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1. 

   leaflabsandy
   Member

   A direct challenge to the Maple A Team ... Scanf

   Since the Maple has many more comports than the standard Arduino
   there is one command/function that the Arduino design team
   refused or could not or would not implement - Scanf. This command/funtion
   is badly needed on any microcontroller with multiple serial ports.

   The scanf() function reads input from stdin, according to the given format,
   and stores the data in the other arguments. It works a lot like printf(). ...

   Is the Maple A Team up to this task?

   Posted 5 years ago #
2. 

   perry
   Administrator

   Can do, shouldn't be too hard.

   Mostly the hard part is coming up with a friendly API for doing so.

   Posted 5 years ago #
3. 

   gbulmer
   Moderator

   Do you mean 'real' C standard scanf (or fscanf) functionality?
   Like this: http://www.opengroup.org/onlinepubs/009695399/functions/scanf.html

   or would you be happy with a subset of that functionality?

   Posted 5 years ago #
4. 

   leaflabsandy
   Member

   'real' C standard scanf - would make serial input easy.

   Posted 5 years ago #
5. 

   perry
   Administrator

   'Real' scanf.

   printf/scanf are already implemented and come as part of newlib (libc). all that really needs to be done is to implement a handful of lower level newlib syscall stubs to read/write out a uart.

   see libmaple/syscalls.c for where they are in the libmaple tree.

   I can put it on my stack, or if somebody wants to implement it, patches are welcome.

   Posted 5 years ago #
6. 

   leaflabsandy
   Member

   Having both scanf and printf would be even better!
   If both functions are already in the "library-libc" and only
   the "hooks" are needed to attached to the Uart(s) then
   by having both commands, would it greatly increase the
   Maple's overhead?

   Posted 5 years ago #
7. 

   poslathian
   LeafLabs

   be prepared to burn a non negligible amount of your flash! I managed to get by with atoi and int2str that were hand coded and came in at only an extra k. Pull in printf and be prepared to spend 25k of program rom. Of course, that might not be a huge deal for a lot of projects.

   Posted 5 years ago #
8. 

   perry
   Administrator

   There are newlib-supplied iprintf/iscanf functions that do not support floating point specifiers are are approximately half the size of their larger brothers.

   I'll try to do the plumbing needed today to let you read out/into the serial port. If you look at syscalls.c, it already used to do that--I commented those lines out after I removed the stm32 peripheral library.

   Posted 5 years ago #

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