An Easy One

SteveWoodrough

This one is easy, just hard for me.

I’m experimenting with Tim Moores PC Full Duplex Serial 4FC getting data from a GPS and sending to an LCD or PST, etc.

The sample original program had a line like this.

cog := cognew(BackGround,@stack) + 1                  'Start the background Cog  

pub BackGround
'Process gps and camera receive characters
'minimize processing in this cog, i.e. dont send to serial ports e.g. debug
'dont call waitcnt, etc. Dont call blocking receives from serial ports - use rxcheck
  repeat
    
    gps.GetNMEALine

As I looked through the GPS_IO “GPS.” object I saw a method that read

PUB readNEMA
' if start is called this processes reads from GPS on a COG
  repeat
    GetNMEALine
      

So I got the bright idea to change the cog start from above to:

cog := cognew(gps.readNEMA,@stack) + 1      

OF course that does not work, but I do not understand why. The functioning first version starts a local method in another cog and that method repeats a method from a referenced object, GetNMEALine.
The non-functioning second approach starts a referenced object method in another cog, and that referenced object method repeatedly references another method within the same referenced object.

In theory, both are going to the same place, but the first works and the second does not.

Hopefully this all makes sense. I’ve attached the basic code.

Thank You! Steve

kuroneko

cog := cognew(gps.readNEMA,@stack) + 1      

This would start a PASM cog if gps.readNEMA were ever going to return a result. As this method is stuck in an endless loop the cognew is stuck as well. Starting a SPIN cog requires a single method without object notation.

Duane Degn

SteveWoodrough wrote: »

I’m experimenting with Tim Moores PC Full Duplex Serial 4FC

Tracy Allen cleaned up Tim's code and fixed a few bugs. Here's Tracy's improved object.

Attempting to put what kuroneko stated in my more simplistic words. Don't use "cognew" across objects.

SRLM

Although you should be able to wrap the gps.readNEMA in a local function, and use that in the cognew.

SteveWoodrough

Thanks guys. I thought I was paying attention all these years, and repeatedly discover that what I don't know would fill a very large bucket.