ESP8266 Community Forum

- Tue Jul 03, 2018 10:31 am #76841 Hi.

My application sends some data to thingspeak.
After about one hour I usually have a crash.

Tracing the heap memory with this code :

Code: Select all         
printf("Free Heap before write: %d\n", ESP.getFreeHeap());
ThingSpeak.writeFields(IdTS[ch], APIKey_CH[ch]));
printf("Free Heap after write: %d\n", ESP.getFreeHeap());


Output :

Code: Select allFree Heap before write: 17856
Free Heap after write: 17800
Free Heap before write: 17800
Free Heap after write: 17744
Free Heap before write: 17744
Free Heap after write: 17688
Free Heap before write: 17688
Free Heap after write: 17632
Free Heap before write: 17632
Free Heap after write: 17576
Free Heap before write: 17576
Free Heap after write: 17520


So I loose 56 bytes in the heap at each call of ThingSpeak.writeFields

In my previous version I did not use the ThingSpeak lib, and directly called

Code: Select allclient.connect("api.thingspeak.com", 80)
client.print("....")


And I had same kind of crash.

So my feeling is that the issue is in the wifi lib.

Any idea on the subject?

Thanks

- Tue Jul 03, 2018 11:39 am #76845 Known problem with 2.4.1

https://github.com/esp8266/Arduino/issues/4497

t has been fixed but not in a released version.

One either needs to use the Git version or extract the WifiClient.cpp from Git and replace that file in your dev tree.

- Tue Jul 03, 2018 11:46 am #76846 Yes, I just was googling and found the link ...
Thanks

Chris

- Tue Jul 03, 2018 11:51 am #76847 Reverting to 2.3.0

Much better

Code: Select allFree Heap : 17104
Free Heap before write: 17104
Free Heap after write: 17104
Free Heap before write: 17104
Free Heap after write: 17104
Free Heap before write: 17104
Free Heap after write: 17104
Free Heap before write: 17104
Free Heap after write: 17104
Free Heap before write: 17104