# How to packed JSON object over serial port (Serialise JSON object)
**URL:** https://discourse.processing.org/t/how-to-packed-json-object-over-serial-port-serialise-json-object/34686
**Category:** Electronics (Arduino, etc.)
**Created:** [January 17, 2022, 1:42am UTC](https://discourse.processing.org/t/how-to-packed-json-object-over-serial-port-serialise-json-object/34686 "2022-01-17T01:42:18Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@avong](https://discourse.processing.org/u/avong)
#### Post date: [January 17, 2022, 1:42am UTC](https://discourse.processing.org/t/how-to-packed-json-object-over-serial-port-serialise-json-object/34686/1 "2022-01-17T01:42:18Z")
> please format code with \ button \* [homework policy](https://discourse.processing.org/faq/#homework) \* [asking questions](https://discourse.processing.org/t/2147)
> I wish to set PC to communicate with my microcontroller over serial port.
> The data format i use JSON.
> The microcontroller to PC is working well but i can not send from the PC to the controller.
> write function has no support for JSON object data type.
How can I achieve that?
> \<
> JSONObject payLoad=null;
> payLoad.setBoolean(“POWER”, true);
> payLoad.setBoolean(“PUMP”, true);
> payLoad.setInt(“VALUE”, 67);
```
// write(payLoad); // This will work.
>
how should i handle this?
```
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### Author:  [@SomeOne](https://discourse.processing.org/u/SomeOne)
#### Post date: [January 17, 2022, 2:40pm UTC](https://discourse.processing.org/t/how-to-packed-json-object-over-serial-port-serialise-json-object/34686/2 "2022-01-17T14:40:50Z")
I assume write function supports text. JSON is almost always transferred as text. JSON-objects are constructs of programming languages to help handling of JSON. Anyway payLoad.tostring() will give you your JSON-object as a string
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### Author:  [@avong](https://discourse.processing.org/u/avong)
#### Post date: [January 18, 2022, 5:21pm UTC](https://discourse.processing.org/t/how-to-packed-json-object-over-serial-port-serialise-json-object/34686/3 "2022-01-18T17:21:24Z")
I did as recommended. .
But I am left another challenge.
No error report but no data is transmitted.
I did it this way.
String str\_payload=payload.toString();
write (str\_payload);
---
### Author:  [@avong](https://discourse.processing.org/u/avong)
#### Post date: [January 18, 2022, 9:17pm UTC](https://discourse.processing.org/t/how-to-packed-json-object-over-serial-port-serialise-json-object/34686/4 "2022-01-18T21:17:44Z")
One other thing i notice:
anytime I am packing of JSON object inside the function call to SerialPortWrite.
I get null pointer to the json object instance.
Now to solve it my own way.
I use String to manually pack the JSON struct and then forward it to the serial write.
Something like:
String payload ="{";
payload +=“key:”;
payload +=str(value);
payload +="}";
write(payload);
This truly is crook way but since the data size is small from the PC to my microcontroller. I dont mine.
I still open to learn should someone know better way to handle that.
Something is did not mention before.
A call to Serialport is handle by thread, something like thread (“SerialPortWrite”)
Anytime i need to send data to microcontroller will create the
thread(“SerialPortWrite”);
could this be the reason?
---
### Author:  [@SomeOne](https://discourse.processing.org/u/SomeOne)
#### Post date: [January 19, 2022, 3:27am UTC](https://discourse.processing.org/t/how-to-packed-json-object-over-serial-port-serialise-json-object/34686/5 "2022-01-19T03:27:19Z")
What does documentation tell you?
Quite often print() happens instantly where write() puts stuff to a buffer and you need another function call to to send or process the buffer.
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### Author:  [@avong](https://discourse.processing.org/u/avong)
#### Post date: [January 20, 2022, 5:44am UTC](https://discourse.processing.org/t/how-to-packed-json-object-over-serial-port-serialise-json-object/34686/6 "2022-01-20T05:44:01Z")
If my understanding is is right.
"write " function send data to the serial port. It send data out immediately they are loaded in it
while “print/println” send data to the console.
These are truly different.