poolguy.ino

/*
    PoolGuy project; main firmware file

    Hardware configuration:
        MCU:                    Arduino MKR 1010 WiFi (SAMD21)
        TEMP SENSOR:            DSB18B20 ONEWIRE    (Connected to D8)
*/


#include "defines.h"

#include <OneWire.h>
#include <DallasTemperature.h>
#include <StateMachine.h>
#include <ArduinoLowPower.h>
#include <ArduinoHttpClient.h>
#include <MKRGSM.h>
#include <ArduinoJson.h>

/* Constants */
unsigned long awoke_millis = millis();


/* Method declarations */
void idle();
void transmit_data();
void gsm_connect();
void deep_sleep();

/* States enums */
enum class States
{
    IDLE,
    TRANSMIT_DATA,
    GSM_CONNECT,
    DEEP_SLEEP
};


/* Globally accessible singletons */

OneWire oneWire(TEMP_SENSOR_PIN);
DallasTemperature sensors(&oneWire);

StateMachine<States> stateMachine = StateMachine<States>(States::IDLE, idle);


void setup()
{
    #if DEVMODE
        Serial.begin(38400);
    #endif

    /* Configure peripherals */
    pinMode(STATUS_LED_PIN, OUTPUT);
    
    /* Configure StateMachine instance with states and chains */
    stateMachine.addState(States::TRANSMIT_DATA, transmit_data);
    stateMachine.addState(States::GSM_CONNECT, gsm_connect);
    stateMachine.addState(States::DEEP_SLEEP, deep_sleep);

    stateMachine.setChainedState(States::TRANSMIT_DATA, States::DEEP_SLEEP);
}


float read_battery_voltage()
{
    uint16_t battery_level;

    /* Read the value on ADC_BATTERY ( 0 - 1023 ) */
    battery_level = analogRead(ADC_BATTERY);
    float voltage = 0.0;
    
    /* Convert the analog reading (which goes from 0 - 1023) to a voltage (0 - 4.3V): */
    float readvoltage = (battery_level * (4.3 / 1023.0)) * 0.969543;
  
    /* round value by two precision */
    voltage = roundf(readvoltage * 100) / 100;
    
    return voltage;
}


int read_batterylevel()
{
    float voltage = read_battery_voltage();
    float output = round((voltage - BATT_MIN_V) / (BATT_MAX_V - BATT_MIN_V) * 100);

    if (output >= 0 && output < 100)
    {
        return round(output);   
    }      
    else if (output < 0)
    {
        return 1;
    }
    return 100;
}


void deep_sleep()
{
    // Calculate how long it took to perform 
    // the workload and deduct it from the sleep time.
    unsigned long time_awake = millis() - awoke_millis;
    unsigned long sleep_time = INTERVAL - time_awake;
        
    if (sleep_time > 0)
    {
        LowPower.sleep(sleep_time);
        awoke_millis = millis();
    }
    stateMachine.release();    
}


void transmit_data()
{    
    char serialized_json_output[128];
    
    byte isCharging = 0;
    float voltage = read_battery_voltage();
    int batterylevel = read_batterylevel();
    float waterTemperature;
    char product_name[] = PRODUCT_NAME;
    char device_id[] = DEVICE_ID;
    
    
    GSMClient gsmClient;
    GPRS gprs;
    GSM gsmAccess;
    HttpClient client = HttpClient(gsmClient, SERVER_ROOT, SERVER_PORT);
    client.setTimeout(10 * SECOND);
    
    sensors.requestTemperatures();
    waterTemperature = sensors.getTempCByIndex(0);

    if (voltage > BATT_MAX_V)
        isCharging = 1;

    Serial.print("Temperature: ");
    Serial.println(waterTemperature);       
    return;
  
    // Assemble the body of the POST message:
    StaticJsonDocument<128> json_document;

    json_document["product_name"] = "Poolguy";
    json_document["water_temp"] = waterTemperature;
    json_document["battery_level"] = batterylevel;
    json_document["pwr_bus_voltage"] = voltage;
    json_document["is_charging"] = isCharging;
        
    
    // Serialize the JSON object to char array
    serializeJson(json_document, serialized_json_output);

    #if DEVMODE
        Serial.println(serialized_json_output);
    #endif

    while (1) {
        flash(3, 1000);
        digitalWrite(STATUS_LED_PIN, 1);
        if ((gsmAccess.begin(SIM_PIN) == GSM_READY) && (gprs.attachGPRS(GPRS_APN, GPRS_LOGIN, GPRS_PW) == GPRS_READY))
            break;
        
        delay(1000);
    }


    // send the POST request
    client.post(SUB_PATH, CONTENT_TYPE, serialized_json_output);
        
    #if DEVMODE
        // read the status code and body of the response
        int status_code = client.responseStatusCode();
        Serial.print("Sent a request to: ");
        Serial.print(SERVER_ROOT); Serial.print("/"); Serial.print(SUB_PATH);
        Serial.print("Status code: ");
        Serial.println(status_code);
        Serial.print("Response: ");
        Serial.println(client.responseBody());
    #endif

    flash(10, 150);

    stateMachine.release();
}


int flash(int times, int ms_delay)
{
    int state = 0;
    for (int i = 0; i < times * 2; i++)
    {
        digitalWrite(STATUS_LED_PIN, state);
        delay(ms_delay);
        state = !state;
    }
    digitalWrite(STATUS_LED_PIN, 0);
}


void gsm_connect()
{
    
    #if DEVMODE
        Serial.print("Connecting to GSM... ");
    #endif
          

}


void idle()
{   
    stateMachine.transitionTo(States::TRANSMIT_DATA);
}


void loop() 
{
    stateMachine.next()();
}