Re: PIC under Linux developpement Howto

Christopher Bergeron wrote:
> I'm going to have to second this one.  However, there's a part of me
> that thinks that having choices will be confusing to newbies.

Well. in the light of all this reaction, allow me to amend my original
suggestions:

 * C is most useful IMHO - more useful than dumbed-down high-level langs
   like BASIC, and less annoying for the newcomer than assembler, and
   easy to interface with assembler

 * another alternative is PyAstra - a cut-down Python to PIC assembler
   compiler - but Python scares many folks because whitespace is
   syntactically significant, so should probably stick with C instead

 * assembler is menial - justified only when performance or environment
   limitations necessitate it - you get way more functionality per litre
   of blood/sweat/tears when programming in higher level languages,
   because it's way easier to concentrate on the 'what' without being
   constantly distracted by the 'how' - basic stuff like parameter
   passing, data structures, and (in the 16F case) those damn fragmented
   program/data memory segments etc etc - C compilers spare the user of
   all that crap

 * a howto should take the user, step by manageable and verifiable
   step, from a bag of parts and an internet connection through to a
   board with a blinking 'hello world' LED, and then through to other
   PIC stuff like ADC, PWM, USART etc - without them needing to spend
   a cent on anything other than hardware

 * I'd suggest sdcc - it's not the prettiest C compiler, but it can
   do the simple stuff, and it's speech/beer free, and available on
   all decent linux distros

 * I'd suggest the 16F876/7 as the main chip, since it can self-program,
   it has the on-chip goodies, and it's cheaper than the 18Fs; upgrading
   from 16F to 18F is orders of magnitude easier than the other way
   round; also it's got less memory scarcity than (say) the 16f873

 * for a programmer - probably best to pick one that:
    - has minimal parts count
    - can work via serial port (PCs usually have 2 serial ports but only
      one parallel port, and the parport is often in use with a printer)
    - has PCB artwork and parts list, plus working Linux-compatible
      on-chip and on-host programming software, freely downloadable from
      the net (I bought a great programmer kit from Jaycar, but can't
      recommend this because Jaycar only has stores in Aus and NZ, and
      this would be a pain for people in other countries)

 * for a bootloader - I'm personally using TinyPIC Bootloader on my
   18Fs, but haven't got this working on the 16Fs (so I use the PicForth
   Serial Monitor on those chips) - need to choose a bootloader which:
    - is written in assembler and builds ok on gputils, or is written in
      C and builds ok with sdcc
    - has a working host client written in a common language, that is
      easily built with reliable results without dragging the user
      through autocrap/dependency hell (as linux progs can sometimes do)

 * tutorial should include a section on gpsim, using .map and .lst files
   so user can correlate the high-level code to the raw binary; should
   walk user through:
    - setting up gpsim config
    - single-stepping and use of breakpoints
    - inspecting SFRs and user data memory contents

This approach eliminates the complication of multiple
chips/languages/programmers.

-- 
Cheers
David