

stepper.lua

@@ -36,6 +36,7 @@ do
     -- motor configuration data
     ---------------------------------------------------------------------------------------
     local motor_params = {}
+    local motor_timer = tmr.create()
 
     -- nodemcu pin numbers on which to motor is connected
     motor_params.pins = {5,6,7,8}
@@ -47,7 +48,6 @@ do
     motor_params.step_interval = 5 -- milliseconds decides the speed. smaller the interval, higher the speed.
     motor_params.desired_steps = 2500
     motor_params.direction = FORWARD
-    motor_params.timer_to_use = 0
     motor_params.callback = nil
 
 
@@ -84,7 +84,10 @@ do
         --increment the counter and check if there are steps to execute
         step_counter = step_counter + 1
         if step_counter > motor_params.desired_steps then
-            tmr.stop(motor_params.timer_to_use)
+            motor_timer:stop()
+            for index,mcu_pin in ipairs(motor_params.pins) do
+                gpio.write(mcu_pin, gpio.LOW)
+            end
             node.task.post(2, motor_params.callback) -- node.task.HIGH_PRIORITY = 2
         else
             updatePhaseForNextStep();
@@ -108,7 +111,7 @@ do
         -- D8 < ------ > IN4
     local init = function ( pins )
         if not pins or not interval then
-            print('Init params missing !!! initializing with defaults')
+            --print('Init params missing !!! initializing with defaults')
             local motor_pins = motor_params.pins;
             for i,pin in ipairs( motor_pins ) do
                 gpio.mode(pin, gpio.OUTPUT)
@@ -128,17 +131,17 @@ do
         -- direction = stepper.FORWARD or stepper.REVERSE
         -- desired_steps = number between 0 to infinity - 2500 is default
         -- interval = time delay in milliseconds between steps, smaller self number is, faster the motor rotates . 5 is default
-    local rotate = function ( direction, desired_steps, interval, timer_to_use, callback)
+    local rotate = function ( direction, desired_steps, interval, callback)
         motor_params.step_interval = interval -- milliseconds decides the speed. smaller the interval, higher the speed.
         motor_params.desired_steps = desired_steps
         motor_params.direction = direction
-        motor_params.timer_to_use = timer_to_use
         motor_params.callback = callback
 
         step_counter  = 0
         phase         = 1
 
-        tmr.alarm(motor_params.timer_to_use, motor_params.step_interval, REPEATING_TIMER, single_step)
+        --tmr.alarm(motor_params.timer_to_use, motor_params.step_interval, REPEATING_TIMER, single_step)
+        motor_timer:alarm(motor_params.step_interval, REPEATING_TIMER, single_step)
     end
 
     stepper = {

stepper_test.lua

@@ -1,9 +1,8 @@
 stepper  = require ('stepper')
 stepper.init()
 desired_steps = 2500
-interval = 5
-timer_to_use = 0
+interval = 1
 print('stepper.rotate() - start')
-stepper.rotate(stepper.FORWARD,desired_steps,interval,timer_to_use,function ()
+stepper.rotate(stepper.FORWARD,desired_steps,interval,function ()
     print('Rotation done. inside callback.')
     end)