FAQ
This page covers ArduinoJson 5.13.5, consider upgrading to version 6.21.2.
Common
-
How to reuse a
JsonBuffer
?★★★★ -
What are the differences between
StaticJsonBuffer
andDynamicJsonBuffer
?★★ - What's the best way to use the library?★★
- How to determine the buffer size?★★
-
Why shouldn't I use a global
JsonBuffer
?★ - How to reduce memory usage?★
- Why does my device crash or reboot?
- What are the common sizes for JsonBuffer?
- I found a memory leak in the library!
-
How to assign a
JsonArray
orJsonObject
? -
How to write a function that works with both
JsonArray
andJsonObject
?
Deserialization
-
Error:
invalid conversion from 'const char*' to 'int' [-fpermissive]
★★★★★ - Why parsing fails?★★★
- Can I parse a JSON input that is too big to fit in memory?★
-
Error:
invalid conversion from 'const char*' to 'char*' [-fpermissive]
★ - The first parsing succeeds, why do the next ones fail?
- Can I parse data from a stream?
-
How to iterate over a
JsonVariant
? - Parsing succeeds but I can't read the values!
- Can I access to object member by its index, instead of its key?
- How to know the type of a value?
- Why is the input modified?
Known problems
- Error: Ambiguous overload for 'operator='★
- ESP32
-
Error: undefined reference to
__cxa_guard_acquire
and__cxa_guard_release
- Warning: ignoring packed attribute because of unpacked non-POD field
- Atmel Studio
- Arduino Library Manager doesn't list the latest versions of ArduinoJson
- Error: 'equals' is not a member of 'ArduinoJson::Internals::StringTraits<const int&, void>'
- Sloeber Arduino Eclipse Plugin
- CodeBender
- Adafruit WICED Feather
- Warning: floating constant exceeds range of 'double'
- Arduino Zero, mkr1000 and all boards based on SAMD21
- Compilation fails after upgrading the library
Serialization
- How to create complex nested objects?★★
- Why ArduinoJson is slow?
- Using a loop, why are values all the same?
-
How to insert a
null
? - The first serialization succeeds, why do the next ones fail?
- How to compute the JSON length?
- How to prevent string escaping?
- Why are some parts missing?
- Why does the generated JSON document contain garbage?