/* 1-14-2013 Spark Fun Electronics Nathan Seidle When the ATtiny senses water between two pins, go crazy. Make noise, blink LED. To use this code you must configure the ATtiny to run at 8MHz so that serial and other parts of the code work correctly. We take a series of readings of the water sensor at power up. We then wait for a deviation of more than 100 from the average before triggering the alarm. The alarm will run for a minimum of 2 seconds before shutting down. This firmware uses some power saving to get the average consumption down to ~50uA average. With a CR2032 @ 200mAh this should allow it to run for 4,000hrs or 166 days. This is easily extended by increasing the amount of time between water checks (currently 1 per second). 12-2017 - Adapted for AdaFruit Trinket M0 */ #include #include #include #include // abs() is broken for the M0. Basically negative in yields negative out! #undef abs() //#define DEBUG_SERIAL // If enabled debug messages emitted over the serial port //#define DEBUG_SLEEP // If enabled the status LED is used to debug sleep periods // Define I/O's #define BUZZER1 0 // One pin of the piezo buzzer #define BUZZER2 4 // Other pin of the piezo buzzer #define ALARM_LED 1 // Alarm LED pin #define STAT_LED 13 // Status LED pin #define WATER_SENSOR A1 // Analog input pin for water sensor // A difference of more than 100 on the analog input with respect to the average // computed during startup will trigger the system #define MAX_DIFFERENCE 100 // Assumes external 10K ohm pull-up to Vbat // Two different sleep period are used to conserve power if the battery is left in circuit when the leak // detector is not in use. A longer sleep of 8 seconds is employed during standby. Once triggered (e.g. test prior // a sequence of dives) shifts the detector to a 2 second sleep period. After approximately two weeks where no leak // is detected the detector shifts back to the standby sleep period. // Sleep longer in standby #define MAX_SHORT_SLEEP 0x200000 // About 2 weeks of 2 second sleep periods #define ACTIVE_SLEEP_PERIOD 2000 // 2 seconds #define STANDBY_SLEEP_PERIOD 8000 // 8 seconds int waterAvg = 0; // Average analog value found during startup. bool standbyState = true; // Initially the detector starts up in standby with a longer sleep period long standbyDelay = MAX_SHORT_SLEEP; // Delay over which if no trigger occurs the detector shifts back to standby // The ABS() define appears to be broken for the M0 int abs(int v) { if (v >= 0) return (v); else return (v*-1); } void setup() { delay(1000); // Ensure we can get into the boot loader before sleep #ifdef DEBUG_SERIAL while (!Serial); Serial.begin(115200); Serial.println("H2Ohno!"); #endif // Setup I/O pins pinMode(BUZZER1, OUTPUT); pinMode(BUZZER2, OUTPUT); pinMode(ALARM_LED, OUTPUT); pinMode(STAT_LED, OUTPUT); pinMode(WATER_SENSOR, INPUT); //Take a series of readings from the water sensor and average them waterAvg = 0; for(int x = 0 ; x < 8 ; x++) { waterAvg += analogRead(WATER_SENSOR); delay(50); } waterAvg /= 8; #ifdef DEBUG_SERIAL Serial.print("Avg: "); Serial.println(waterAvg); #endif //During power up, sound the buzzer to verify its function alarmSound(); delay(100); alarmSound(); // Set the I/O's to a low power state digitalWrite(BUZZER1, LOW); digitalWrite(BUZZER2, LOW); digitalWrite(STAT_LED, LOW); digitalWrite(ALARM_LED, LOW); // We don't use the temperature sensor, disable its reference system_voltage_reference_disable(SYSTEM_VOLTAGE_REFERENCE_TEMPSENSE); } void loop() { int waterDifference; long startTime; long timeSinceBlink; int actualSleep; if (standbyState == false) if (standbyDelay-- <= 0) standbyState = true; // Sleep with the ADC's reference off system_voltage_reference_disable(SYSTEM_VOLTAGE_REFERENCE_BANDGAP); if (standbyState == false) actualSleep = Watchdog.sleep(ACTIVE_SLEEP_PERIOD); else actualSleep = Watchdog.sleep(STANDBY_SLEEP_PERIOD); system_voltage_reference_enable(SYSTEM_VOLTAGE_REFERENCE_BANDGAP); #ifdef DEBUG_SERIAL Serial.print("Actual sleep = "); Serial.println(actualSleep); #endif #ifdef DEBUG_SLEEP // Blip the status LED during water sensor sampling digitalWrite(statLED, HIGH); #endif //Check for water waterDifference = abs(analogRead(WATER_SENSOR) - waterAvg); #ifdef DEBUG_SLEEP digitalWrite(statLED, LOW); #endif #ifdef DEBUG_SERIAL Serial.print("Diff: "); Serial.println(waterDifference); #endif if(waterDifference > MAX_DIFFERENCE) { if (standbyState == true) { standbyState = false; standbyDelay = MAX_SHORT_SLEEP; } startTime = millis(); // Record the current time for blinking timeSinceBlink = startTime; // Loop until we don't detect water AND 10 seconds of alarm has expired while(waterDifference > MAX_DIFFERENCE || (millis() - startTime) < 10000) { alarmSound(); // Short on pulse, with 1 second period if ((digitalRead(ALARM_LED) == HIGH) && (millis() - timeSinceBlink > 10)) { timeSinceBlink = millis(); digitalWrite(ALARM_LED, LOW); } if ((digitalRead(STAT_LED) == LOW) && (millis() - timeSinceBlink > 1000)) { timeSinceBlink = millis(); digitalWrite(ALARM_LED, HIGH); } waterDifference = abs(analogRead(WATER_SENSOR) - waterAvg); // Take a new reading #ifdef DEBUG_SERIAL Serial.print("Read: "); Serial.println(analogRead(WATER_SENSOR)); #endif } //No more alarm. Ensure LEDs and buzzer are off digitalWrite(BUZZER1, LOW); // Technical needs to transition to consume power digitalWrite(BUZZER2, LOW); // but set to low as the default off state digitalWrite(STAT_LED, LOW); digitalWrite(ALARM_LED, LOW); } } // This is just a unique (annoying) sound we came up with, there is no magic to it // Comes from the Simon Says game/kit actually: https://www.sparkfun.com/products/10547 // 250us to 79us void alarmSound(void) { // Toggle the buzzer at various speeds for (byte x = 200 ; x > 70; x--) { for (byte y = 0 ; y < 3 ; y++) { digitalWrite(BUZZER2, HIGH); digitalWrite(BUZZER1, LOW); delayMicroseconds(x); digitalWrite(BUZZER2, LOW); digitalWrite(BUZZER1, HIGH); delayMicroseconds(x); } } }