void Task1code( void * pvParameters ) {
 Serial.print("Collection task running on core ");
 Serial.println(xPortGetCoreID());
 //local JsonDocument, initialzing here can uses PSRAM
 SpiRamJsonDocument group_data1(DOCSIZE); 
 SpiRamJsonDocument group_data2(DOCSIZE); 
 JsonArray object;
 //using global varible to store the reference for these two JsonDocuments
 //and process them in Task2
 holder1 = &group_data1;
 holder2 = &group_data2;
 Serial.println((String)"Memory available in PSRAM : " +ESP.getFreePsram());
 for(;;){
 if(digitalRead(SWITCH_PIN) != HIGH) {
 vTaskDelay(1); //feeding the dog
 continue;
 }
 //buffer switching 
 if(!processing) {
 if(task1docInit && !task2docInit){
 Serial.println("Creating group data1");
 object = group_data1.createNestedArray("group_data"); //initialized here
 } else if(!task1docInit && task2docInit) {
 Serial.println("Creating group data2");
 object = group_data2.createNestedArray("group_data"); //initialized here
 
 }
 processing = true;
 }
 delay(5); //simulating collecting samples in 500Hz for ADXL355
 //simulation parameters
 float x_pos = (float)random(0,25);
 float y_pos = (float)random(0,25);
 float x_act = x_pos * random(0,2);
 float y_act = y_pos * random(0,2);
 
 //fill the documents
 if(counter <= 900){ 
 //to avoid buffer overflow, once it reach the limit, we need to stop to wait
 JsonObject object_in = object.createNestedObject();
 object_in["Machine_ID"] = ID;
 object_in["Job_ID"] = job_id;
 object_in["Job_order"] = job_order;
 object_in["Layer"] = layer;
 object_in["X_pos"] = x_pos;
 object_in["Y_pos"] = y_pos;
 object_in["X_act"] = x_act;
 object_in["Y_act"] = y_act;
 if(job_order % 10 == 0){
 layer++;
 //job_order = 1;
 } 
 job_order++;
 if(layer == 1000){
 job_id++;
 layer = 1;
 } 
 counter++; 
 }
 
 //TODO: determine what is the proper size for job_order to collect
 if(counter >= 500 && ready) {
 //Serial.println("reaching here 2");
 Serial.println((String)"Collecting done! counter: " + counter);
 //Serial.println(ESP.getFreePsram());
 processing = false; 
 counter = 0;
 ready = false;
 if(task1docInit && !task2docInit){
 // serializeJson(group_data1, Serial);
 Serial.println();
 sending = true;
 buffer_index = 1;
 task1docInit = false;
 task2docInit = true;
 } else if(!task1docInit && task2docInit){
 // serializeJson(group_data2, Serial);
 Serial.println();
 sending = true;
 buffer_index = 2;
 task1docInit = true;
 task2docInit = false;
 } 
 //rest of them give to task2 to deal with
 }
 }
}

void Task2code( void * pvParameters ) {
 Serial.print("Task2 running on core ");
 Serial.println(xPortGetCoreID());
 char* toSend = (char*)heap_caps_malloc(DOCSIZE * sizeof(char), MALLOC_CAP_SPIRAM);
 //char* toSend = (char*)ps_malloc(DOCSIZE * sizeof(char));
 char* printtext = (char*)malloc(16 * sizeof(char)); 
 for(;;){
 if(digitalRead(SWITCH_PIN) != HIGH){
 vTaskDelay(1);
 continue;
 }
 if(!processing && sending) {
 //if processing is false, and sending is true, then we need to send buffer to cloud
 // determining Which buffer will be sent
 switch(buffer_index){
 case 1:
 printtext = (char*)"Sending 1...";
 Serial.println(printtext);
 serializeJson((*holder1), toSend, DOCSIZE * sizeof(char));
 break;
 case 2:
 printtext = (char*)"Sending 2...";
 Serial.println(printtext);
 serializeJson((*holder2), toSend, DOCSIZE * sizeof(char));
 break;
 }
 // I have no idea why HTTP request crash the ram or stack
 //I have tested the hardware, indicating the PSRAM is working properly
 //I replace this HTTP post request as delay(500) to simulate request time, and no watchdog is trigged. 
 //But when I use this HTTP POST, memory corruption is happening.
 //Sometimes the crash happens at the beginning of the process and sometimes wait for a long time
 if(http.POST(toSend)>0) {
 //Serial.println(http.getString());
 http.clearAllCookies();
 http.clear(); 
 }
 //delay(500); //simulate http request time
 //Cleaning process
 printtext = (char*)"Cleaning";
 Serial.println(printtext);
 switch(buffer_index){
 case 1:
 (*holder1).clear();
 break;
 case 2:
 (*holder2).clear();
 break; 
 }
 buffer_index = 0;
 sending = false;
 ready = true;
 } 
 } 
}