John M. Kelly
Member
I am new to B4J and I am having trouble understanding AStream_NewData. I understand what it is for and I have it working (I think). But I don't know why and thus I cannot trust it.
Say at time T0 I send 33 bytes of data from a microcontroller to a PC via a USB-Serial port operating at 57.6K. Sub AStream_NewData picks it up, reads the 33 bytes and creates a desired text string from those bytes. In "Sub AStream_NewData" I used no end of line, I had no prefix, nothing to end the NewData. Two seconds later at T2 I again send the same 33 bytes via the USB-Serial port to the PC. I get the same 33 bytes and the same string. Why????? Why isn't it 66 bytes? Why didn't AStream_NewData just keep creating a longer byte array? Why did it "reset" to start byte collection over?
Now, lets say I want to "force" a reset after exactly 33 bytes. How can I terminate the incoming byte array immediately after 33 bytes.
Now, say I want to end the NewData array when a particular symbol comes in. Say when a "!" is received. How do I do that? I cannot use the traditional CRLF because I am using byte codes 10 and 13 for other purposes.
And lets say I know I am sending exactly 33 bytes. Can I just receive the first incoming byte and then go to "sleep" until such time that I can be sure that all 33 bytes have been received?
So what automatically terminates the NewData byte string (if anything)?
Okay, as I understand the matter (and this may be totally wrong) I would need to attach a 4 byte number to use AStream in prefix mode. So, if I will be sending 33 bytes I would need to send 0x00+0x00+0x00+0x21 (in hex), right. Or do I? Can I just add a prefix 0x21 and then send the 33 bytes?
Finally, I could use the help of an Alpha tester. If you are a maker, use 830 point boards, and would like to use either your PC and/or Android device as readout let me know.
Say at time T0 I send 33 bytes of data from a microcontroller to a PC via a USB-Serial port operating at 57.6K. Sub AStream_NewData picks it up, reads the 33 bytes and creates a desired text string from those bytes. In "Sub AStream_NewData" I used no end of line, I had no prefix, nothing to end the NewData. Two seconds later at T2 I again send the same 33 bytes via the USB-Serial port to the PC. I get the same 33 bytes and the same string. Why????? Why isn't it 66 bytes? Why didn't AStream_NewData just keep creating a longer byte array? Why did it "reset" to start byte collection over?
Now, lets say I want to "force" a reset after exactly 33 bytes. How can I terminate the incoming byte array immediately after 33 bytes.
Now, say I want to end the NewData array when a particular symbol comes in. Say when a "!" is received. How do I do that? I cannot use the traditional CRLF because I am using byte codes 10 and 13 for other purposes.
And lets say I know I am sending exactly 33 bytes. Can I just receive the first incoming byte and then go to "sleep" until such time that I can be sure that all 33 bytes have been received?
So what automatically terminates the NewData byte string (if anything)?
Okay, as I understand the matter (and this may be totally wrong) I would need to attach a 4 byte number to use AStream in prefix mode. So, if I will be sending 33 bytes I would need to send 0x00+0x00+0x00+0x21 (in hex), right. Or do I? Can I just add a prefix 0x21 and then send the 33 bytes?
Finally, I could use the help of an Alpha tester. If you are a maker, use 830 point boards, and would like to use either your PC and/or Android device as readout let me know.
