G80 UART 512kbps baud rate

NETMF & Gadgeteer
1

Hi

Do G80 h/w and .netmf libraries support 512kbps baud for UARTs?

Thanks.
Aavinan

2

Probably not but why not connect a scope and send a byte to try it out.

If you are receiving at that rate then you will probably end up losing bytes if data come in bursts. You need a device with more RAM.

3

G80 datasheet, section 7.8 mentions UART bauds fom 2400 to 921600 are supported.
I am going to use RS422 driver that supports 3Mbps for this application.

I will try some codes w/ 512Kbps with my board (RS232) and update here later. Thanks.

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4

Application is not a real time system. Just a baud rate converter. As for data packet size, could be 50 bytes each direction (TX, RX) per second. Receive packet from one side, send to other side and vice versa.

A friend is stuck with a camera and its controller that support only 512kbps over RS422. But a fiber converter that links camera and controller support only 115.2kbps.

So am going to drop G80 board to convert baud rates.

Welcome more inputs from this forum.

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5

Tested my G80 based board’s UART by communication to a Moxa USB to RS232 converter.

Data transfer is good with standard baud rates of 9600, 19200, 38400, 57600, 115200, 230400, 460800, 921600.

However with 512000 baud, data bytes are missing and jumbled.

Could be the below factors,

  1. USB to RS232 converter may not support non-standard baud.
  2. NETMF libraries may not support non-standard baud.

Anybody worked on such a problem before? Am i missing something? Suggestions welcome.

6

What’s the error in the calculation for that baud rate on the G80?

It sounds more like the USB to RS232 because the G80 works at the 921600 rate???

7

Error % is 0.16%

(921600???) I just ran a simple one time tx, rx of 31 bytes at 921600. That went well.
I am aware that G80 cannot handle high data xfer rates.
I am wondering if at all, G80 can run at 512kbps.

8

Its the USB to RS232 converter. Another one with FTDI chip works.

50 bytes in and out per second at 512000 baud, 100 cycles completed, no problem so far.

Looking for a compatible RS422 transceiver, probably with galvanic isolation.

Thanks Dave & Gus.

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