Can you use FDS4port from different cogs?

T Chap

I have run out of cogs and have a free port on the 4port. It would be great if two different cogs could use the same 4port. Is something like this even possible? At the moment there are other problems to solve before I can even test the idea.



obj
ser : "FDS4port"

cog1 ser.str(0, string("Hello world"))
cog2 ser.str(1, string("Hello world"))

Timmoore

Do you mean pcFullDuplexSerial4FC? Yes you can use it from multiple cogs. If you use multiple cogs to the same serial port then you have to deal with the chars interleaving but it will work.

T Chap

Actually the example shown is not the real need, it is for 4 different serial i/o's to 4 different external devices.

Thanks

FullDuplexSerial4port : first port is using parity on receive (10 bits) where the other 3 ports show 9 bits

Post Edited (Todd Chapman) : 12/6/2009 7:17:21 AM GMT

StefanL38

it depends on from which file you want to do the calls of the FDS4-methods.

As long as ALL calls like

ser.str(0,...
ser.str(1,...

ser.tx(2,byte...

are in the ONE and SAME file you can do so.

You can't access methods or variables across *.spinfiles directly
If the calls are in DIFFERENT *.spin-files it will ONLY work with modifying the code

For explaining this in detail it would be good if you describe your application in detail
in which file is the FDS4-object started and in which *.spin-files do you want to use
calls to the FDS4-methods

best regards

Stefan

Timmoore

You can include pcFullDuplexSerial4FC in multiple files. Start should be called once and all the uses of the object will use the same shared cog for tx/rx. This is how I use it. e.g. Its included multiple times, 1 serial port is for pc debug, used in lots of files/cogs, you get interleaving of the text but its ok for debugging. gps uses 1 port, camera uses another, etc. each port called by a different cog.

StefanL38

Aha ?! really ?!?? Maybe this discovered a lack of understanding of me how objects work.
I would like to clarify this.

If you want to use an object in different *.spin-files each file has to have a codeline

OBJ
  FDS4 : "pcFullDuplexSerial4FC"

As far as I understand it this means EVERY file where this codeline is defined
stores code in the HUB-RAM. So if the object is defined in two different files
all the code is stored two times in HUB-RAM and all the pointers like

  rxbuff_ptr            long      0                   '32 longs for per port buffer hub ptr
  rxbuff_ptr1           long      0
  rxbuff_ptr2           long      0
  rxbuff_ptr3           long      0
  txbuff_ptr            long      0
  txbuff_ptr1           long      0
  txbuff_ptr2           long      0
  txbuff_ptr3           long      0

of each instance point to different HUB-RAM adresses

Now what Timmoore is saying that the object is stored only ONCE in HUB-RAM and as all the pointers are in the DAT-section you can use this pointers across *.SPIN-files

Is this correct ?

best regards

Stefan

Timmoore

Code is shared across instances, variables in VAR sections are duplicated for each instance, variables in DAT are shared. You need to code round multiple read/write to these shared variables which is why you see interleaved chars if sending to the same serial port from multiple cogs.

T Chap

Thanks for the input fellows.

The FullDuplexSerial4Port did exactly what I was hoping.

Below is just an oversimplified example of what is really happening, all 4 ports working simultaneously. Port 3 is actually
an LCD, which will print from any of the other ports, including the new cog.

VAR
   byte  buffer1, buffer2, buffer3, buffer4

OBJ 
  ser    :  "FullDuplexSerial4Port"

PUB MainProgram
    Start4port          'set all i/o, baud
    cognew(newprogram, @newstack)
    repeat
      buffer0  := ser.rx(0)    'read port 0
      buffer2  := ser.rx(2)    'read port 2
      buffer3  := ser.rx(3)    'read port 3        

PUB newprogram
    repeat 
      buffer1  := ser.rx(1)    ''read port 1

Post Edited (Todd Chapman) : 12/7/2009 5:09:48 AM GMT