UDP will not send until it has received at least one packet #1802

jgrina · 2016-03-21T15:43:56Z

Basic Infos

Hardware

Hardware: Adafruit Huzzah, NodeMCU, Adafruit Feather
Core Version: 2.1

Description

Why does udp sendPacket wait for a received packet before sending? It is only the first send command that waits. If I force a transmit from host, a burst of "sent" packets appears and everything works great from there. Sends and receives go. I'm using Arduino IDE version 1.6.8 on a Win 7 machine for this listing, but the same happened with version 1.6.5 on my Win 10 machine. The ESP is an Adafruit Huzzah breakout board, but I also tried the ESP feather 8266 and the NodeMCU boards with the same result. I have updated the libraries to the latest code while installing IDE version 1.6.8.

The attached zipfiles are the program, monitor activity from the host and Arduino com port monitor

The arduino side file shows the ESP messages which have the sends, but no response until the host sends "!Start" message. The host side shows no messages until after the !Start message, then a burst of messages with responses to each message.

I've tried several WiFi.modes, plus udp.flush(), udp.stop(), commands, but nothing changes.

With a looping program, this is not a major problem, I can use the monitor send function to start the ESP8266 noodes, but I want to use battery power and deep sleep function for some nodes. Deep sleep erases any knowledge of previous packet receives, so it must receive a packet every time it wakes up.

Host side is Win 7, MegunoLink Pro
I am using the Timer function in MegunoLink to broadcast a "!Start" message every 1/2 second

Jim

Settings in IDE

Module: Huzzah, generic ESP, NodeMCU 1.0
Flash Size: 4Mb
CPU Frequency: 80mhz
Flash Mode: DIO
Flash Frequency: 40Mhz
Upload Using: serial
Reset Method: ck

zipfiles.zip

igrr · 2016-03-21T16:10:49Z

It would be really helpful if you could post the sketch which may be used to reproduce this issue!

igrr · 2016-03-21T16:12:07Z

For the record, i think UDP should be able to send packets first. You can check NTPClient sample for the demonstration of it.

jgrina · 2016-03-21T21:55:06Z

Igrr, I attached the sketch file and the output from both the host and ESP. They are at the end of the post "zipfiles.zip". The NTPclient first uses DNS to get the IP address of the .gov server. I can try that, but not send the UDP request to time server. I'll see if that works. However, I was trying to design a UDP based program which wakes up, sends the data and goes back into deep sleep. Deep sleep is important for battery life. Depending on the amount of time awake vs asleep, It could make a battery last 60 times as long with sleep mode. I'll get back to you about using the Time Server to wake up UDP sends.

pipi61 · 2016-03-21T22:25:04Z

Hi!
this example not a NTP sample...
try after sendPacket(statusUpdate); long time delay...
try:
current_millis = millis();
// delay(1000);
// int cb = UDPNTPClient.parsePacket();
wcnt = 0;
while((cb = UDPNTPClient.parsePacket()) == 0) //wait for ntp packet
{
delay(1);
Serial.print("*");
wcnt++;
if(wcnt > 1000)
break;
}
ntp_respond_millis = millis() - current_millis;

if(!cb)
    {
      Serial.println("NTP no packet yet");
ntpnextupdate=10*1000+millis(); //10sec        ntpserverptr++;

    }
else
    {
      Serial.print("NTP packet received, response=");
      Serial.print(ntp_respond_millis);
      Serial.print("msec, length=");
      Serial.println(cb);
      UDPNTPClient.read(packetBuffer, NTP_PACKET_SIZE); // read the packet into the buffer 

      .......
      }

jgrina · 2016-03-21T23:01:44Z

I tried the UDP timeserver, with a small modification. I ran the time server, got a valid IP for server and used the IP address of the server.-

//get a random server from the pool
// WiFi.hostByName(ntpServerName, timeServerIP);
IPAddress timeServerIP(24,56,178,123);
sendNTPpacket(timeServerIP); // send an NTP packet to a time server

The result was a long list like this -

sending NTP packet...
no packet yet

I cannot receive the NTP packet from server, because I have not actually send the packet. If I just change the program to -

//get a random server from the pool
WiFi.hostByName(ntpServerName, timeServerIP);
// IPAddress timeServerIP(24,56,178,123);
sendNTPpacket(timeServerIP); // send an NTP packet to a time server

I get the time with no problem. -

Connecting to Phoenix
......
WiFi connected
IP address:
192.168.1.102
Starting UDP
Local port: 2390
sending NTP packet...
packet received, length=48
Remote host = 128.138.141.172:123
Seconds since Jan 1 1900 = 3667589078
The UTC time is 22:44:38

sending NTP packet...
packet received, length=48
Remote host = 128.138.141.172:123
Seconds since Jan 1 1900 = 3667589109
The UTC time is 22:45:09

Connecting to Phoenix
......
WiFi connected
IP address:
192.168.1.102
Starting UDP
Local port: 2390
sending NTP packet...
packet received, length=48
Remote host = 128.138.141.172:123
Seconds since Jan 1 1900 = 3667589078
The UTC time is 22:44:38

sending NTP packet...
packet received, length=48
Remote host = 128.138.141.172:123
Seconds since Jan 1 1900 = 3667589109
The UTC time is 22:45:09

If I trick the remote host that I'm using for temperature monitoring via UDP, into sending packets to port 2390, I get -

sending NTP packet...
no packet yet

sending NTP packet...
packet received, length=12
Remote host = 192.168.1.105:2881
Seconds since Jan 1 1900 = 0
The UTC time is 6:28:16

Now my temp monitoring host has no idea about time servers, but the IP address is 192.168.1.105.

Jim

I suppose I could include the -
WiFi.hostByName(ntpServerName, timeServerIP);

command in my program. but I don't like the idea. I have 4 operational nodes, and ideas for several more. I don't think having a half dozen nodes asking for ntp server ip's is a good idea.

jgrina · 2016-03-22T00:13:09Z

OK, I reopened. I made a mistake

pipi61 · 2016-03-22T00:23:09Z

Hi!
try network tests program to receive and view sended packet from this page:
http://ruten-proteus.blogspot.hu/2014/12/esp8266-at-command.html

jgrina · 2016-03-22T20:35:33Z

I got SocketTest 3.0.0 and the results were the same as my host program. ESP will not speak unless spoken to. So I'm stuck. I see the problem that I reported is listed as troubleshooting, no milestones and no one assigned to it. Dunno, I'll just wait a few days.

igrr · 2016-03-22T20:58:14Z

Sorry, I haven't noticed the sketch first time i extracted the archive. I loaded the sketch, made the following changes to fit my network environment:

change WiFi mode to WiFi.mode(WIFI_STA);
change network SSID and password
remove WiFi.config call because I have DHCP in my network
changed remoteIpNo to match the IP address of my laptop
added localIpNo = WiFi.localIP(); at the end of setup function

Then fired up nc on my laptop, and saw packets coming in:

[igrokhotkov@igrokhot-mbp ~]$ nc -l -u -p 2881
{UI|SET|StatusM.Text=192.168.1.35}
{UI|SET|StatusM.Text=192.168.1.34}
{UI|SET|StatusM.Text=192.168.1.35}
{UI|SET|StatusM.Text=192.168.1.34}

Output from serial monitor was:

Local port: 2880
*********** start loop **************

Send To 192.168.1.34
{UI|SET|StatusM.Text=192.168.1.35}
No response

Send To 192.168.1.34
{UI|SET|StatusM.Text=192.168.1.34}
No response
****** end loop ****** 
0
*********** start loop **************

Send To 192.168.1.34
{UI|SET|StatusM.Text=192.168.1.35}
No response

Send To 192.168.1.34
{UI|SET|StatusM.Text=192.168.1.34}
No response
****** end loop ****** 
1

and so on.

So unfortunately I'm not able to reproduce this so far.
I thought that the difference might be due to the fact that i removed WiFi.config initially.
So I have put WiFi.config line back, and adjusted localIpNo. Gateway and netmask already matched my network. Loaded the sketch again, and I'm still able to receive packets.

In the end i think the issue you are seeing is due to WiFi.mode(WIFI_AP) line. Given that WiFi.config sets static config for STA mode, and not for AP, your ESP is setting up it's own network, and the IP is most likely 192.168.4.1, which explains why you don't get the data in SocketTest.

jgrina · 2016-03-23T02:42:45Z

Interesting. I just used -
WiFi.hostByName(ntpServerName, timeServerIP);
In my program to start the udp.beginPacket() ... udp.endPacket();
and it works. Even though the hostByName function has nothing to do with the rest of the program, the udp packet that is sent as a response, does activate packet sending. Fascinating! I just need an activation method that doesn't use the NTP function. WiFi.hostByName obviously can send a udp packet, but udp.beginPacket can't. Hmm. I need to see how the hostByName manages to get around the limitation of receive before send. There are a bunch of issues involving broadcast, packet sending, etc. I wonder if they can all use hostByName as a work around.

igrr · 2016-03-23T05:14:07Z

I can confirm that your example also works for me without WiFi.hostByName, once I change WiFi mode to WiFi_STA.

jgrina · 2016-03-23T14:24:40Z

I see that you get it to work. Since you do and I don't, maybe it is the ESP libraries. The library included with IDE version 1.6.8 is ESP8266 builtin by Simmon Peter,Markus Sattler,Ivan Grokhotkov version 1.0.0 ESP8266 sketches examples. I tried to click on the "more info" but nothing happens. I downloaded the zipfile from GitHub but the zip installer in the IDE says it is not a library. I can't find where Arduino installs the ESP8266 libraries. I've used Arduino IDE since version 0019, but the new library manager has managed to make it very difficult to upgrade. I have the .json file for ESP8266 in my preferences, but it seems to think this is the newest release.

igrr · 2016-03-23T14:28:22Z

You can check the core version in Tools > Boards > Boards manager menu, scroll to the end of the list, it should look like this:

Also did you change WiFi.mode call as I have suggested?

jgrina · 2016-03-23T14:33:54Z

I'm looking athe the boards manager and it lloks like this

jgrina · 2016-03-23T14:35:31Z

I went through your changes, made all of them. And yes, I did the Wifi.mode to STA

jgrina · 2016-03-23T14:39:38Z

How do I get the version of ESP8266 that you are using? It wasn't included with the install of IDE version 1.6.8, and it doesn't show up on the updatable list of libraries.

igrr · 2016-03-23T14:43:33Z

You must be looking at library manager, not the boards manager. Boards manager is in Tools > Boards menu.

jgrina · 2016-03-23T14:49:46Z

I used sketch > include library > manage libraries for that snip I sent. Then looked at your instructions again. I went to TOOLS and the upgrade is there. I've upgraded, I think, but I have to go to my daughter's house, three hours away. and I won't be back until Monday.

Arduino: 1.6.8 (Windows 7), Board: "Adafruit HUZZAH ESP8266, 80 MHz, Serial, 115200, 4M (3M SPIFFS)"

Board huzzah (platform esp8266, package esp8266) is unknown

Error compiling for board Adafruit HUZZAH ESP8266.

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.

jgrina · 2016-03-23T14:59:30Z

Oh, yes, I love the new boards manager !@#$%.
OK, you set me on the right path, but the program will no longer compile. I can fix that, I think

jgrina · 2016-03-23T15:12:51Z

igrr · 2016-03-23T15:15:18Z

First you need to remove 2.1.0-rc2, then change URL in preferences to the stable boards manager package url, and then install 2.1.0 version.

jgrina · 2016-03-23T15:16:40Z

However, I might not. Now the wonderful boards manager can't find the board. It shows me the board through the TOOLS menu but the compiler can't compile it.
Arduino: 1.6.8 (Windows 7), Board: "Adafruit HUZZAH ESP8266, 80 MHz, Serial, 115200, 4M (3M SPIFFS)"

Board huzzah (platform esp8266, package esp8266) is unknown

Error compiling for board Adafruit HUZZAH ESP8266.

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.

jgrina · 2016-03-23T15:27:18Z

So, I have the stable version installed, and I closed and reopened ArduinoIDE, but I still get -
Arduino: 1.6.8 (Windows 7), Board: "Adafruit HUZZAH ESP8266, 80 MHz, Serial, 115200, 4M (3M SPIFFS)"

Board huzzah (platform esp8266, package esp8266) is unknown

Error compiling for board Adafruit HUZZAH ESP8266.

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.

Juppit · 2016-03-23T15:40:23Z

Mostly it helps me to rename the folder
C:\Users[user_name]\AppData\Local\Arduino15 in somthing like
Arduino.old and relod it. The preferences.txt must be reloaded.

Am 23.03.2016 um 16:27 schrieb jgrina:

new capture
https://cloud.githubusercontent.com/assets/5010218/13990210/79d53120-f0e1-11e5-9d48-e3de4c799513.PNG
So, I have the stable version installed, and I closed and reopened
ArduinoIDE, but I still get -
Arduino: 1.6.8 (Windows 7), Board: "Adafruit HUZZAH ESP8266, 80 MHz,
Serial, 115200, 4M (3M SPIFFS)"

Board huzzah (platform esp8266, package esp8266) is unknown

Error compiling for board Adafruit HUZZAH ESP8266.

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.

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#1802 (comment)

jgrina · 2016-03-23T15:59:39Z

I have two computers, The test computer is an old Win7, and the main computer is Win10. I went to the Win10 machine and loaded the ESP community version 2.1.0 I think this works. It has IDE version 1.6.5 on it. The program compiles and runs. It does not appear to need a awake up packet. I'd like to close this issue and straighten out the IDE version 1.6.8.

Thanks,
Jim

igrr added the type: troubleshooting label Mar 21, 2016

jgrina closed this as completed Mar 21, 2016

jgrina reopened this Mar 22, 2016

jgrina closed this as completed Mar 27, 2016

krzychb mentioned this issue Aug 27, 2016

New FAQ - How to resolve "Board generic (platform esp8266, package esp8266) is unknown" error? #2444

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UDP will not send until it has received at least one packet #1802

UDP will not send until it has received at least one packet #1802

jgrina commented Mar 21, 2016

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UDP will not send until it has received at least one packet #1802

UDP will not send until it has received at least one packet #1802

Comments

jgrina commented Mar 21, 2016

Basic Infos

Hardware

Description

Settings in IDE

igrr commented Mar 21, 2016

igrr commented Mar 21, 2016

jgrina commented Mar 21, 2016

pipi61 commented Mar 21, 2016

jgrina commented Mar 21, 2016

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igrr commented Mar 22, 2016

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