Serial1.availableforwrite returns 0

[jayang727]

I discovered that Serial1.availableforwrite always returns 0. I suspect this is causing blocking and interrupting thread1 and 2 from properly receiving and saving.

Is this normal for OLA or do I need to change some config to set up a non-zero buffer to Tx?

Thank you.

[PaulZC]

Hi @jayang727 ,

I cannot find Serial1.availableforwrite anywhere in the code. Did you mean Serial1.available() ? Unless this is something to do with the Print class ?

Can you please tell me which line(s) in which file you are referring to?

Best wishes,
Paul

[jayang727]

Hi Paul, Apologies for the confusion. I was actually modifying the firmware to include some outgoing communication protocol to send commands to the external sensor. I was discovering that whenever I used Serial1.write while the logger was receiving data, the received/logged data was incomplete. I was suspecting the write() was maybe blocking. I added Serial1.availableforwrite to monitor the available tx buffer at the end of setup() and during loop() to the original firmware, which doesn't have any outgoing data serial1, and discovered that the available tx buffer was always 0. Perhaps this is not the right venue to ask about the tx buffer for OLA? Or perhaps I'm misunderstanding availableforwrite? Baud rate:230k Data: ~60bytes at 25hz Thank you so much for your help. Hj

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On Sun, Jul 2, 2023, 00:20 Paul ***@***.***> wrote: Hi @jayang727 <https://github.com/jayang727> , I cannot find Serial1.availableforwrite anywhere in the code. Did you mean Serial1.available() ? Unless this is something to do with the Print class ? Can you please tell me which line(s) in which file you are referring to? Best wishes, Paul — Reply to this email directly, view it on GitHub <#1 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/BA7QK263ZM7SNAMWQR3XSDLXOEOKDANCNFSM6AAAAAAZ3GXE2I> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[PaulZC]

Hi Hj (@jayang727 ),

With version 2 of the Apollo3 core, it looks like availableForWrite is inherited from the mbed Print class:

https://github.com/sparkfun/arduino-mbed-bridge/blob/25fe1981fe509217059f093395372e1ffcbd6335/core-api/api/Print.h#L61

But it was implemented correctly in version 1 of the core:

https://github.com/sparkfun/Arduino_Apollo3/blob/87a33ce12049ff10c6d0d7e6ab9038e4d874b36e/cores/arduino/ard_sup/uart/ap3_uart.cpp#L92-L95

Please ask your question again in the Artemis forum: https://forum.sparkfun.com/viewforum.php?f=172
paulvha knows much more about the Apollo3 (mbed) core than I do and will be able to give you a much better answer.

Best wishes,
Paul