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PICAlison
Joined: 11 Jun 2021
Posts: 10
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| RS232 putc and putc_send |
 Posted: Mon Jul 26, 2021 6:46 am |
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I've setup my uart and if I don't use flow control I can send out data using 'putc'. But when I turn the flow control on (RTS/CTS) I have to follow each putc with a putc_send.
It appears that putc is puts the byte it in the transmit buffer and putc_send transmits it. Is this right?
It does seem like that when I read the manual.  |
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temtronic
Joined: 01 Jul 2010
Posts: 9228
Location: Greensville,Ontario
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| Posted: Mon Jul 26, 2021 6:51 am |
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need to know ...
Which PIC, which Compiler version and plase post a small, compilable program that show us what you're doing...
Jay |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19516
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| Posted: Mon Jul 26, 2021 7:10 am |
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Yes. It depends massively on whether you are using a TRANSMIT_BUFFER,
and whether you are using the TXISR option or not. |
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PICAlison
Joined: 11 Jun 2021
Posts: 10
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| Posted: Mon Jul 26, 2021 8:18 am |
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Here's my setup directive for the uart:
| Code: | // with flow control
#use rs232(stream=BLUETOOTH, UART1, baud=115200, RTS=PIN_B5, CTS=PIN_B4, RECEIVE_BUFFER=20, TRANSMIT_BUFFER=20, stream=UART_PORT1, xmit=PIN_B14, FLOW_CONTROL_MODE, rcv=PIN_B15, parity=N, bits=8, stop=1, errors) |
This is how I am using it:
| Code: | putc('$', BLUETOOTH);
putc_send(BLUETOOTH); |
The help for putc says "sends a character over the RS232 XMIT pin" and putc_send() says "transmit bytes loaded in transmit buffer over RS232".
So it doesn't sound like I need the putc_send, but I do? |
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PICAlison
Joined: 11 Jun 2021
Posts: 10
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| Posted: Mon Jul 26, 2021 8:24 am |
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Update: I need a TXISR in the setup to enable to us "TBE interrupt for transmitting data".
Default is NOTXISR ...  |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19516
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| Posted: Mon Jul 26, 2021 9:32 am |
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Yes.
As I said:
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and whether you are using the TXISR option or not.
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The key is that this is what allows the TRANSMIT_BUFFER to actually send
without you signalling to do so.... |
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