ESP8266 Community Forum

- Sun Jul 22, 2018 8:01 am #77332 Following on from my Pi sleep/lock problem I have followed the advice of another user to cut out the pi from my process.

I have had a few problems but am getting the code written slowly and have a question about sending the contents of the spiff file to my PC. I might look at the MQTT? alternative protocol later but want to stick with udp at the moment.

The code I have for reading the content of the spiffs file and displaying it is below and works but how do I then make the file contents into something that can be transmitted wirelessly to my network?

Example line from the spiffs file: 1532206976, 29.1, 37.0,1008.4

My original code just sending one line of data which worked:

Code: Select all int packetSize = udp.parsePacket();
  if (packetSize)
  {
    // receive incoming UDP packets
    Serial.printf("Received %d bytes from %s, port %d\n", packetSize, udp.remoteIP().toString().c_str(), udp.remotePort());
    int len = udp.read(incomingPacket, 255);
    if (len > 0)
    {
      incomingPacket[len] = 0;
    }
    Serial.printf("UDP packet contents: %s\n", incomingPacket);
    getWeather(); // Function to get the temperature and humidity
    // send back a reply, to the IP address and port we got the packet from
    udp.beginPacket(udp.remoteIP(), udp.remotePort());
    udp.write(outputData);
    udp.endPacket();

// Function pasted here for reference
void getWeather() {
    h = bme.readHumidity();
    t = bme.readTemperature();   
    p = (bme.readPressure() / 100.0F);
    dtostrf(t, 5, 1, temperatureFString);
    dtostrf(h, 5, 1, humidityString);
    dtostrf(p, 6, 1, pressureString);
    sprintf(outputData, "%s,%s,%s", temperatureFString, humidityString, pressureString);   
    delay(100);
    Serial.println(t);
}


New code that reads the previously saved data from spiffs and could be any length up to 1 mB
Need to format the Serial.print into something I can transmit in udp.write() ?

Code: Select allint i;
 
  int packetSize = udp.parsePacket();
  //if (packetSize)
  if ((packetSize) && (download == 0)) // Make sure the data is only transmitted the once in this loop
  {
    // receive incoming UDP packets
    Serial.printf("Received %d bytes from %s, port %d\n", packetSize, udp.remoteIP().toString().c_str(), udp.remotePort());
    int len = udp.read(incomingPacket, 255);
    if (len > 0)
    {
      incomingPacket[len] = 0;
    }
    Serial.printf("UDP packet contents: %s\n", incomingPacket);

// If file requested run this code and transmit the data
// open file for reading
File  f = SPIFFS.open("/fileName.txt", "r");
if (!f) {
  Serial.println("file open failed");
         }
Serial.println("====== Reading file =======");
for(i=0; i<f.size(); i++) //Read upto complete file size
  {
  Serial.print((char)f.read());
  }     
  f.close();  //Close file
  Serial.println();
  Serial.println("File Closed");   
  // Run this after the file has been uploaded to clear the memory
  //Delete file WORKS
  //SPIFFS.remove("/fileName.txt");

    // send back a reply, to the IP address and port we got the packet from
    udp.beginPacket(udp.remoteIP(), udp.remotePort());
    udp.write(outputData);
    udp.endPacket();

download = 1;
  }