Uart Break in C, works, but how?

Clock Loop · 2020-09-03 17:55

Heres the c code that works to send a UART break.

I don't see how its doing that.


#include "wifi.h"


int main()
{
  wifi_start(31, 30, 115200, WX_ALL_COM);
}

I don't see what wifi_start is doing that generates a UART break.

Chasing down c code is like Alice tumbling down the rabbit hole.

I am simply trying to do the same in SPIN.

iseries · 2020-09-03 18:14

Here is the code for wifi_start function. You can see how the break is generated:

fdserial *wifi_start(int fromDO, int toDI, int baud, int comSelect)
{ 
  #ifdef WIFI_DEBUG
  print("wifi_start\r");
  #endif  //WIFI_DEBUG
  
  wifi_buf = wifi_bufferSize(wifi_buf_size);

  wifi_pin_do = fromDO;
  wifi_pin_di = toDI;
  wifi_baud = baud;
  wifi_comSelect = comSelect;
  
  if(comSelect == USB_PGM) 
  {
    simpleterm_fromTxDo = fromDO;
    simpleterm_toRxDi = toDI;
  }    
  
  wifi_simpletermSuspend();
  
  wifi_fds = fdserial_open(wifi_pin_do, wifi_pin_di, 0b0100, wifi_baud);
 
  // Break condition
  pause(10);
  low(wifi_pin_di);
  pause(1);
  input(wifi_pin_di);
  pause(1);
  
  wifi_simpletermResume();
  
  return wifi_fds;
}

Mike

Clock Loop · 2020-09-03 18:16

Ok, after luckily searching the 32420-Parallax-Wi-Fi-Module-API-v1.0, it says this:

3. Via a Break Condition on the Serial interface itself
          a. Set the DI pin low for ≥ 30/baud rate,    seconds.

Lol, I was attempting to do this and searching the net, these forums etc, for the word break, and those .h files...
I was looking for 1 hour, and didn't even think to search the api... GAH.. time for a outdoor humming bird viewing break.

SCREEEENS ARE ZOMBIFING ME....

This works to generate a break to the WX module.
Thats why the spin WX code wasn't working.

  dira[WXDI]~~          ' Set direction to output                        
  outa[WXDI]     := 0 

  waitcnt(80_000_000 + cnt)    'wait one second.
                               
  FDS.start(WXDO,WXDI,0,115200)   ' Prop rxpin, Prop txpin, mode,baudrate

DEBUG output from WX debug pin.

UART break detected. Switching on SSCP command parsing.

YAAAY!

*moves notch one up. only 1 million more to go...

Clock Loop · 2020-09-03 18:25

iseries wrote: »

Here is the code for wifi_start function. You can see how the break is generated:

LOL, I still don't see where it puts the DI pin low for a bit in that c code.

Gah, I don't like C... I do like spin.

iseries · 2020-09-03 18:28

Scroll down to where is says "Break Condition". It sets the pin low for 5 milliseconds.

I hate spin but love C.

Mike

Clock Loop · 2020-09-03 18:38

Hah, I was searching all the .h files that are listed as INCLUDE. I did not search any .c file...
Until you told me that. I didn't look in the .c file because it wasn't a #include.
I clearly don't know enough about c to C. (see)

iseries · 2020-09-03 18:43

Right, the include files are usually not code but definitions.

Mike

Uart Break in C, works, but how?

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