Published June 30, 2021 © GPL3+

Basement Monitoring Using Wio Terminal and Blynk

Monitoring basement to make sure humidity does not rise too high and alert to check if dehumidifier bucket is full.

IntermediateFull instructions provided5 hours3,452

Basement Monitoring Using Wio Terminal and Blynk

Things used in this project

Hardware components

Seeed Studio Wio Terminal

Pimoroni BME680 Breakout

Software apps and online services

Arduino IDE

Blynk

Edge Impulse Studio

Hand tools and fabrication machines

3D Printer (generic)

Story

Motivation

I live in East Coast of USA where most of the houses have basements, some are finished, some are not. Our basement is semi-finished which means proper dehumidification is not setup. In non-finished basements we need to make sure humidity does not rise too much for a long period of time which helps molds to grow. Toxic mold can irritate your eyes, your respiratory system and cause very unpleasant odors in your basement. Mold can trigger asthma attacks and cause serious problems for individuals who have weakened immune systems. So keeping basement dry is very important thing.

I have a dehumidified running all the time in basement which keeps the basement dry. But problem is, the unit shuts off when the bucket is full of water and eventually humidity goes high. I need to periodically go in the basement and make sure unit is running and empty the bucket when it's full. But sometimes I forget to check for a week or two.

Solution

I am making a device using Wio Terminal and BME680 environmental sensor which will measure temperature, humidity, indoor air quality (IAQ) and noise level. Data will be displayed on the Wio Terminal and also sent to Blynk. When humidity goes beyond pre-defined threshold ( configurable via Blynk app ), Blynk will send push notification to my phone so that I never miss to empty the bucket.

Air Quality Monitoring

BME680 sensor can help measure indoor air quality. It's a very important data point specially for my basement as oil tank is situated in the basement along with heating unit. If there is any leakage, it will produce bad smell and IAQ would go high. In an event of this, Blynk will send me push notification.

Blynk Dashboard

Though Wio Terminal has nice display but it's more convenient to see the sensor data from your Blynk app. Every seconds, Wio Terminal sends data to Blynk server which is displayed on the app.

How To Integrate Wio Terminal With Blynk

I am not going to document the steps here as there is a superb documentation already available on seeedstudio wiki.

In my project, I have used four guages, one slider, one chart and one notification widget. 4 guages are linked to 4 virtual pins.

Blynk.virtualWrite(V1, t);
Blynk.virtualWrite(V2, h);
Blynk.virtualWrite(V3, a);
Blynk.virtualWrite(V4, avg);

Humidity threshold is connected to slider which determines when to send notification

BLYNK_WRITE(V0)
{
//reads the slider value when it changes in the app
humidityThreshold = param.asInt();
}
if(h > humidityThreshold ){
if(lastNotification == 0 || (millis() - lastNotification) > 60*60*1000){
lastNotification = millis();
Blynk.notify("Basement is too humid. Check the dehumidifier");
}
}

Final Product In Action

So, finally I 3D printed the enclosure and screwed on the basement door frame.

Unit Status Prediction

I am planning to use tinyML ( using Edge Impulse Studio) to analyze the audio coming from dehumidifier and classify is the unit is running or in stand by.

Follow this tutorial to get started with Edge Impulse.

If you don't know, EI is a web based tool where you can collect data, build your inference model, test your model performance and finally deploy to your microcontroller. It's free. I highly recommend you to signup your free account and tinker with it.

I have collected around 3 minutes of data. Honestly, in the basement, there is no other noise except the dehumidifier or when we have game time or movie night. So 3m is OK.

For the signal processing block, I tried both MFCC and MFE. I found better result with MFE.

Then I download Arduino library. Note - the example in the library is written for Nano BLE Sense which uses PDM module to capture sound from microphone. So you need to make some changes in your Wio code. Follow dehumifier_tinyml.ino file to hook up EI sdk with your code.

Prediction is running every seconds but we are sending data to Blynk every 10 seconds. Also prediction can be wrong sometimes, so it's better to take average and eliminate outliers.

Unit status displayed on Blynk

Circuit Diagram

BME680 3V3 - WIO 3V3 (1)

BME680 GND - WIO GND (9)

BME680 SDA/SDI - WIO SDA (3)

BME680 SCL/SCK - WIO SCL (5)

This project is published on PCBWay as well.

Schematics

Code

#define BLYNK_PRINT Serial

/* Includes ---------------------------------------------------------------- */
#include <rpcWiFi.h>
#include <WiFiClient.h>
#include <BlynkSimpleWioTerminal.h>
#include <TFT_eSPI.h> //TFT LCD library 
#include <bsec.h>

char auth[] = "token";
char ssid[] = "ssid";
char pass[] = "password";
BlynkTimer timer;



TFT_eSPI tft; //Initializing TFT LCD
TFT_eSprite spr = TFT_eSprite(&tft); //Initializing buffer
Bsec iaqSensor;
String output;
void checkIaqSensorStatus(void);

int t = 0, h = 0, a = 0, p = 0, s = 0, avg = 0;
int sum = 0; int count = 0;

long WIO_RESET_INTERVAL_IN_MINUTES = 60;


/**
   @brief      Arduino setup function
*/
void setup()
{
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(WIO_MIC, INPUT);

  tft.begin(); //Start TFT LCD
  tft.setRotation(3); //Set TFT LCD rotation

  tft.setTextSize(2);
  tft.fillScreen(TFT_BLACK);
  tft.drawString("Connecting to Blynk...", 20, 120);

  Blynk.begin(auth, ssid, pass);
  timer.setInterval(1000L, sendPrediction);
  Blynk.syncAll();

  tft.fillScreen(TFT_BLACK);

  //Setting the title header
  //tft.fillScreen(TFT_WHITE); //Fill background with white color
  tft.fillRect(0, 0, 320, 50, TFT_YELLOW); //Rectangle fill with dark green
  tft.setTextColor(TFT_BLACK); //Setting text color
  tft.setTextSize(3); //Setting text size
  tft.drawString("Basement", 50, 10); //Drawing a text string



  tft.drawFastVLine(150, 50, 160, TFT_DARKGREEN); //Drawing verticle line
  tft.drawFastHLine(0, 130, 320, TFT_DARKGREEN); //Drawing horizontal line
  tft.drawFastHLine(0, 210, 320, TFT_DARKGREEN); //Drawing horizontal line 2

  tft.setTextColor(TFT_LIGHTGREY);
  tft.setTextSize(1);
  tft.drawString("Temperature", 10, 60);

  tft.setTextSize(1);
  tft.drawString("Humidity", 10, 140);

  tft.setTextSize(1);
  tft.drawString("IAQ", 160, 60);

  tft.setTextSize(1);
  tft.drawString("Noise", 160, 140);



  Wire.begin();
  iaqSensor.begin(BME680_I2C_ADDR_SECONDARY, Wire);
  checkIaqSensorStatus();
  bsec_virtual_sensor_t sensorList[10] = {
    BSEC_OUTPUT_RAW_TEMPERATURE,
    BSEC_OUTPUT_RAW_PRESSURE,
    BSEC_OUTPUT_RAW_HUMIDITY,
    BSEC_OUTPUT_RAW_GAS,
    BSEC_OUTPUT_IAQ,
    BSEC_OUTPUT_SENSOR_HEAT_COMPENSATED_TEMPERATURE,
    BSEC_OUTPUT_SENSOR_HEAT_COMPENSATED_HUMIDITY,
  };

  iaqSensor.updateSubscription(sensorList, 7, BSEC_SAMPLE_RATE_LP);
  checkIaqSensorStatus();

}

void checkIaqSensorStatus(void)
{
  if (iaqSensor.status != BSEC_OK) {
    if (iaqSensor.status < BSEC_OK) {
      output = "BSEC error code : " + String(iaqSensor.status);
      Serial.println(output);
      while (true) {

      }

    } else {
      output = "BSEC warning code : " + String(iaqSensor.status);
      Serial.println(output);
    }
  }

  if (iaqSensor.bme680Status != BME680_OK) {
    if (iaqSensor.bme680Status < BME680_OK) {
      output = "BME680 error code : " + String(iaqSensor.bme680Status);
      Serial.println(output);
      while (true) {

      }
    } else {
      output = "BME680 warning code : " + String(iaqSensor.bme680Status);
      Serial.println(output);
    }
  }
}

long lastNotification = 0;
int humidityThreshold = 60;

BLYNK_WRITE(V0)
{
  //reads the slider value when it changes in the app
  humidityThreshold = param.asInt();
}

void sendPrediction() {

  avg = sum /  count ;

  Blynk.virtualWrite(V1, t);
  Blynk.virtualWrite(V2, h);
  Blynk.virtualWrite(V3, a);
  Blynk.virtualWrite(V4, avg);

  sum = 0;
  count = 0;


  Serial.printf("humidityThreshold=%d\n", humidityThreshold);
  Serial.printf("T=%d H=%d IAQ=%d P=%d S=%d\n", t, h, a, p, s);

  if (h > humidityThreshold ) {

    if (lastNotification == 0 || (millis() - lastNotification) > 60 * 60 * 1000) {
      lastNotification = millis();
      Blynk.notify("Basement is too humid. Check the dehumidifier");
    }

  }

  if (a > 200 ) {

    Blynk.notify("Basement IAQ is bad.");

  }

}


void renderSensorDataOnScreen() {

  //Setting temperature
  spr.createSprite(100, 30);
  spr.fillSprite(TFT_BLACK);
  spr.setTextColor(TFT_LIGHTGREY);
  spr.setTextSize(3);
  spr.drawNumber(t, 5, 5);
  spr.drawString("F", 45, 5);
  spr.pushSprite(35, 80);
  spr.deleteSprite();


  //Setting humidity
  spr.createSprite(100, 30);
  spr.fillSprite(TFT_BLACK);
  spr.setTextColor(TFT_LIGHTGREY);
  spr.setTextSize(3);
  spr.drawNumber(h, 5, 5);
  spr.drawString("%", 45, 5);
  spr.pushSprite(35, 160);
  spr.deleteSprite();



  //IAQ
  String iaqLabel = "Good";

  spr.createSprite(150, 50);
  spr.fillSprite(TFT_BLACK);
  spr.setTextColor(TFT_LIGHTGREY);
  spr.setTextSize(3);


  if (a <= 50) {
    iaqLabel = "Good";
    spr.setTextColor(TFT_DARKGREEN);
  } else if (a > 50 && a <= 100) {
    spr.setTextColor(TFT_ORANGE);
    iaqLabel = "Moderate";
  } else if (a > 100 && a <= 200) {
    spr.setTextColor(TFT_RED);
    iaqLabel = "Unhealthy";
  } else if (a > 200 && a <= 300) {
    spr.setTextColor(TFT_PURPLE);
    spr.setTextSize(2);
    iaqLabel = "Very Unhealthy";
  } else {
    spr.setTextColor(TFT_MAROON);
    spr.setTextSize(2);
    iaqLabel = "Hazardous";
  }

  spr.drawString(iaqLabel, 5, 5);
  spr.setTextColor(TFT_LIGHTGREY);
  spr.setTextSize(2);
  spr.drawNumber(a, 110, 30);
  spr.pushSprite(165, 80);
  spr.deleteSprite();

  //Setting prediction
  spr.createSprite(150, 30);
  spr.fillSprite(TFT_BLACK);
  spr.setTextColor(TFT_LIGHTGREY);
  spr.setTextSize(3);
  spr.drawNumber(avg, 5, 5);
  spr.pushSprite(165, 160);
  spr.deleteSprite();



}
/**
   @brief      Arduino main function. Runs the inferencing loop.
*/


void loop()
{

  s = analogRead(WIO_MIC);
  sum += s;
  count++;

  Blynk.run();
  timer.run();

  if (iaqSensor.run()) { // If new data is available

    t = (int) iaqSensor.temperature * 1.8 + 32;
    h =  iaqSensor.humidity;
    a = iaqSensor.iaq;
    p = (int) (iaqSensor.pressure / 100);


  } else {
    checkIaqSensorStatus();
  }

  renderSensorDataOnScreen();

  if ( millis() > WIO_RESET_INTERVAL_IN_MINUTES * 60 * 1000) {
    NVIC_SystemReset();
  }



}

#define BLYNK_PRINT Serial

/* Includes ---------------------------------------------------------------- */
#include <rpcWiFi.h>
#include <WiFiClient.h>
#include <BlynkSimpleWioTerminal.h>
#include <TFT_eSPI.h> //TFT LCD library 
#include <bsec.h>


#include <dehumidifier_inferencing.h>

int predicted_label = 1;
float prediction_threshold = 0.6;
int prediction_count = 0;
int prediction_sum = 0;
String unitStatus = "STAND BY";

/** Audio buffers, pointers and selectors */
typedef struct {
  int16_t *buffer;
  uint8_t buf_ready;
  uint32_t buf_count;
  uint32_t n_samples;
} inference_t;

static inference_t inference;
static signed short sampleBuffer[2048];
unsigned int sampling_period_us = round(600000 * (1.0 / 16000));
static bool debug_nn = false; // Set this to true to see e.g. features generated from the raw signal



char auth[] = "blynk_token";
char ssid[] = "ssid";
char pass[] = "password";
BlynkTimer timer;



TFT_eSPI tft; //Initializing TFT LCD
TFT_eSprite spr = TFT_eSprite(&tft); //Initializing buffer
Bsec iaqSensor;
String output;
void checkIaqSensorStatus(void);

int t = 0, h = 0, a = 0, p = 0, s = 0, avg = 0;
int sum = 0; int count = 0;

long WIO_RESET_INTERVAL_IN_MINUTES = 60;


/**
   @brief      Arduino setup function
*/
void setup()
{
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(WIO_MIC, INPUT);

  tft.begin(); //Start TFT LCD
  tft.setRotation(3); //Set TFT LCD rotation

  tft.setTextSize(2);
  tft.fillScreen(TFT_BLACK);
  tft.drawString("Connecting to Blynk...", 20, 120);

  Blynk.begin(auth, ssid, pass);
  timer.setInterval(10000L, sendPrediction);
  Blynk.syncAll();

  tft.fillScreen(TFT_BLACK);

  //Setting the title header
  //tft.fillScreen(TFT_WHITE); //Fill background with white color
  tft.fillRect(0, 0, 320, 50, TFT_YELLOW); //Rectangle fill with dark green
  tft.setTextColor(TFT_BLACK); //Setting text color
  tft.setTextSize(3); //Setting text size
  tft.drawString("Basement", 50, 10); //Drawing a text string



  tft.drawFastVLine(150, 50, 160, TFT_DARKGREEN); //Drawing verticle line
  tft.drawFastHLine(0, 130, 320, TFT_DARKGREEN); //Drawing horizontal line
  tft.drawFastHLine(0, 210, 320, TFT_DARKGREEN); //Drawing horizontal line 2

  tft.setTextColor(TFT_LIGHTGREY);
  tft.setTextSize(1);
  tft.drawString("Temperature", 10, 60);

  tft.setTextSize(1);
  tft.drawString("Humidity", 10, 140);

  tft.setTextSize(1);
  tft.drawString("IAQ", 160, 60);

  tft.setTextSize(1);
  tft.drawString("Pressure", 160, 140);



  Wire.begin();
  iaqSensor.begin(BME680_I2C_ADDR_SECONDARY, Wire);
  checkIaqSensorStatus();
  bsec_virtual_sensor_t sensorList[10] = {
    BSEC_OUTPUT_RAW_TEMPERATURE,
    BSEC_OUTPUT_RAW_PRESSURE,
    BSEC_OUTPUT_RAW_HUMIDITY,
    BSEC_OUTPUT_RAW_GAS,
    BSEC_OUTPUT_IAQ,
    BSEC_OUTPUT_SENSOR_HEAT_COMPENSATED_TEMPERATURE,
    BSEC_OUTPUT_SENSOR_HEAT_COMPENSATED_HUMIDITY,
  };

  iaqSensor.updateSubscription(sensorList, 7, BSEC_SAMPLE_RATE_LP);
  checkIaqSensorStatus();

   // summary of inferencing settings (from model_metadata.h)
  ei_printf("Inferencing settings:\n");
  ei_printf("\tInterval: %.2f ms.\n", (float)EI_CLASSIFIER_INTERVAL_MS);
  ei_printf("\tFrame size: %d\n", EI_CLASSIFIER_DSP_INPUT_FRAME_SIZE);
  ei_printf("\tSample length: %d ms.\n", EI_CLASSIFIER_RAW_SAMPLE_COUNT / 16);
  ei_printf("\tNo. of classes: %d\n", sizeof(ei_classifier_inferencing_categories) / sizeof(ei_classifier_inferencing_categories[0]));

  if (microphone_inference_start(EI_CLASSIFIER_RAW_SAMPLE_COUNT) == false) {
    ei_printf("ERR: Failed to setup audio sampling\r\n");
    return;
  }

}

void checkIaqSensorStatus(void)
{
  if (iaqSensor.status != BSEC_OK) {
    if (iaqSensor.status < BSEC_OK) {
      output = "BSEC error code : " + String(iaqSensor.status);
      Serial.println(output);
      while (true) {

      }

    } else {
      output = "BSEC warning code : " + String(iaqSensor.status);
      Serial.println(output);
    }
  }

  if (iaqSensor.bme680Status != BME680_OK) {
    if (iaqSensor.bme680Status < BME680_OK) {
      output = "BME680 error code : " + String(iaqSensor.bme680Status);
      Serial.println(output);
      while (true) {

      }
    } else {
      output = "BME680 warning code : " + String(iaqSensor.bme680Status);
      Serial.println(output);
    }
  }
}

long lastNotification = 0;
int humidityThreshold = 60;

BLYNK_WRITE(V0)
{
  //reads the slider value when it changes in the app
  humidityThreshold = param.asInt();
}

void sendPrediction() {

  float avg = (float)prediction_sum / (float) prediction_count ;
  if ( avg  < 0.5) {
    unitStatus = "RUNNING";
  } else {
    unitStatus = "STAND BY";
  }
  prediction_sum = 0;
  prediction_count = 0;
  Blynk.virtualWrite(V5, unitStatus);
  //V0 used for humidityThreshold
  Blynk.virtualWrite(V1, t);
  Blynk.virtualWrite(V2, h);
  Blynk.virtualWrite(V3, a);
  Blynk.virtualWrite(V4, p);

//  sum = 0;
//  count = 0;


  Serial.printf("humidityThreshold=%d\n", humidityThreshold);
  Serial.printf("T=%d H=%d IAQ=%d P=%d S=%d P=%s\n", t, h, a, p, s, unitStatus.c_str());

  if (h > humidityThreshold ) {

    if (lastNotification == 0 || (millis() - lastNotification) > 60 * 60 * 1000) {
      lastNotification = millis();
      Blynk.notify("Basement is too humid. Check the dehumidifier");
    }

  }

  if (a > 200 ) {

    Blynk.notify("Basement IAQ is bad.");

  }

  

}


void renderSensorDataOnScreen() {

  //Setting temperature
  spr.createSprite(100, 30);
  spr.fillSprite(TFT_BLACK);
  spr.setTextColor(TFT_LIGHTGREY);
  spr.setTextSize(3);
  spr.drawNumber(t, 5, 5);
  spr.drawString("F", 45, 5);
  spr.pushSprite(35, 80);
  spr.deleteSprite();


  //Setting humidity
  spr.createSprite(100, 30);
  spr.fillSprite(TFT_BLACK);
  spr.setTextColor(TFT_LIGHTGREY);
  spr.setTextSize(3);
  spr.drawNumber(h, 5, 5);
  spr.drawString("%", 45, 5);
  spr.pushSprite(35, 160);
  spr.deleteSprite();



  //IAQ
  String iaqLabel = "Good";

  spr.createSprite(150, 50);
  spr.fillSprite(TFT_BLACK);
  spr.setTextColor(TFT_LIGHTGREY);
  spr.setTextSize(3);


  if (a <= 50) {
    iaqLabel = "Good";
    spr.setTextColor(TFT_DARKGREEN);
  } else if (a > 50 && a <= 100) {
    spr.setTextColor(TFT_ORANGE);
    iaqLabel = "Moderate";
  } else if (a > 100 && a <= 200) {
    spr.setTextColor(TFT_RED);
    iaqLabel = "Unhealthy";
  } else if (a > 200 && a <= 300) {
    spr.setTextColor(TFT_PURPLE);
    spr.setTextSize(2);
    iaqLabel = "Very Unhealthy";
  } else {
    spr.setTextColor(TFT_MAROON);
    spr.setTextSize(2);
    iaqLabel = "Hazardous";
  }

  spr.drawString(iaqLabel, 5, 5);
  spr.setTextColor(TFT_LIGHTGREY);
  spr.setTextSize(2);
  spr.drawNumber(a, 110, 30);
  spr.pushSprite(165, 80);
  spr.deleteSprite();

  //Setting prediction
  spr.createSprite(150, 30);
  spr.fillSprite(TFT_BLACK);
  spr.setTextColor(TFT_LIGHTGREY);
  spr.setTextSize(3);
  //spr.drawNumber(avg, 5, 5);
  spr.drawString(unitStatus.c_str(),5,5);
  spr.pushSprite(165, 160);
  spr.deleteSprite();



}
/**
   @brief      Arduino main function. Runs the inferencing loop.
*/


void loop()
{

//  s = analogRead(WIO_MIC);
//  sum += s;
//  count++;

  Blynk.run();
  timer.run();

  if (iaqSensor.run()) { // If new data is available

    t = (int) iaqSensor.temperature * 1.8 + 32;
    h =  iaqSensor.humidity;
    a = iaqSensor.iaq;
    p = (int) (iaqSensor.pressure / 100);


  } else {
    checkIaqSensorStatus();
  }


  ei_printf("Recording...\n");

  bool m = microphone_inference_record();
  if (!m) {
    ei_printf("ERR: Failed to record audio...\n");
    return;
  }

  ei_printf("Recording done\n");

  signal_t signal;
  signal.total_length = EI_CLASSIFIER_RAW_SAMPLE_COUNT;
  signal.get_data = &microphone_audio_signal_get_data;
  ei_impulse_result_t result = { 0 };

  EI_IMPULSE_ERROR r = run_classifier(&signal, &result, debug_nn);
  if (r != EI_IMPULSE_OK) {
    ei_printf("ERR: Failed to run classifier (%d)\n", r);
    return;
  }

  // print the predictions
  float max_prediction = 0;
  ei_printf("Predictions ");
  ei_printf("(DSP: %d ms., Classification: %d ms., Anomaly: %d ms.)",
            result.timing.dsp, result.timing.classification, result.timing.anomaly);
  ei_printf(": \n");
  for (size_t ix = 0; ix < EI_CLASSIFIER_LABEL_COUNT; ix++) {
    ei_printf("    %s: %.5f\n", result.classification[ix].label, result.classification[ix].value);
    if ( result.classification[ix].value >= max_prediction) {
      max_prediction = result.classification[ix].value;
      predicted_label = ix;
    }

  }

  if (max_prediction >= prediction_threshold) {
    ei_printf("Predicted activity = %d with score=%.5f (0= Running, 1= Standby)\n", predicted_label, max_prediction);
    prediction_count = prediction_count + 1;
    prediction_sum = prediction_sum + predicted_label;

  }
  renderSensorDataOnScreen();

  if ( millis() > WIO_RESET_INTERVAL_IN_MINUTES * 60 * 1000) {
    NVIC_SystemReset();
  }



}


/**
   @brief      Printf function uses vsnprintf and output using Arduino Serial

   @param[in]  format     Variable argument list
*/
void ei_printf(const char *format, ...) {
  static char print_buf[1024] = { 0 };

  va_list args;
  va_start(args, format);
  int r = vsnprintf(print_buf, sizeof(print_buf), format, args);
  va_end(args);

  if (r > 0) {
    Serial.write(print_buf);
  }
}


/**
   @brief      Init inferencing struct and setup/start PDM

   @param[in]  n_samples  The n samples

   @return     { description_of_the_return_value }
*/
static bool microphone_inference_start(uint32_t n_samples)
{
  inference.buffer = (int16_t *)malloc(n_samples * sizeof(int16_t));

  if (inference.buffer == NULL) {
    return false;
  }

  inference.buf_count  = 0;
  inference.n_samples  = n_samples;
  inference.buf_ready  = 0;
  

  return true;
}

/**
   @brief      Wait on new data

   @return     True when finished
*/
static bool microphone_inference_record(void)
{
  inference.buf_ready = 0;
  inference.buf_count = 0;

  if (inference.buf_ready == 0) {
    for (int i = 0; i < 8001; i++) {
      inference.buffer[inference.buf_count++] = map(analogRead(WIO_MIC), 0, 1023, -32768, 32767);
      delayMicroseconds(sampling_period_us);

      if (inference.buf_count >= inference.n_samples) {
        inference.buf_count = 0;
        inference.buf_ready = 1;
        break;
      }
    }
  }

  return true;
}

/**
   Get raw audio signal data
*/
static int microphone_audio_signal_get_data(size_t offset, size_t length, float *out_ptr)
{
  numpy::int16_to_float(&inference.buffer[offset], out_ptr, length);

  return 0;
}

/**
   @brief      Stop PDM and release buffers
*/
static void microphone_inference_end(void)
{
  free(inference.buffer);
}

#if !defined(EI_CLASSIFIER_SENSOR) || EI_CLASSIFIER_SENSOR != EI_CLASSIFIER_SENSOR_MICROPHONE
#error "Invalid model for current sensor."
#endif

Credits

Mithun Das

34 projects • 180 followers

Hacker and Maker driven by passion. Ambassador at Edge Impulse and Balena. Follow me on Twitter @_mithundas

Basement Monitoring Using Wio Terminal and Blynk

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Motivation

Solution

Air Quality Monitoring

Blynk Dashboard

How To Integrate Wio Terminal With Blynk

Final Product In Action

Unit Status Prediction

Circuit Diagram

Custom parts and enclosures

wio_he0t50dwCi.stl

Schematics

img_4473_ZX2szCAeFw.jpg

Code

dehumidifier.ino

dehumidifier_inferencing.zip

dehumidifier_tinyml.ino

Credits

Mithun Das

Comments

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Basement Monitoring Using Wio Terminal and Blynk

Basement Monitoring Using Wio Terminal and Blynk

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Motivation

Solution

Air Quality Monitoring

Blynk Dashboard

How To Integrate Wio Terminal With Blynk

Final Product In Action

Unit Status Prediction

Circuit Diagram

Custom parts and enclosures

wio_he0t50dwCi.stl

Schematics

img_4473_ZX2szCAeFw.jpg

Code

dehumidifier.ino

dehumidifier_inferencing.zip

dehumidifier_tinyml.ino

Credits

Mithun Das

Comments

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