Thingsboard serialize json data issue

[gittimotap]

Describe the bug
thingsboard/thingsboard#10164

Troubleshooter report
Here is the report generated by the ArduinoJson Troubleshooter:
[Paste the report here]

Environment
Here is the environment that I used:

• Microcontroller: https://wiki.dfrobot.com/FireBeetle_Board_ESP32_E_SKU_DFR0654
• Core/runtime: ESP32 core for Arduino 2.0.14 [e.g. ESP8266 core for Arduino v3.0.2]
• IDE: Arduino IDE 2.0.3

Reproduction
Here is a small snippet that reproduces the issue.

JsonDocument doc;

DeserializationError error = deserializeJson(doc, "{\"hello\":\"world\"}");

[insert repro code here]
https://github.com/thingsboard/thingsboard-client-sdk/blob/master/examples/0003-esp8266_esp32_send_data/0003-esp8266_esp32_send_data.ino

**Compiler output**    
If relevant, include the complete compiler output (i.e. not just the line that contains the error.)

**Program output**  
If relevant, include the repro program output.
16:59:57.275 -> .Connected to AP
16:59:58.286 -> Connecting to: (demo.thingsboard.io) with token (xxxxx)
16:59:58.493 -> Sending temperature data...
16:59:58.493 -> [TB] Unable to serialize json data
16:59:58.493 -> Sending humidity data...
16:59:58.493 -> [TB] Unable to serialize json data
16:59:59.496 -> Sending temperature data...
16:59:59.496 -> [TB] Unable to serialize json data
16:59:59.496 -> Sending humidity data...
16:59:59.496 -> [TB] Unable to serialize json data
17:00:00.466 -> Sending temperature data...
17:00:00.466 -> [TB] Unable to serialize json data

Expected output:

[insert expected output here]

Actual output:

[insert actual output here]

[gittimotap]

6.21.5 works, seems like the next release broke something. Found originally here: thingsboard/thingsboard#10164

[bblanchon]

Hi @gittimotap,

I need more information.
Please provide at least a reproduction code.

Best regards,
Benoit

[gittimotap]

Hi Benoit
Easiest way is to take for example this https://github.com/thingsboard/thingsboard-client-sdk/blob/master/examples/0003-esp8266_esp32_send_data/0003-esp8266_esp32_send_data.ino and run it on some Arduino board (I tried both https://wiki.dfrobot.com/SKU_DFR0868_Beetle_ESP32_C3 and https://wiki.dfrobot.com/FireBeetle_Board_ESP32_E_SKU_DFR0654), it will give you an error straight away. You can use demo.thingsboard.io, you can have a free account there.

In any case, I tried multiple of the SDK examples and all give the same error: https://github.com/thingsboard/thingsboard-client-sdk/tree/master/examples (ESP32 based, not ESP8266). I always get "[TB] Unable to serialize json data" with anything above 6.21.5.

Regards
Timo

[bblanchon]

The workaround is available in ArduinoJson 7.0.4.