Bug or limitation in HTTPClient

Projects Networking, Protocols, and Devices
1

Hi,

I am still quite new here.... :confused:

Using ESP8266, Arduino 1.8.10 and the Libary from github

I have observed a problem at least with some HTTPClient.h Libaries

Code: (no compliation error ... and it works for some http get operations)

//HUEcommand contains a correct statement to request from 
 //my HUE Bridge the basic configuration as answer

 http.begin(HUEcommand);
 int httpCode = http.GET();
 if (httpCode == 200) { // I receive here the correct Http Code "200"
   Serial.println(HUEcommand);
   String HUEanswer = http.getString();

With the last statement I get a crash and a stack output. But not all the time .... if I request less data from my HUE bridge with other GET commands I dont have a problem. As far as I could figure out it is related to the length of the answer string and that is very long for the "config" request. I have fixed the problem for me by avoiding using HTTPClient.h for this by directly reading the answer as stream with:

client.findUntil("\"localtime\":\"", "\0");

I am not sure if this problem is valid for all HTTPClient.h or just a specific version ..... because sometimes I had a problem ...sometimes not and I have confused my local Arduino IDE with different Libaries from different sources.

Best Regards
Michael

2

Please READ THIS POST to help you get the best out of the forum.

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These steps may also save you some unnecessary time and effort in the forum.

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  • Where possible use USB 2.0 ports or a USB 2.0 POWERED HUB to rule out USB 3.0 issues.

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Performing the above actions may help resolve your problem without further help.

Bob.

3

Hi,

not sure why I got the comment above.

I cleaned up my Arduino installation. Now I know a bit better which Libaries I use. It is the newest package 2.6.1. and can be found here:

Also my HTTPClient is from there -> And it creates the problem described above!

Exception (3):
epc1=0x401009a0 epc2=0x00000000 epc3=0x00000000 excvaddr=0x4002b909 depc=0x00000000

stack>>>

ctx: cont
sp: 3ffffaf0 end: 3fffffc0 offset: 01a0
3ffffc90: 3fff1900 3fff1728 3fff0360 40218188
3ffffca0: 00000000 00000000 0000001f 00000050
3ffffcb0: 0000005c 00000046 00000020 40100b90
3ffffcc0: 00000006 3fff02e0 00000022 0058bb23
3ffffcd0: 4020f3dd 00000030 00000014 40218c84
3ffffce0: 3fff1728 3fff18bc 3fff1724 40212bc8
3ffffcf0: 3fff0360 00000000 00000000 001b9ddc

.........

Also with the complete example from here:

"ESP8266: HTTP GET Requests - techtutorialsx"

I get a crash with the Http Get request:

"http://HUE_IP_adress/api/HUE_User_ID/config"

Limitation or bug? Workaround?

I am still confused that it worked for some time .... but I can not find out which versions of libaries I have used.

Best Regards
Michael