#include <ArduinoJson.h>

int knockSensor0 = 7;  

int val0 = 0;

void setup() {
  pinMode(knockSensor0, INPUT);
  // put your setup code here, to run once:
  
  Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
  val0 = digitalRead(knockSensor0);    

  // Create the JSON document
  const size_t capacity = JSON_OBJECT_SIZE(48);
  DynamicJsonDocument doc(capacity);

  doc["val0"] = val0; // 100

  //Send data to NodeMCU
  serializeJson(doc, Serial);
}