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MOD 5213 UART 0 RTS and CTS

Posted: Tue Jul 18, 2017 4:26 pm
by Vernon
I have a problem with re-flashing my MOD5213 board apparently due to the lack of hardware flow control. It used to work without it, perhaps in older versions of these modules, but no longer does. They tell me that it needs to be enabled.

What pins are used by RTS/CTS on the UART that is used to flash the chip (UART 0)

I looked at the schematic MOD-DEV-40 R1P3 and on J4, that is UART 0, there is no flow control connected. Nothing on that print is labeled RTS or CTS for UART0.

Is there a new version of this board?

The problem is if I try to enter the download mode by typing A - I get scrambled letters like one would with an incorrect baud rate. Serial communication within the application works fine but I can no longer flash the chips and seem to have "bricked" two of them.

Re: MOD 5213 UART 0 RTS and CTS

Posted: Tue Jul 18, 2017 4:59 pm
by Vernon
What I get is shown in the picture. This is two different PCs. If I go right into the application (the top of each picture) everything is fine. If I press A to reflash I get some incoherent letters - more of them on one computer. I could still reflash in the past but have now bricked two of them.

Re: MOD 5213 UART 0 RTS and CTS

Posted: Mon Jul 24, 2017 1:40 pm
by Vernon
The problem turned out to be a certain genre of Ebay 3.3V TTL to RS-232 level shifters. They all work in the application but some do not work correctly (for unknown reasons) when you type A.

http://www.ebay.com/itm/RS232-Serial-Po ... 2749.l2649

The above works great. Leave the RTS and CTS open.

Re: MOD 5213 UART 0 RTS and CTS

Posted: Tue Aug 01, 2017 10:56 am
by joepasquariello
Hi Vernon,

FYI, the reason you don't see CTS and RTS used is that Netburner's serial transfers use Xon/Xoff flow control. This is software flow control, with Xon and Xoff characters in the data stream, so no pins other than RX and TX.

Joe