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| 1 | +/* Author: Stephen Fordyce (adapted from WDT example code by Adam Garbo - https://forum.sparkfun.com/viewtopic.php?f=169&t=52431&p=213296&hilit=watchdog#p213296) |
| 2 | + Created: 24th July 2020 |
| 3 | + License: MIT. See SparkFun Arduino Apollo3 Project for more information |
| 4 | +
|
| 5 | + This example demonstrates use of the watchdog timer, also different ways of resetting the Artemis as well as how to determine the last reset type |
| 6 | +*/ |
| 7 | + |
| 8 | +// Global variables |
| 9 | +volatile uint8_t watchdogCounter = 0; // Watchdog interrupt counter |
| 10 | +uint32_t resetStatus = 0; // Reset status register |
| 11 | +bool testWatchdogResetFlag = false; |
| 12 | +bool watchdogInterruptCallsEmergencyReset = false; |
| 13 | +bool resetWDTEveryLoop = true; |
| 14 | + |
| 15 | +// Watchdog timer configuration structure. |
| 16 | +am_hal_wdt_config_t g_sWatchdogConfig = { |
| 17 | + //Substitude other values for AM_HAL_WDT_LFRC_CLK_16HZ to increase/decrease the range |
| 18 | + .ui32Config = AM_HAL_WDT_LFRC_CLK_16HZ | AM_HAL_WDT_ENABLE_RESET | AM_HAL_WDT_ENABLE_INTERRUPT, // Configuration values for generated watchdog timer event. |
| 19 | + //****** EVEN THOUGH THESE IMPLY 16-BIT, THEY ARE ONLY 8-BIT - 255 MAX! |
| 20 | + .ui16InterruptCount = 120, //MAX 255! // Set WDT interrupt timeout for 5 seconds (120 / 16 = 8). // Number of watchdog timer ticks allowed before a watchdog interrupt event is generated. |
| 21 | + .ui16ResetCount = 160 //MAX 255! // Set WDT reset timeout for 15 seconds (160 / 16 = 10). // Number of watchdog timer ticks allowed before the watchdog will issue a system reset. |
| 22 | +}; |
| 23 | + |
| 24 | +void setup(void) |
| 25 | +{ |
| 26 | + pinMode(LED_BUILTIN, OUTPUT); |
| 27 | + Serial.begin(115200); delay(10); |
| 28 | + Serial.println();Serial.println(); |
| 29 | + Serial.println("****Artemis Reset & Watchdog Reset Example****"); |
| 30 | + |
| 31 | + printResetReason(); //Explain reason for reset |
| 32 | + am_hal_reset_control(AM_HAL_RESET_CONTROL_STATUSCLEAR, 0); // Clear reset status register for next time we reset. |
| 33 | + delay(1000); |
| 34 | + |
| 35 | + startWatchdogTimer(); //Initialise and start the watchdog timer, in case the program gets stuck in a while loop or waiting for user input |
| 36 | + printWatchdogDetails(); |
| 37 | + delay(2000); |
| 38 | + |
| 39 | + Serial.println("\nRunning a time-consuming loop with watchdog running"); |
| 40 | + for(int i=0; i<5; i++) |
| 41 | + { |
| 42 | + delay(1000); //Phew, a bunch of hard processing |
| 43 | + printWatchdogValue(); |
| 44 | + } |
| 45 | + Serial.println("Yikes, the time kept increasing, even though we were doing legitimate work\n"); |
| 46 | + |
| 47 | + Serial.println("\nRunning a time-consuming loop that restarts the watchdog timer each loop"); |
| 48 | + for(int i=0; i<5; i++) |
| 49 | + { |
| 50 | + delay(1000); //Phew, a bunch of hard processing |
| 51 | + printWatchdogValue(); |
| 52 | + am_hal_wdt_restart(); // "Pet" the dog. // Restart the watchdog. |
| 53 | + } |
| 54 | + Serial.println("Plenty of time, but the watchdog timer will still catch a freeze\n"); |
| 55 | + delay(2000); |
| 56 | +} |
| 57 | + |
| 58 | +void loop(void) |
| 59 | +{ |
| 60 | + Serial.println("Start of loop()"); |
| 61 | + if(resetWDTEveryLoop) |
| 62 | + am_hal_wdt_restart(); // "Pet" the dog. // Restart the watchdog. (every loop run seems good) |
| 63 | + |
| 64 | + if(resetWDTEveryLoop) |
| 65 | + { |
| 66 | + Serial.println("Enter 'r' to do a scheduled software reset"); |
| 67 | + Serial.println("Enter 's' to stop resetting the watchdog timer each loop"); |
| 68 | + delay(1000); |
| 69 | + char option = Serial.read(); |
| 70 | + if(option == 'r') |
| 71 | + myScheduledReset(); |
| 72 | + if(option == 's') |
| 73 | + { |
| 74 | + Serial.println("I take no responsibility for the consequences!"); |
| 75 | + Serial.println("(the watchdog interrupt routine when triggered will reset the timer 3 times, watch the timer values to see when it's reset by the ISR)"); |
| 76 | + delay(2000); |
| 77 | + resetWDTEveryLoop = false; |
| 78 | + } |
| 79 | + } |
| 80 | + |
| 81 | + if(resetWDTEveryLoop == false) |
| 82 | + { |
| 83 | + Serial.println("Enter 'e' to let the watchdog interrupt call emergencyReset()"); |
| 84 | + delay(1000); |
| 85 | + char option = Serial.read(); |
| 86 | + if(option == 'e') |
| 87 | + { |
| 88 | + Serial.println("Cool, that'll happen in a sec"); delay(20); |
| 89 | + watchdogInterruptCallsEmergencyReset = true; |
| 90 | + } |
| 91 | + } |
| 92 | + |
| 93 | + if(testWatchdogResetFlag) |
| 94 | + { |
| 95 | + Serial.println("Just about to go down the rabbit hole..."); |
| 96 | + delay(20); //Let serial buffer clear |
| 97 | + while(1); //Intentionally get stuck, and hope that the watchdog timer saves the day |
| 98 | + } |
| 99 | + |
| 100 | + printWatchdogValue(); |
| 101 | + Serial.println(); |
| 102 | + delay(10); |
| 103 | + |
| 104 | + //Optional code for sleeping - just halt the WDT before you disable everything, then re-initialise the WDT after waking up. Tested elsewhere, and does not have any appreciable impact on sleep currents or performance |
| 105 | + //am_hal_wdt_halt(); |
| 106 | + //sleepForABit(); |
| 107 | + //startWatchdog(); |
| 108 | +} |
| 109 | + |
| 110 | +// Interrupt handler for the watchdog. |
| 111 | +extern "C" void am_watchdog_isr(void) |
| 112 | +{ |
| 113 | + am_hal_wdt_int_clear(); // Clear the watchdog interrupt. |
| 114 | + if(watchdogInterruptCallsEmergencyReset) |
| 115 | + emergencyReset(); |
| 116 | + |
| 117 | + if ( watchdogCounter < 3 ) // Catch the first three watchdog interrupts, but let the fourth through untouched. |
| 118 | + { |
| 119 | + digitalWrite(LED_BUILTIN, LOW); |
| 120 | + am_hal_wdt_restart(); // "Pet" the dog (reset the timer) |
| 121 | + } |
| 122 | + else |
| 123 | + { |
| 124 | + digitalWrite(LED_BUILTIN, HIGH); // Indicator that a reset will occur. |
| 125 | + testWatchdogResetFlag = true; |
| 126 | + } |
| 127 | + |
| 128 | + watchdogCounter++; // Increment the number of watchdog interrupts. |
| 129 | +} |
| 130 | + |
| 131 | +void startWatchdogTimer() |
| 132 | +{ |
| 133 | + am_hal_clkgen_control(AM_HAL_CLKGEN_CONTROL_LFRC_START, 0); // LFRC must be turned on for this example as the watchdog only runs off of the LFRC. |
| 134 | + am_hal_wdt_init(&g_sWatchdogConfig); // Configure the watchdog. |
| 135 | + NVIC_EnableIRQ(WDT_IRQn); // Enable the interrupt for the watchdog in the NVIC. |
| 136 | + am_hal_interrupt_master_enable(); |
| 137 | + am_hal_wdt_start(); // Enable the watchdog. |
| 138 | +} |
| 139 | + |
| 140 | +//IMPORTANT: IF THIS IS CALLED BY THE WATCHDOG TIMER INTERRUPT ROUTINE, IT NEEDS TO BE QUICK (NO PRINTING TO SERIAL OR DELAYS) |
| 141 | +void emergencyReset() |
| 142 | +{ |
| 143 | + //Optional: write some bits to flash/EEPROM to help with recovery |
| 144 | + |
| 145 | + am_hal_reset_control(AM_HAL_RESET_CONTROL_SWPOI,0); //Reset with option "Software Power On Initialization" SWPOI |
| 146 | +// am_hal_reset_control(AM_HAL_RESET_CONTROL_SWPOR,0); //Reset with option SWPOR (same as SWPOI but different am_hal_reset_status bit) |
| 147 | +} |
| 148 | + |
| 149 | +void myScheduledReset() |
| 150 | +{ |
| 151 | + //Optional: write some bits to flash/EEPROM to help with recovery |
| 152 | + |
| 153 | +// am_hal_reset_control(AM_HAL_RESET_CONTROL_SWPOI,0); //Reset with option "Software Power On Initialization" SWPOI |
| 154 | + am_hal_reset_control(AM_HAL_RESET_CONTROL_SWPOR,0); //Reset with option SWPOR (same as SWPOI but different am_hal_reset_status bit) |
| 155 | +} |
| 156 | + |
| 157 | +void printWatchdogDetails() |
| 158 | +{ |
| 159 | + Serial.print("Interrupt Count = "); Serial.print(g_sWatchdogConfig.ui16InterruptCount ); Serial.println(" ticks"); |
| 160 | + Serial.print("Reset Count = "); Serial.print(g_sWatchdogConfig.ui16ResetCount); Serial.println(" ticks"); |
| 161 | + |
| 162 | + // Print out reset status register. |
| 163 | + am_hal_reset_status_t sStatus; // (Note: See am_hal_reset.h for RESET status structure) |
| 164 | + am_hal_reset_status_get(&sStatus); |
| 165 | + resetStatus = sStatus.eStatus; |
| 166 | + char rStatus[30]; |
| 167 | + sprintf(rStatus, "Reset Status Register = 0x%x", resetStatus); // (Note: Watch Dog Timer reset = 0x40) |
| 168 | + Serial.println(rStatus); |
| 169 | +} |
| 170 | + |
| 171 | +void printWatchdogValue() |
| 172 | +{ |
| 173 | + Serial.print("Watchdog timer:"); |
| 174 | + Serial.println(am_hal_wdt_counter_get()); |
| 175 | +} |
| 176 | + |
| 177 | +void printResetReason() |
| 178 | +{ |
| 179 | + am_hal_reset_status_t resetResult; |
| 180 | + uint32_t resultOk = am_hal_reset_status_get(&resetResult); |
| 181 | + Serial.print("Reset reason: "); |
| 182 | + if(resultOk == AM_HAL_STATUS_FAIL) Serial.println("Failed to get reset status"); |
| 183 | + if(resetResult.bEXTStat) Serial.println("External reset"); |
| 184 | + if(resetResult.bPORStat) Serial.println("Power-On reset"); |
| 185 | + if(resetResult.bBODStat) Serial.println("Brown-Out reset"); |
| 186 | + if(resetResult.bSWPORStat) Serial.println("SW Power-On reset or AIRCR reset - in this example, indicates reset by myScheduledReset()"); |
| 187 | + if(resetResult.bSWPOIStat) Serial.println("SW Power On Initialization reset - in this example, indicates reset by emergencyReset()"); |
| 188 | + if(resetResult.bDBGRStat) Serial.println("Debugger reset"); |
| 189 | + if(resetResult.bWDTStat) Serial.println("Watch Dog Timer reset - nothing in the Watchdog Timer Interrupt routine got to restarting the Watchdog Timer"); |
| 190 | + if(resetResult.bBOUnregStat) Serial.println("Unregulated Supply Brownout event"); |
| 191 | + if(resetResult.bBOCOREStat) Serial.println("Core Regulator Brownout event"); |
| 192 | + if(resetResult.bBOMEMStat) Serial.println("Memory Regulator Brownout event"); |
| 193 | + if(resetResult.bBOBLEStat) Serial.println("BLE/Burst Regulator Brownout event"); |
| 194 | +// am_hal_reset_control(AM_HAL_RESET_CONTROL_STATUSCLEAR, 0); // (do this in setup() Clear reset status register for next time we reset. |
| 195 | + Serial.println(); |
| 196 | +} |
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