Add WDT, boot.py file to disable WDT at soft reboot, modify startup display message

lib/menu_display.py

@@ -111,10 +111,13 @@ def display_show_error(robot):
     robot.display.centered_text('error!', 30, 1)
     robot.display.show()
 
-def display_show_startup(robot):
+def display_show_startup(robot, reset):
     robot.display.fill(0)
-    robot.display.centered_text('Turning', 20, 1)
-    robot.display.centered_text('on', 30, 1)
+    if reset:
+        robot.display.centered_text('Resetting', 20, 1)
+    else:
+        robot.display.centered_text('Turning', 20, 1)
+        robot.display.centered_text('on', 30, 1)
     robot.display.show()
 
 def display_show_program(robot):

lib/robot.py

-from machine import Pin, I2C, Timer
+from machine import Pin, I2C, Timer, WDT
 from time import sleep, ticks_ms
 
 from lib.cube import Buzzer, I2CGuard, SH1106_I2C, Esp, I2C_master
@@ -6,7 +6,7 @@ from lib import nxt, ev3, OC
 
 from lib.hw_defs.ports import SENSOR_PORT_PINS, MOTOR_PORT_PINS
 from lib.hw_defs.pins import *
-from lib.robot_consts import Sensor,Button, BAT_VOLTAGE_TURNOFF, BAT_MEASURE_PERIOD, I2C_FREQ, PCF_CHECK_PERIOD, FW_VERSION
+from lib.robot_consts import Sensor,Button, BAT_VOLTAGE_TURNOFF, BAT_TURNOFF_PERIODS, BAT_MEASURE_PERIOD, I2C_FREQ, PCF_CHECK_PERIOD, FW_VERSION
 
 import motors_ll
 import brick_ll
@@ -48,16 +48,37 @@ class Robot:
 
         # Initialize periodic cube buttons state read on PCF 
         self.cube_startup = True
-        self.pcf_timer = Timer(-1)
+        self.pcf_timer = Timer(-1) 
         self.pcf_timer.init(mode=Timer.PERIODIC, period=PCF_CHECK_PERIOD,
                             callback=self.read_buttons)
         
-        # Timer is used to check if the batteries are charged enough, turn off cube if not 
+        # Timer is used to check if the batteries are charged enough, turn off cube if not
+        # counter -1 to grant extra period at cube startup so the battery multiplier can be set
+        self.battery_low_counter = -1
         self.battery_timer = Timer(-1)
         self.battery_timer.init(mode=Timer.PERIODIC, period=BAT_MEASURE_PERIOD,
                                 callback=self.check_battery_low)
+        
+        self.wdt = WDT(timeout=4000)
+        print("Watch Dog Timer initialised with timeout 4 s.")
+        self.wdt_feed_timer = Timer(-1)
+        self.wdt_feed_timer.init(period=3500, mode=Timer.PERIODIC,
+                                 callback=self.wdt_feed)
     
+    # Function called with a timer to feed Watch Dog Timer to prevent rebooting
+    def wdt_feed(self, t):
+        self.wdt.feed()
     
+    # Turn off cube
+    def turn_off(self):
+        self.turn_off_pin.value(1)
+        sleep(0.096)
+        self.led.on()
+        self.turn_off_pin.value(0) # resetting pin for quick startup
+        sleep(1)
+        while True:
+            self.turn_off_pin.value(1)
+            
     # Read cube buttons state on timer interrupt ant turn off cube if power button pressed
     def read_buttons(self, p):
         self.buttons.read_value()
@@ -70,13 +91,7 @@ class Robot:
             self.display.centered_text('Turning off', 30, 1)
             self.display.show()
             sleep(0.3)
-            self.turn_off_pin.value(1)
-            sleep(0.096)
-            self.led.on()
-            self.turn_off_pin.value(0)
-            sleep(1)
-            while True:
-                self.turn_off_pin.value(1)
+            self.turn_off()
                 
     def fw_version(self):
         return FW_VERSION
@@ -154,16 +169,24 @@ class Robot:
     # Check if the battery voltage is too low,
     # if it is make buzzer sound, show info on the display and turn off the cube
     def check_battery_low(self, p):
+        print(self.battery.voltage() , self.battery_low_counter)
         if self.battery.voltage() < BAT_VOLTAGE_TURNOFF:
-            self.buzzer.set_freq_duty(1000, 0.05)
-            self.display.fill(0)
-            self.display.text('Battery low!', 15, 30, 1)
-            self.display.show()
-            sleep(1)
-            self.buzzer.off()
-            sleep(3)
-            self.deinit_all()
-            self.buttons.turn_off_cube()
+            self.battery_low_counter += 1
+            if self.battery_low_counter >= BAT_TURNOFF_PERIODS:
+                #self.buzzer.set_freq_duty(1000, 0.05)
+                self.display.fill(0)
+                self.display.text('Battery low!', 15, 30, 1)
+                self.display.show()
+                self.wdt_feed(None) # Feed WDT to prevent rebooting
+                sleep(1)
+                self.wdt_feed(None)
+                self.buzzer.off()
+                sleep(3)
+                self.wdt_feed(None)
+                self.deinit_all()
+                self.turn_off()
+        else:
+            self.battery_low_counter = 0
 
 
 # Helper object for storing, initializing and deinitializing sensor objects

lib/robot_consts.py

@@ -76,6 +76,7 @@ class Color:
 
 
 BAT_MEASURE_PERIOD = const(1000)	# ms
+BAT_TURNOFF_PERIODS = 2
 BAT_VOLTAGE_MAX = 8.4
 BAT_VOLTAGE_MIN = 6.2
 BAT_VOLTAGE_TURNOFF = (BAT_VOLTAGE_MIN+0.1)			# Volts

main/boot.py

+# Disable Watchdog timer after a soft boot
+machine.mem32[0x40058000] = machine.mem32[0x40058000] & ~(1<<30)
\ No newline at end of file

main/main.py

+import micropython
+# Allocate exception buffer for interrupt handlers
+micropython.alloc_emergency_exception_buf(100)
+
+import machine
 from lib.robot import Robot
 from lib.menu_display import display_show_startup
+
 # Initialize global robot object
 robot = Robot()
-
-display_show_startup(robot)
+# machine.WDT_RESET = hard and soft reboot or WDT reboot
+display_show_startup(robot, machine.WDT_RESET == machine.reset_cause())
 
 import time
 import os
 import sys
-import micropython
 import gc
-import machine
 
 import menu_programs
 
@@ -21,8 +25,7 @@ try:
 except:
     from lib.default_config import esp_default_name, battery_multiplier
 
-# Allocate exception buffer for interrupt handlers
-micropython.alloc_emergency_exception_buf(100)
+robot.battery.set_multiplier(battery_multiplier)
 
 def main():
     # File and directory constants for browsing user programs
@@ -62,7 +65,8 @@ def main():
                 f.write("Previous log too long, file deleted\n")
                 f.write("--------------------------------------------------\n")
             f.write(f"ERROR program: {program_name}, time since reset: {int(time.ticks_diff(time.ticks_ms(),robot.start_time))} ms\n")
-            sys.print_exception(e, f)
+            if e:
+                sys.print_exception(e, f)
             f.write("--------------------------------------------------\n")
 
     # Analyze pressed buttons for menu movement 
@@ -145,8 +149,6 @@ def main():
     bt_connecting = False
     button_values = robot.buttons.pressed()
     esp_reset_failed_counter = 0
-    display_show_startup(robot)
-    robot.battery.set_multiplier(battery_multiplier)
 
     # Get a list of user programs
     program_list = []
@@ -174,6 +176,7 @@ def main():
 
     # Loop that shows display, controls menu and starts user programs
     while(True):
+        #print(micropython.mem_info())
         # Connect to and reset ESP32 to BT mode if it is not running
         
         if not robot.esp.running() and counter % 10 == 0: